When It Comes to Fish Oil, More Is Not Better | Chris Kresser
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When It Comes to Fish Oil, More Is Not Better

by Chris Kresser

Last updated on


Update: I now recommend Extra Virgin Cod Liver Oil from Rosita as my preferred cod liver oil product. For more information, read this article. You can purchase EVCLO here.

Article summary

  • The benefits of fish oil supplementation have been grossly overstated
  • Most of the studies showing fish oil benefits are short-term, lasting less than one year
  • The only fish oil study lasting more than four years showed an increase in heart disease and sudden death
  • Fish oil is highly unstable and vulnerable to oxidative damage
  • There’s no evidence that healthy people benefit from fish oil supplementation
  • Taking several grams of fish oil per day may be hazardous to your health

A new study was recently published showing that 3g/d of fish oil in patients with metabolic syndrome increased LDL levels and insulin resistance.

Unfortunately, I don’t read Portuguese so I can’t review the full-text. But this study isn’t alone in highlighting the potential risks of high-dose fish oil supplementation. Chris Masterjohn’s latest article on essential fatty acids, Precious yet Perilous, makes a compelling argument that fish oil supplementation – especially over the long-term – is not only not beneficial, but may be harmful.

This may come as a surprise to you, with all of the current media hoopla about the benefits of fish oil supplementation. Yet the vast majority of the studies done that have shown a benefit have been short-term, lasting less than one year. The only trial lasting more than four years, the DART 2 trial, showed that fish oil capsules actually increase the risk of heart disease and sudden death.

A 2004 Cochrane meta-analysis of trials lasting longer than six months suggests that the cardiovascular benefits of fish oil have been dramatically over-stated. They analyzed 79 trials overall, and pooled data from 48 trials that met their criteria. The only effect that could be distinguished from chance was a reduced risk of heart failure. Fish oil provided no reduction in total or cardiovascular mortality.

Too much fish oil can wreak havoc in your body

Omega-3 fatty acids are highly vulnerable to oxidative damage. When fat particles oxidize, they break down into smaller compounds, like malondialdehyde (MDA), that are dangerous because they damage proteins, DNA, and other important cellular structures.

A study by Mata et al demonstrated that oxidative damage increases as intake of omega-3 fat increases. The results of this study were summarized in the Perfect Health Diet, by Paul and Shou-Ching Jaminet:


Notice the clear increase in TBARS (a measure of oxidative damage of the LDL particle) with omega-3 fat. It’s important to note that this was only a 5-week trial. If it had gone on for longer than that, it’s likely the oxidative damage caused by omega-3 fats would have been even worse. This isn’t surprising if you understand the chemical composition of fats. Polyunsaturated fats (PUFA) are highly vulnerable to oxidative damage because they’re the only fatty acids that have two or more double bonds, and it’s the carbon that lies between the double bonds that is vulnerable to oxidation (as shown in the figure below):

diagram of chemical structure of EPA

Another thing worth noting, if you haven’t already, is that intake of saturated and monounsaturated fats does not increase oxidative damage by a significant amount. This is illustrated in both the table and the diagram above: saturated fats have no double bonds, which means they are well protected against oxidation. MUFA is slightly more vulnerable, since it does have one double bond, but not nearly as much as PUFA which has several double-bonds.

A randomized, double blind, placebo-controlled trial likewise showed that 6 grams per day of fish oil increased lipid peroxides and MDA in healthy men, regardless of whether they were supplemented with 900 IU of vitamin E. And consumption of fresh, non-oxidized DHA and EPA has been shown to increase markers of oxidative stress in rats.

Fish oil not as beneficial as commonly believed

To be fair, at least one review suggests that fish oil supplementation is beneficial in the short and even intermediate term. A recent meta-analysis of 11 trials lasting more than one year found that fish oil reduced the relative risk of cardiovascular death by 13 percent and the relative risk of death from any cause by 8 percent.

But the effect seen in this review was mostly due to the GISSI and DART-1 trials. They found that fish oil may prevent arrhythmia in patients with chronic heart failure and patients who have recently survived a heart attack.

However, there is no evidence that people other than those with arrhythmia and chronic heart failure benefit from taking fish oil or that doses higher than one gram of omega-3 fatty acids per day provide any benefit over smaller doses. And then there’s the rather disturbing result of the DART-2 trial, the only fish oil study lasting more than four years, showing an increase in heart disease and sudden death.

It’s logical to assume the effects of oxidative damage would take a while to manifest, and would increase as time goes on. That’s likely the reason we see some benefit in short- and intermediate-term studies (as n-3 displace n-6 in the tissues), but a declining and even opposite effect in the longer-term DART-2 trial (as increased total PUFA intake causes more oxidative damage).

The danger of reductionist thinking in nutritional research

The current fish oil craze highlights the danger of isolated nutrient studies, which unfortunately is the focus of nutritional research today. Kuipers et al. eloquently described the risks of this approach in a recent paper:

The fish oil fatty acids EPA and DHA (and their derivatives), vitamin D (1,25-dihydroxyvitamin D) and vitamin A (retinoic acid) are examples of nutrients that act in concert, while each of these has multiple actions(7,8).

Consequently, the criteria for establishing optimum nutrient intakes via randomised controlled trials (RCT) with single nutrients at a given dose and with a single end point have serious limitations. They are usually based upon poorly researched dose–response relationships, and typically ignore many possible nutrient interactions and metabolic interrelationships.

For instance, the adequate intake of linoleic acid (LA) to prevent LA deficiency depends on the concurrent intakes of α-linolenic acid (ALA), γ-LA and arachidonic acid (AA). Consequently, the nutritional balance on which our genome evolved is virtually impossible to determine using the reigning paradigm of ‘evidence-based medicine’ with RCT.

Interest in fish oil supplementation started with observations that the Inuit had almost no heart disease. It was assumed their high intake of marine oils produced this benefit. While this may be true, at least in part, what was overlooked is that the Inuit don’t consume marine oils in isolation. They eat them as part of a whole-food diet that also includes other nutrients which may help prevent the oxidative damage that otherwise occurs with such a high intake of fragile, n-3 PUFA.

It’s also important to note that there are many other traditional peoples, such as the Masai, the Tokelau, and the Kitavans, that are virtually free of heart disease but do not consume high amounts of marine oils. What these diets all share in common is not a large intake of omega-3 fats, but instead a complete absence of modern, refined foods.

Eat fish, not fish oil – cod liver oil excepted

That is why the best approach is to dramatically reduce intake of omega-6 fat, found in industrial seed oils and processed and refined foods, and then eat a nutrient-dense, whole-foods based diet that includes fatty fish, shellfish and organ meats. This mimics our ancestral diet and is the safest and most sane approach to meeting our omega-3 needs – which as Chris Masterjohn points out, are much lower than commonly assumed.

Some may ask why I continue to recommend fermented cod liver oil (FCLO), in light of everything I’ve shared in this article. There are a few reasons. First, I view FCLO as primarily a source of fat-soluble vitamins (A, D, K2 and E) – not EPA and DHA. Second, in the context of a nutrient-dense diet that excludes industrial seed oils and refined sugar, and is adequate in vitamin B6, biotin, calcium, magnesium and arachidonic acid, the risk of oxidative damage that may occur with 1g/d of cod liver oils is outweighed by the benefits of the fat-soluble vitamins.

So I still recommend eating fatty fish a couple times per week, and taking cod liver oil daily, presuming your diet is as I described above. What I don’t endorse is taking several grams per day of fish oil, especially for an extended period of time. Unfortunately this advice is becoming more and more common in the nutrition world.

More is not always better, despite our tendency to believe it is.

Note: As always, I’m open to discussion and dissenting views. But please don’t link to short-term studies on the efficacy of fish oil, because as I’ve explained in this article, it’s the long-term effects that we’re primarily concerned with. I’d be interested in seeing any studies longer than 2 years showing that 1) fish oil benefits extend beyond reducing arrhythmia in patients with chronic heart failure and patients who have recently survived a heart attack, 2) doses higher than 1g/d produce a larger benefit than doses of 1g/d, and (most importantly) 3) doses of >1g/d or higher do not increase the risk of heart disease or death


Join the conversation

  1. I tried high strength fish oil when it came out a few years ago. Only taking the recommended dose on bottle. After a few days I felt I was foggy and drunk. It happened no matter the brand. Never on normal fish oil capsules. I now only eat Salmon. Best to eat real food only, nature is already perfectly balanced no need to mess with it to extract only one component of a perfectly balanced combination.

  2. Thought I’d add my experience. Been taking small doses of fish oil for many years. Recently though, it so happened that I was on a very low omega-6 diet. I just decided to eat healthier, therefore the only oils I eat are olive oil and oils form meat and dairy. Since about a month or two, omega-3 been making me sick for about 48 hours every time I eat it.. Chia seeds and walnuts seem to make it the worst, but so does fish. I’d have very strange anxiety where I can’t seem to shut of negative thinking and I’ll feel I’m going crazy, also experiencing disassociation and feeling very sad in general. Normally, I feel very well mentally except for a few anxiety issues, but those are not usually related to sad feelings, just feeling nervous. I tried adding more omega-6, but still, any time I eat fish, walnuts or god forbid, chia seeds I’d get that “crazy” feeling for 24-48 hours…After that I’d be fine…Very weird. Any thoughts?

  3. I am an optometrist who just so happens to be very interested in nutrition and how poor diets are affecting my patients. I see dry eye so commonly, and a staple dry eye treatment is fish oil. We were taught to recommend 1000-2000mg of fish oil to patients with dry eye. The products that we are taught to use are highly filtered fish oil with the ethyl alcohol removed so that is better absorbed (brands that I believe do this are Nordic Naturals and PRN). They are sourced from anchovy, sardines, and mackerel. It is assumed that patients are going to be taking these supplements long term. My question is, what is your take on this approach, and would you recommend doing something different with my dry eye patient? Should I go against the fish oils my peers recommend and do cod liver oil instead? Also, some fish oil products also contain lutein and zeaxanthin which we recommend for macular health. Now I am afraid to recommend these long term.

    • Hi Shannon, thought I’d reply to your comment, it’s always great for me to speak to Optomotrists dealing with Dry Eye symptoms directly in patients.

      I head up a company that provides ‘triglyceride’ omega 3, this is omega 3 with the ethyl esters removed. In answer to your question, when you actually look at the studies the figures are not really showing Fish oil is dangerous, although some ‘writers’ have used it to create controversy.

      The DART 2 study actually showed that 18% of men taking fish oil died, whereas 17% of men eating fish died, it hardly seems possible to suggest Fish oil increases the risk of death. The fish oil group also had more serious health problems to start with.

      • Actually, I have one more question for you. Should I continue recommending the anchovies/sardine fish oil or should I switch to cod liver oil?

  4. I am 69 years old. People tell me I look to be in my early fifties. I have been taking 25 — 40 grams of fish oil per day for twelve or fifteen years now, with no apparent ill effects. I ate a sensible diet. I also work out at the gym every day—weights plus cardio.

    • What type of fish oil are you taking to provide you with 20 -40 grams per day? Are you aware of the potential excessive bleeding that could result in so much fish oil? FDA comments on GRAS (generally recognized as safe) up to 3 grams/day.


      • Apparently didn’t happen to him. Taking for 15 years!!! It is working for him. Not everyone is the same. I believe this article is to get me to take prescription drugs? ?, not all of us have the luxury to get fresh cod even twice a week. Try everything in moderation and keep track if it is working.

  5. It’s odd to me Chris that you decided to remove your support to Green Pastures and then go support another company who is less transparent about their practices than Green Pastures and doesn’t even disclose why they add vitamin E and then don’t tell you their source of it. Nordic Naturals and Carlson oils get their fish from the same ocean as Corganic and go through horrific processing to remove contaminants and then add synthetic vitamins back into their oils, what makes Rosita so special that they don’t process their oil? I think it was a poor move on your part and Green pastures has always been transparent and always disclosed its processes and labs and even re-did labs to double check. I’m not convinced Rosita/Corganic is as honest as you are saying.

  6. Some interesting points Chris, however the DART 2 study showed that 18% of men taking fish oil died, whereas 17% of men on fish died, it hardly seems possible to suggest Fish oil increases the risk of death.

    Also more importantly, the fish oil group we taking 3g of fish oil twice a week (maxepa). They don’t say exactly how much of that was omega 3, given the study date of 2003 we can assume it’s around 30% so 900mg of omega 3 twice a week. This is way less than even the recommended 500mg per day for everyone, (as opposed to the higher number that would be expected for people suffering from angina).

    How can you expect to see a reduced death risk when the amount of omega 3 taken was significantly less then needed?

    Also it was only in the EPA form, with no DHA, and we must assume the ethyl ester form. Absorption of ethyl esters is way less than it would be from fish, which is obviously in the triglyceride form. So in conclusion the amount of omega 3 in the fish oil supplementation group was completely inadequate.

    Plus the fish, veg and fish and veg groups were given no other dietary advice, how do we know what else they were eating, is it surprising that just simple healthy eating had the lowest death rate, if you are mixing your fish oil capsules twice a week with burgers and doughnuts?

    Also in the TBARS study, you fail to mention that it was conducted in vitro, and they point out in their discussion that animal studies that had shown this in vitro risk did not transfer to atherosclerotic risk in vivo.

    • Thank you Andy. I know this post & your comment is over a year old, but I greatly appreciate your counter points.

  7. My blood results today (this year) shows very high level of Vit B12, cholesterol level of 6.7 and LDL of 4.4.
    I do 90 mins gym 4 days a week and a fair bit of walking on other days. My non veg diet is very healthy with a lot of greens and fruits daily and all home cooked. I do not snack on chips and sweets, etc. However, I take about 4 -2000mgcapsules a day of Fish a I am allergic to fresh seafood. Could this be the reason for my strange reading?

    • What brand is the fish oil you are taking? The FDA says that dietary supplement manufacturers should not recommend taking more than 2,000 mg of omega-3 fatty acids per day. If you are taking 4 x 2,000 mg = 8,000 mg of omega-3’s daily, you are asking for trouble. In addition, if your dietary supplement is in the form of ethyl esters, there are more than 49,000 mandatory reported adverse events reported to the FDA.

    • Check your MTHFR, your test results indicate a possible polymorphism in this SNP.
      (Nutritional Medicine Practitioner/Herbalist)

  8. I’m a 79 year old male. I go to the gym daily and eat vegetarian (plus eggs). I have been taking 15 grams fish oil morning and 15 grams of fish oil evening for about 12 years now. people tell me I look about age 50. I attribute my youthful looks and smooth skin to my megadosing of fish oil for so many years.

  9. Hi Chris,
    Yu said: 1g/d of cod liver oils is outweighed by the benefits of the fat-soluble vitamins.

    What is the best way of measuring out such a small amount from a bottle of fish oil?

    Thanks, Alex

    • Alex,

      I do not know if you ever received an answer for this but the best way is to use a graduated eye dropper/medicine dropper available from any local drug store or pharmacy.


  10. Too bad it is not safe to eat fish twice a week nowadays due to mercury and arsenic contamination of most seafood products.

  11. I started taking a natural Omega 3 product from a North-European producer, which balances the Omega 6:3 ratio 3:1 or lower, thanks to which I would consider myself cured from the uncurable. As I sceptic I also use blood tests from a internationally certified independent laboratorie. This is a simple dry blood-spot test for home sample collection. The laboratorie analyze the sample to determine your fatty acid profile as a reflection of your diet. The balance test identifies levels of 11 fatty acids in the blood with 98% certainty. You will learn your blood levels of omega-3 and your ratio of omega 6:3 for balance, plus receive a report to increase your health and dietary awareness. Test results will show whether your diet is balanced or unbalanced.
    Finally, if you hold a ratio 3:1 or lower then all life style diseases (skin, joints, asthma, allergies, diabetes 2, high blood pressure, thyroid, osteoporosis, cardiovascular diseases etc.) will start disappearing.
    My first test ratio was 8,4:1 at 27-th of February 2013, second after four months 3,4:1 and third a year later 1,6:1 and I`m OK- my psoriatic arthritis and psoriasis diagnosis code was L40.0(-).

  12. Hi, my father in law who suffers from bi-polar and also alcoholism has just recently been taking fish oils in large quantities. At first it helped him with his pain & swelling however then he started taking them all the time.
    As of 2 days ago he has been omitted to hospital and today was placed in the mental Ward. The 3 days leading up to this he had taken 100 tablets or more. One of those large buckets. It reacted massively with his mental state and made him very alert as if he had been given amphetamines. He had no control of his thoughts.
    I am very worried he will not recover.
    Does anyone know a way of flushing these omegas from your body or have any suggestions that may help?
    Thanks in advance

  13. I was taking fish oil supplements starting at age 51 and 3 years later i had a heart attack. i was doing very hard work digging up glue off of concrete for about 45 mins. when this happened. So I’m not sure why this could have happened to me. I have always kept my weight normal and used to walk all the time for exercise. I am now struggling some days, dizzy, feel not so great. Also, started taking coq10 after that HA. And cayenne pepper 90 heat units which it says you will never have a heart attack. Any advice?

    • At age 51 I’d suggest that you look at your lineage. Genetics in early heart attack play a huge part. I have seen entire families when +/- 2 years every male had a heart attack in the family history. Look backwards and perhaps you can find something useful. Also consider smoking, a huge factor

  14. The slightest hint of fish oil supplement in my multivitamin and my joints are in so much pain I can’t walk, use my hands or use my back…. Takes days for it to wear out of my system to get back to normal.

    • Deborah:

      Check to see if the product you are taking is in the form of ethyl esters. These are typical side effects reported for those taking Lovaza (omega-3 acid ethyl esters) that is composed of 465 mg EPA-EE and 375 mg DHA-EE per softgel.. Can you share with us what product you are taking and I will see if someone has analyzed your brand? Someone has information at omega-3-acid-ethyl-esters.com.


      • I’ve been a 7 day a week gym rat for more than a decade. I’ve had my bouts with tendinitis and other injuries. I’ve never taken fish oil, though so many folks swear by it, I decided to start (with my mega foods 1 a day). Interestingly, I started to get terrible elbow pain shortly after I start taking it, with no explanation or change in workout… Rest didn’t help, nothing helped… I’ve now stopped the fishing for about 3 or 4 days now and miraculously, the pain is subsiding. Wondering if it can be contributed to the fishoil?

        • I have been experiencing this same problem! I started taking fish oils a couple months ago. My elbows became so inflamed my arms are going numb. So, I stopped taking them and it got better. Then, last week I thought I would try one more time. Same thing. I can hardly work without shaking my hands back awake and my back and feet are also aching. I thought I was losing my mind because fish oils are supposed to do the opposite. Glad to know I’m not alone 🙁

  15. I have been taking 1g of fish oil for over 20 years (this year algae oil). I have ADD and both these oils measurably improve my concentration, mood, anxiety, impulsiveness, knee pain, menstrual symptoms, skin and sleep. No other supplement has given the promised benefits that fish oil has. I hadn’t read a whole book cover to cover until I started taking fish oil in my 20’s, and I am unable to get through a paragraph within 10 days of going off the oil. Study or no study, I can’t function without the stuff. Too bad it seems to be causing me exercise induced chest pain in my 40’s despite excellent fitness. I don’t like hearing that omega 3 sources are either rancid or toxic but I would rather risk shortening my life span with toxicity (the entire food chain is toxic at this point) than stress about concentration related errors at work, impulse related errors in relationships and finances, limited exercise due to knee pain, poor sleep, older looking skin, many good books gone unread, not to mention killer cramps. The reason I’m impulsively and randomly blurting this expression out there is because I have tried to go off the oil for just about a week and once again I am sorely reminded I can’t live without that oil. If I was taking it, I would have had a second thought about impulsively babbling like this and stopped myself from sending it. Now I’m late, another thing the oil helps with.

    • I was googling about too much cod liver oil/ omega 3 oils. Why? My dad has been taking over the RDA for years due to arthritis and joint problems. He has always been super fit. He has lately been diagnosed with severe heart desease. This started with chest pain and respiratory problems. I could not understand how this could happen. No history of heart desease in the family. This is just speculation that there is a link but I can’t see any thing else. His diet had become poorer in older age eg moderate, chocolate, sugar, alcohol. However starting with cholesterol everything deteriorated with him doubling and tripling with the supplements. He never complained of arthritic aches and pain in 20 years since taking them but this news devastating! To the lady who can’t live without them. Check out that chest pain! It could be your heart!

    • Denise:
      I have ADD too and the fish oil also helps with depression. Can u recommend a brand? Is Whole Foods Cold water fish oil okay? One capsule is recc and it had 180mg EPA and 120mg DHA.
      I have no clue how many mg is good.I’ve looked it up on line and still don’t have an answer.
      I don’t want to overdo it at all.
      Thank you very much.

      • Hi Denise,
        I have never had a problem with Andrew Lessman’s Maximum Essential Omega-3 Ultra Concentrate Of DHA And EPA Free Of Mercury And Contaminants. I take a few of his products and have never had a problem. He is the Founder of ProCaps Labs and you can find his products at HSN.com. I also buy his products at Amazon.com. Every so often he is on HSN and gives good discounts and free shipping. Hope this helps.

  16. My sons liver enzymes. Are sky high. Wonder and hope is that he takes 3000 to 4000 mg of fish oil per day.. He is 6’6 and is 260 pounds. And Dr suggested 1000 mg per day but he takes so much more than recommended hoping it would help is cholesterol would be better…. Could too much fish oil effect his liver enzymes?

    • I was a medic in the army. When we would prescribe medication, it’s stressed that they take ONLY ONLY ONLY the prescribed dose. Positive effects of a medication or supplement can only go so high. After the maximum prescribed dose is breached, benefits stop growing, and instead, side effects become more prominent.

      Taking a whole bunch aspirin doesn’t make the pain go away better, it just thins your blood to the point of your body not being able to stop yourself bleeding.

    • Sorry to say but the thing that will definitely help your son is to lose some weight. Fish oil won’t help as much as a good diet and exercise program. How do I know this? Because I was also overweight and tried supplements and all that crap and it didn’t work as good as losing that extra fat.

    • Yes, it can. My liver enzymes were also high when I was taking cod liver oil. That was the only possible explanation, they were never high before. I thought maybe it was the high vitamin A content that caused it because overdosing on vitamin A can raise liver enzymes.. They went back to normal once I stopped.

  17. You recommend 1g/d of cod liver oil, that is 1/5 of a teaspoon. Is it that you meant no more than 1 g/d of omega 3 fatty acids from cod liver oil? My cod liver oil bottle states it contains 1.4 g omega 3 fatty acids in 1 teaspoon of cod liver oil.

  18. How can you in good conscience make the claim that ” The only trial lasting more than four years, the DART 2 trial, showed that fish oil capsules actually increase the risk of heart disease and sudden death”

    The study clearly concluded that the increased association could have been due to a number of factors, including overcompensating or previous at-risk behavior. There is no causation whatsoever in this study, and your claim that fish oil capsules INCREASE the risk of heart disease and sudden death is a departure from your normally thoughtful analysis.

    • I agree. Chris’s article comes across as being biased to me. One of the issues Chris highlights is that fish oil easily oxidises, but there’s a simple remedy for that: buy fish oil which contains added Vitamin E (or other antioxidant) to stop it oxidising. Pharmaceutical grade fish oils usually come with antioxidants in them anyway.

      • I buy from Omega 3 innovations. I’ve heard the only issue with omega 3 oil is oxidation making it rancid which can cause adverse effects instead of being benificial. Peroxide level 0.10, anisidine level 1.60, these are important! Read up on this at http://www.omega3innovations.com.

  19. Not sure how old this article is. Just wanted to add that if you are taking fish oil then you should be taking Vitamin E with it. Taking fish oil long-term can cause a Vitamin E deficiency, which brings with it, many new problems. Many parents are giving their children fish oil hoping it will improve their ADD, autism, apraxia, etc. not realizing that fish oil can cause vitamin E deficiency and many of these children are already deficient in vitamin E to begin with. Also see Dr. Claudia Morris’ video regarding vitamin E and apraxia and autism.

      • Also we should not be using the term “fish oil”. The term “fish oil” is actually meaningless, considering the difference between the grades of fish oil available, for example, health food grade fish oil, and pharmaceutical grade. Pharmaceutical grade fish oil is much safer and can be taken in higher doses. Also, fish oil can cause a vitamin E deficiency in adults, after a decade or more. In children, however, this vitamin E deficiency can occur very quickly, especially when using a health food grade or rancid fish oil. People are buying jumbo health food grade fish oil for their one year olds hoping to cure autism, only adding to the oxidative stress to their child’s body. Any Omega 3 oil can have this effect, even hemp and flax oil. This can lead to ataxia, apraxia, eye twitches, and hemoblastic anemia.

        • There are some brands that have Vitamin E added into the fish oil as a natural preservative. Interesting that it’s also providing additional benefit. I’ll make sure to continue to use brands that add it in! Thanks!

    • Take a look at Life Extension article on fish oil Sept 2012 Take a look at Organic Facts. Accoring to the American Heart Association clinical trials have shown a decrease in cardiovascular disease by taking fish oil. It can reduce arherosclerosis as well. It reduces inflammation.

      There are several studies that show fish oil is beneficial. The Mayol Clinic recommends fish oil.

    • By Dr. Mercola

      Omega-3 rich fish oil is one of the most well-researched nutrients on the market. Its wide ranging health benefits have been repeatedly proven, and animal-based omega-3 fats are one of the few supplements I recommend for virtually everyone to improve overall health.

      It’s particularly critical for your brain health, and as the featured article and my interview with JJ Virgin shows, it may even help heal and restore brain function after a traumatic brain injury. Recent research also suggests that fish oil can help slow down age-related brain atrophy.

      According to the Centers for Disease Control and Prevention (CDC), some 1.7 million traumatic brain injuries occur in the US each year, making the prospect of utilizing fish oil very exciting. It’s inexpensive, and although it does act as a blood thinner, which could be contraindicated in some instances, its side effects are virtually all beneficial.

      According to leading omega-3 expert Dr. Barry Sears, there are currently seven cases in the medical literature describing the use of fish oil for traumatic brain injury—each one of them successfully so.

      16-Year-Old Defies Death Following Fish Oil Treatment

      The featured CNN article describes the tragedy and triumph of 16-year-old Grant Virgin, who suffered a wide range of injuries in a hit-and-run car accident. His injuries included skull fractures, spinal fractures, and bleeding throughout his brain. Doctors didn’t give his parents any hope for recovery. Instead of shrugging their shoulders in acceptance, his parents were indignant.

      “It’s like, how dare you not fight for my son’s life?’ said JJ Virgin.

      ‘It really took us… getting very aggressive and assertive to save our son’s life, because they weren’t going to do it… They told us to let him go,'” his mother told CNN.1

      From that moment forward — time and time again — they would go against doctor’s orders. That included trying unconventional, untested therapies — anything that might help Grant. One in particular involved giving him high doses of omega-3 fatty acids (found in fish oil). Fish oil is what the Virgin family believes ultimately — dramatically — altered his life course, and healed his brain.

      The Virgin family learned about fish oil from friends who had caught a previous CNN report about fish oil being used in cases of severe brain trauma. Grant’s mother, JJ Virgin, tracked down Dr. Barry Sears who, in 2006, consulted on the case of Randal McCloy—a miner who had suffered brain injuries from carbon monoxide.

      In that case, which was the first time fish oil entered the medical literature as a treatment for brain trauma, it was McCloy’s neurosurgeon who called on Dr. Sears’ expertise in a last-ditch effort to rescue his patient. As reported in the featured article:

      “‘There is no known solution, there’s no known drug, there’s nothing that we have really to offer these sorts of patients,’ said Bailes, co-director of NorthShore Neurological Institute in Evanston, Illinois, during a previous interview…

      The theory behind fish oil as a therapeutic intervention for traumatic brain injury is at once simple and complex. Simply stated, the brain’s cell wall is, in part, composed of omega-3 fatty acids.

      ‘If you have a brick wall and it gets damaged, wouldn’t you want to use bricks to repair it?’ said Dr. Michael Lewis, founder of the Brain Health Education and Research Institute. ‘By supplementing using (omega-3 fatty acids) in substantial doses, you provide the foundation for the brain to repair itself.'”

      Fish Oil—A Potent Anti-Inflammatory

      Omega-3 fats, which help fight inflammation throughout your body, also helps quell inflammation in your brain. After a traumatic injury, the brain inflammation that occurs can continue for long periods of time unless, as Dr. Sears states, “there’s a second response that turns it off.”

      Fish oil, it appears, can help do just that, when given in sufficiently high doses. After spending nine weeks in acute care, Grant was transferred into a rehabilitation hospital where he began receiving 20 grams of fish oil a day. (His parents had reportedly been sneaking fish oil to him while he was still in emergency care, but not at that high a dosage). Two days later, his mother received a late-night phone call from her son.

      “Forty-eight hours after receiving high-dose fish oil, Grant Virgin asked a nurse for a cell phone to call his mother, and proceeded to have a conversation with her. ‘Unbelievable,’ she said. ‘Unbelievable.’ Unbelievable, especially considering that was only two months after Grant Virgin’s parents had been told to ‘let him go,'” CNN writes.

      • How much fish oil-EPA/DHA is a recommended dosage? There are so many articles and my Dr. seems to think Fish Oil is a waste of money. Please let me know what you think. I am currently taking 1300mg of EPA and 850mg of DHA daily in one tsp. of concentrated fish oil equaling 4500mg. Thank you, Tracy

    • AS WE SEE IT
      How Much Fish Oil Is in Your Blood?
      By William Faloon
      By William Faloon

      William Faloon
      Evidence supporting the benefits of omega-3 fatty acids is so convincing that fish oil is the only dietary supplement the American Heart Association recommends people consider taking.1-3

      The American Heart Association has a longstanding bias against dietary supplements. So when they publish about the importance of consuming omega-3s from fish or supplements, this is a ringing endorsement from an otherwise slow-to-react scientific organization.

      Both the Life Extension Foundation and American Heart Association recommend omega-3 fats based on the published literature showing that those who consume cold-water fish or fish oil supplements have markedly reduced rates of heart attack and stroke. While these studies present persuasive data, a missing piece of the puzzle is how much EPA and DHA is required in the blood to protect against coronary artery disease.

      Measuring EPA/DHA in Heart Attack Victims’ Blood
      A landmark study was recently published on 1,059 patients admitted to the hospital because of heart attack or unstable angina (chest pain from coronary artery occlusion).4 Blood samples taken from each of these patients were evaluated for conventional cardiac risk factors and also EPA/DHA content.

      Compared to age-matched controls, the risk of unstable angina or heart attack was reduced by an astounding 62% for every 1.24% increase in whole-blood EPA/DHA. As the chart on this page clearly shows, the risk of having a serious cardiac event plummets as blood levels of EPA/DHA increase.

      This image depicts daggers aimed at a healthy heart. Any one of these daggers would kill if thrust deep into the heart. In the real world, however, aging humans suffer small pricks from the point of many of these daggers over a lifetime. Although none of the pricks by itself is enough to cause a heart attack, the cumulative effect of these dagger pricks (risk factors) is arterial occlusion and, far too often, angina or acute heart attack.
      Low Blood EPA/DHA: New Independent Cardiac Risk Factor
      When blood levels of EPA/DHA in these cardiac patients were matched against a control group, statistical analysis was able to show that low blood levels of EPA/DHA may be a new independent cardiac disease risk factor, at least in middle-aged patients.

      In this scenario, an “independent risk factor” means that even if other known promoters of coronary artery disease—such as cholesterol, LDL, and triglycerides—are in normal ranges, one’s risk of suffering a cardiac disease is still increased if blood levels of EPA/DHA are below the optimal range.

      In discussing the information gleaned from the study, the doctors noted that it supported earlier research published in the New England Journal of Medicine in 2002, showing lower blood levels of EPA/DHA in people who died suddenly from a heart attack, compared to controls.5

      Figure 1. Rate of Heart Attack and Unstable Angina Sharply Decreases as Blood Level of EPA and DHA Increases.
      Guarding Against All Known Promoters of Coronary Atherosclerosis
      Despite greater awareness of cardiac risk factors, heart attack is still the number-one killer of men and women.6 Sadly, heart disease and stroke are largely preventable, if people only had their blood tested and took the appropriate actions when proven cardiac risk factors fall out of optimal ranges.

      Few physicians understand that coronary artery occlusion can result from any combination of 14 different causes. While protecting against some of the underlying causes may delay its manifestation, heart disease will strike a large segment of the aging population that does not take corrective actions ahead of time.

      The good news is that most underlying causes of coronary artery occlusion can be detected by comprehensive blood tests.

      Based on the new finding that low blood levels of EPA/DHA may be an independent cardiac risk factor, we are adding “Low Blood EPA/DHA” to our evolving graphic of lethal daggers pointed at the aging heart. We are also factoring in the voluminous data showing that those who consume EPA/DHA in fish or supplements have significantly reduced coronary disease incidence.7-15

      The vivid graphic on page six makes it clear that aging coronary arteries are vulnerable to occlusion from a variety of insults. Based on these findings, it is difficult to comprehend why anyone over the age of 40 would not have their blood tested once a year to find out if their coronary arteries may be silently occluding (narrowing).

      Control Your Own Cardiac Destiny
      The annual blood tests recommended by the Life Extension Foundation are available at your doctor’s office, in hospitals, and through commercial testing laboratories.

      The most convenient way of obtaining the proper tests is to take advantage of the low prices offered by Life Extension’s nationwide blood-testing service.

      Just one phone call to 1-800-208-3444 enables an order to be placed for the comprehensive Male or Female Panel. Members are sent a computer-generated receipt that they take to a blood-drawing station that is often in their own neighborhood.

      No appointment is necessary. This means that members can pick a convenient time to have their blood drawn. The test results are usually mailed within 10 days. If there are any questions, Life Extension’s health advisors are available to answer them.

      Each year at this time, we reduce our everyday low prices. Until May 31, 2007, we discount all blood tests so that members can obtain comprehensive blood evaluations at a fraction of the price charged by commercial laboratories. For example, members save as much as 80% on the Male or Female Panels compared to what commercial laboratories charge.

      If this editorial saves just one life by detecting a cardiac risk factor in time, then it was well worth publishing. Based on the number of Life Extension members who are now having their blood checked, I am convinced our message is helping to extend the healthy life span of many human beings.

  20. “there is no evidence that people other than those with arrhythmia and chronic heart failure benefit from taking fish oil or that doses higher than one gram of omega-3 fatty acids per day provide any benefit over smaller doses. And then there’s the rather disturbing result of the DART-2 trial, the only fish oil study lasting more than four years, showing an increase in heart disease and sudden death.”

    My grandfather died age 56, whilst curling, from arrhythmia (his parents lived to 96 & 97). I believe the cause was diet having re-married, after first wife died—and new wife had a deplorable diet and died 22 years later at age 55 of brain cancer.

    The answer to arrhythmia may be magnesium, which must be constantly consumed as it is only stored in the small intestines and needs constant replenishment. Once magnesium is used up the electro-system immediately shuts down. There is no wiggle room when the Great Electrolyte Regulator is concerned.

    Three of my younger brothers have heart troubles, I am the second eldest and have no such problems having taken magnesium regularly throughout the day since 1974. My mum suffered potassium deficiency three times in 1974 and had to be rushed by ambulance to hospital. Upon research over six months I discovered the fact that magnesium is the great regulator and the consequences of its depletion. Mum died in hospital twenty years later when being assessed for independent living in the same hospital (an apartment setting for such assessment) but was not allowed to administer her own pills and was not allowed to bring her supplement of Magnesium with her. She died the third day of assessment from sudden electrolyte stress. Her two younger sisters died of the same deficiency years before, even though we had both warned them of the need for constant magnesium.
    Namaste and care,

  21. I’ve been studying Health/Nutrition for more than 30 years and pride myself on staying “current.” Again and again, however, it seems a case of, “Just when you thought it was safe to go back in the water…”

    I gave up krill (another highly touted oil) after learning about Fermented Cod Liver Oil on the WAPF site and have been using the FCLO exclusively for about a year and a half. Now I’m reading contradictory reports on this source as well (despite the long history of cod liver oil use, sans the fermented element). Questions have come up about how exactly is fermentation carried out when fish contains no sugars/starches–is the fish just left in vats to, well, rot? Not a pretty picture. Then I read about the use of lactic acid for the process, which makes sense, but for me, controversy such as this just puts me on edge.

    The problem is that I’m still not sure whether to take the FCLO, anticipating some future “oops,” about this supplement as well. The more I learn about most supplements, the more I am convinced (especially as a Paleo person) that our nutrition should come primarily from whole foods (as with native populations referenced here) where the full power and safety of the “isolated” nutrient is most assuredly dependent upon the synergistic effects of its “mother” — “the whole,” as they say, “is greater than the sum of its parts.”

    How so many of my relatives made it into their late 90s and even 100s by just eating regular old foods simply escapes me. Perhaps it was the lack of stress resulting from the relentless onslaught of “eat this/no! don’t eat this — take this, wait no, it can kill you…”

    • Hi Maggie! I love what you’ve said, and I couldn’t agree more with you. Thank you for sharing your insight and wisdom here- what a great conversation topic. I’m awaiting comments from Chris, as I am sure we all are.

      Do you have a blog? Could you share what it is, if so?

      Stacey Rae

      • Hi Stacey Rae!

        Thank you for your kind words; I’m happy to see you agree. I’ve been advising friends and family (some might say ‘preaching,’) for years on steps to eating healthier (it’s gotten so that I have to avoid looking in shoppers’ grocery carts unless I’m at WF Market); most just spout out the familiar, deeply entrenched argument: “What’s the point? Everything gives you cancer anyway!” or, “Hey, you can’t live forever.” I try to get the point across that of course I know I can’t live forever, but that I for sure don’t want to be “dead” while I’m still alive!

        There is one friend of 13 years (male) I’ve managed to wear down, and he’s slowly but surely coming over to my side in some respects, although of course there are foods he’s just not about to give up; but, he, too gets frustrated when I catch him up on the “latest” studies that show this or that, some of which no longer show the same “this or that,” and I tell him that many study results have remained as constant as gravity and that this is why we have to align ourselves with the scientific method, with what evolution has taught us about who and what we are rather than blindly following the herd mentality that sprung from the not-so-scientific methods during the reign of Ancel Keys, et al.

        It sometimes seems easier for folks to reconsider their religious or political beliefs than it is for them to reconsider their nutritional ones .

    • Supplementation is never to first option. The right foods are the most important and even healthy foods can be harmful in large quantities. We promote the health benefits of eating fish. But too much fish can be toxic. We hope people understand the following two concepts:

      Don’t supplement if you can eat healthy foods.
      Also healthy foods can be dangerous if you exaggerate.

  22. Thanks for that thoughtful article. I just want to run this by you Chris:
    A well known lecturer and assistant professor in nutrition (who I won’t name here) at an American university explained to me at a recent workshop he was running here in the UK that he takes 25-30 grams daily of omega 3 fish oils! I was astounded. He does this because he had multiple autoimmune diseases inc Crohn’s and ulcerative colitis and joint disease diagnosed in his early 20s, which is what lead him to train in nutrition science. On this regime his IBD is fine and he can even eat a croissant when in Paris without a bowel flare up! This too surprised me but I guess just one croissant in a healed gut might not bring about sufficient fresh damage to become symptomatic. I don’t know if the fish oil he takes is EPA or DHA dominant, as I didn’t ask him. This chap is 37, very fit, very buff, very bright and with apparently boundless energy, and I think he has been on a very high dose of fish oils for some years. Your comments please!

  23. Would it be best to just take krill oil as that has natural antioxidant which supposedly counteracts the oxidation problem? be glad to hear peoples thoughts. thanks

    • In our opinion supplementation is never the first option. The right foods are the most important and even healthy foods can be harmful in large quantities. We promote the health benefits of eating fish. But too much fish can be toxic. We hope people understand the following two concepts:

      Don’t supplement if you can eat healthy foods
      Also healthy foods can be dangerous if you exaggerate.

  24. Oh lord, everything is bad for us! Can’t have juicers because of the sugar ,can’t have 8 glasses of water cos too much is bad for you and just dilutes urine, now we can’t have cod liver oil. I wish health “experts” would make up their minds whether something is or isn’t good for us to have. I’m so fed up of double standard studies on everything! Maybe we should just give up eating and drinking anything since it’s all bad for us. I mean if everything thats bad for us, is being told to us that is is good for us , then the companies need to come forward and tell us. But no they won’t because they love taking our money from us by telling us we need this that and the other.

  25. Three weeks ago I suffered a life threatening subacute subdural hematoma (brain hemorrhage) with a craniotomy required to drain the bleed and relieve pressure on the brain. It started with a fall in December, the admission CT showed three bleeds, one in December, one in January and the one that felled me in February. The surgeons at the hospital blame fish oil for my problem. I was on two 1000mg capsules per day for my psoriatic arthritis, one in the morning and one in the evening. Fish oil is an anti coagulant and blood thinner. Had I not been on fish oil the surgeons say the first bleed would have been a non-event, bleeding would have stopped naturally and been re-absorbed with me never knowing about it. Instead the bleeding steadily increased in severity over about 6 weeks. The surgeons in the Neurology ward told me that approximately 25% of brain hemorrhages they see are fish oil related and they are seeing people as young as 30 due to fish oil effects. I find these statistics staggering. The doctors have instructed me to stay off fish oil for life.

    I really wonder why these reports seem to suppressed, all we seem to see is glowing marketing hype for the benefits if fish oil and nothing of the possible negatives. Even a Google search will find little on side effects. I can only speculate on the reasons why.

    • Thank you for sharing that information. After a traumatic brain injury in my car last year, with no hematoma, but much brain swelling and heat, and an infection, I have been wondering why the area hasn’t healed faster. I take two triple strength fish oil caps a day, but I think I should stop after reading your experience. Concussions are common, but we don’t want to make things worse for ourselves.

      • Hi Lightfoot, I just want to suggest that you take coconut oil as it provides ketones which are brain/neuro protective in all traumatic brain injuries. Sapolsky say: “ketones are neuroprotective and don’t let the surgeons give you steroids as they make things worse”.

    • Wow, I hope you are doing well and that is a pretty shocking testimony. They should definitely look into this. The only time I have heard of this is with excessive dosage. It sounds like you are taking a normal amount, but possibly the others weren’t? Hence the need for some kind of controlled study.
      Are you eating an otherwise low fat diet which would make the omega-3 more concentrated? I can’t think of why else 2 gm of standard strength fish oil would cause this from what I have read previously! (they were standard strength I presume?)

      • Having had a cat with a nasal tumor that bled almost continuously, I find myself wondering what else you may have been taking that thins the blood…I mean nutrients. Several things I wanted to give Penelope to fight the cancer or reduce inflammation also thin the blood! It was frustrating, curcumen, flax oil, artemisinin come to mind, but there were others. I would google “Does so and so cause thinning of the blood” and find that several others had asked that question and that it did indeed cause thinning of the blood. I was thankful for Yunnan Baiyao!

    • And if you had been eating dandelion petals probably the docs would have said: “Ah…that was the cause.” I’m not being overly cynical either having spent time as an Adult ICU RN.s

      I say look to pubmed, nih, and research true peer reviewed documentation before making decisions.

      There is a good study on the effects of ethyl esters of omega 3 on rats genetically pre-determined to develop and die an early death due to systemic lupus. The amount fed was a % of food intake and would represent a lot of lovaza equivalent. There was a very significant increase in life-span of the rats fed the large amount of omega 3’s.

      But the rats were never queried about significant adverse effects, so where are we? For adverse effects check factmed.com. It is rarely conclusive but often gives insight.

  26. I have spent days and countless hours reading your posts and listening to your podcasts. I love your evidence-based approach and your accessible style.

    One request: I wish you would put dates on your articles, especially because of situations where your thinking on a subject like fish oils might evolve over time (e.g. Taking cod liver oil regularly vs. limiting it to times of need). It would be helpful to see the chronology of your thinking.

    • I’m so glad you brought that up; that’s the first thing I questioned when I began reading Chris’s article (I’m a big fan). It’s not just Chris who neglects to include dates–I find this to be very common and very frustrating since, naturally, we want to be sure that we’re receiving current, relevant information.

  27. This is a distressing development for me. I suffer from a nasty condition (Sjogren’s) that requires me to take 5-6 grams of fish oil per day. If I replace this supplementation with eating fresh salmon, I start ripping my corneas within a week or so. I already buy IFOS oil, keep it in the fridge…is there something else I can do to protect myself? I don’t seem to have another treatment option for my dry eyes.

    • Hi Beedee,

      I am not commenting with any clinical authority just a health and fitness enthusiast studying a science degree and focussing on nutrition.
      I have listened to and read some things by dr Rhonda Patrick (worth looking up) and she, as well as others advocates the consumption of vitamin E (be this from other whole foods: seeds or nuts or via supplementation) alongside the fish oil supplementation.
      Vitamin E reduces or protects against some of the inflammatory effects of the oxidation associated with fish oil supplementation as detailed above.

      I appreciate this hasn’t been grounded in much empiricism I was just browsing on my phone in a break and wanted to try and help. I hope my comments can serve as a platform for your own research or for others to assist. Either way I hope I’ve been helpful.


    • hi beedee,

      I too have sjogrens and take around 3,000 mg daily to battle dry eyes. Do you take salagen? I take it and it also helps.

      • Hi, sorry to know you have dry eyes. It’s an irritating problem! I’ve relieved this problem by taking eye lutein that my friends have helped me bought from korea. You might wish to get it too since it works and is sold at affordable pricing. No idea if it’s available in your area. Let me know if u need help getting it.

    • Restasis has helped me SO much with my Sjogrens. I don’t know where I’d be without it! It takes about 4 months to work, but you will most probably notice a major difference!

  28. USANA actually have good quality of supplements such as ATP,
    Am’ I wrong ?
    Nutri-search is a good reference about supplements, right ?
    ATP is available since 2011 so they’re still not in the nutri-search guide.
    – sorry for my english –

  29. OmegaRx is the purest fish oil product you can buy with or without a prescription. It is free of heavy metals, such as mercury, and Zone Labs analyzes every lot to make sure the PCB levels meet the strict standards of Dr. Barry Sears. If you want purity and potency at the lowest possible price, then OmegaRx® should be your only choice.

  30. I do agree generally with your article, however the recent results showing a fairly, actually very significant positive affect of fish oil on Alzheimer’s disease may trump everything.

    • Urgent: I’m having a real problem with conflicting information on this site. The article “The definitive fish oil buyer’s guide” strongly endorses quality fish oil as a supplement. But the article “When it comes to fish oil, more is not better” contains dire warnings about the dangers of fish oil (except fermented cod liver oil). To have two drastically conflicting “expert recommendations” there for everyone to read seems like a real disservice at best & negligent at worst. Mr. Kresser, PLEASE clarify.

      • Yes, same here. I started taking 3g of Omega 3 from Nutrigold and Jarrows’s based on Chris’s previous recommendations (he used to say that it’s all about the ratio of 3 to 6, and take more 3 if you want a better ratio). Now he is stating almost the opposite – all of a sudden we are supposed to consume 3 and 6 (as in the FSLO supplements, which also comes with high dosage of proinflammatory vitamin A). What do we do??

      • I’ve made this request twice – for clarification on the fact that one posted article here tells us fish oil is highly beneficial and a second article that says it just might kill you. Several other people have echoed this. I’m astounded that there has been no response & the drastically conflicting information is still posted. I am ceasing to come to this site as of today & am recommending to all my all online contacts interested in nutrition that they do the same. A real disservice, Mr. Kresser – shame on you.

        • David,
          After re-reading Chris’s alarmist post and then looking over the studies he references, I am in full agreement with what you have posted. I, too, will continue to look to more trusted sources which are not replete with contradictory, inconsistent and incomplete information. I have taken issue overall with some of Chris’s prior advice/recommendations based on, for example, conflicting yet concurring information among other reputable health researchers.

          The studies Chris cites raise more questions than confidence in their conclusions. It’s not simply their conclusions that seem questionable but also their methods and implementation. I was particularly bothered by the study which surrounded its analysis based on cholesterol values. It is becoming increasingly recognized that years of warnings surrounding the “dangers” of particular cholesterol levels are unfounded and, to a great degree, amount to little more than myth. In fact, one excellent eye-opening expose which I have just completed and recommend is The Great Cholesterol Myth: Why Lowering Your Cholesterol Won’t Prevent Heart Disease-and the Statin-Free Plan That Will by Drs. Jonny Bowden and Stephen Sinatra, highly known and respected in their fields (nutrition and cardiology respectively).

          We Americans need to “take back” our health!

        • Agree. I’ll bet the website that sells his services and products are kept up to date. It’s a shame that he nor any of his administrative staff have responded to your questions.
          Chris has become famous and has forgotten the people who got him there. I quit my email subscription and will no longer visit his site.
          To leave conflicting undated and not updated information on the web, is pretty sad, given the whole purpose is of these articles is to promote health. Shameful.

          • Yup! I’m outta here too–far more reliable sources out there! Too bad, yet all of us should exercise doubt, practice skepticism when we feel it in our gut, take the word of “experts” as perhaps fleeting (always Question Authority)–and most importantly, do our own thorough research and then do some more. One life…

  31. Hi Dr Chris,
    I have read many articles in the recent couple years that agreed with you on not taking fish oils. I have looked into another source and would like your thoughts please… How do you feel about “Nordic Naturals Algae Omega”? Personally I would prefer NOT to take any fish oils regardless of the FCLO you suggest.
    Also, do you have a recommendation for a DHEA supplement that you particularly like?
    Hear from you soon,
    Thanks so much.

  32. I am trying to figure out why I have had constant, and I do mean constant diarrhea for the past several months. Have spend thousands of dollars (insurance has anyway) and still no answers. I came across an article that to much fish oil can cause it. I started taking the LLV from doTerra several months ago and never put it together. Do you think this could be the cause?

    • Pam,
      I feel for you, having had severe diarrhea for about two years before someone thought to give me a blood test for Celiac disease. It was positive to the extreme. By this time I was so weak and had lost all muscle tone. Back to you – until you get a diagnosis, consider getting a blood test for Celiac disease, and after you have that, please give the gluten-free diet a trial with no cheating, for a good three months at least to see if that helps. Meanwhile, are you drinking electrolytes to replenish those lost with d.? And keep eating enough high quality protein, as you are losing so many nutrients every day. You can certainly eliminate anything you suspect as a cause, and just keep searching – parasites, gluten and severe food allergies seem the most logical places to start. Don’t just wait for your doctor to suggest something, as his interest in your case has human limitations. Do your research and definitely try the gluten-free diet only after the Ttg test (you have to be on gluten for it to work).

    • Yes indeed. Fish oil gave me diarrhea. The combination of my capsules plus my daily magnesium was a recipe for disaster. The gluten police will tell you to go gluten free but try eliminating supplements before cutting out entire food groups.

      • Nofish it’s the magnesium that is probably given you diarrhea. If you ate taking citrate or oxide version that’s why you have problem

        Switch to Chelated magnesium

          • Hi No Fish – Just jumping in here to help you in case you didn’t get a reply. Natural Calm reacts with water to create magnesium citrate is that is highly stimulating to bowels. I only recommend that form to my clients who have constipation. I agree it’s highly likely that the mag is a key component of your loose stools. I recommend magnesium glycinate or malate for those with normal/loose stools. However, it is also true that you may have fat malabsorption in your intestines. I have seen this often when there is a parasite or an imbalance (dysbiosis) in the bacterial balance in the intestines. However, in this latter situation, it wouldn’t be only the fish oil giving you loose stools but rather any intense intake of fat at once. Thus you can easily experiment to find your true root cause. But certainly I agree: the Natural Calm is probably the larger culprit. Hope that helps!

      • That’s the combination I’m on magnesium and just introduced fish oil. I feel dreadful!! Diarrhoea, nausea and feel very lousy!

  33. I’m confused. The article “The definitive fish oil buyer’s guide,” seems to strongly endorse quality fish oil as a supplement. But the article “When it comes to fish oil, more is not better,” contains dire warnings about the dangers of fish oil (except forced liver oil). Can anyone clarify this for me?

    • I have the same question as David. I just read the Definitive Fish Oil Buyer’s Guide a few days ago and this seems to contradict that info. Chris, can you clarify. Is this the latest? How old is the Fish Oil Buyer’s Guide on your website?

      I use quality fish oil products for my son with epilepsy and for his Service Dog as well.

  34. The quality of the fish oil supplements used in research could vary considerably, was that controlled? If researchers got their fish oil supplements off the drugstore shelf, I’m not surprised that rancid, oxidized fish oil that wasn’t molecularly distilled would show an increase in risk of disease.
    Granted you’re saying it oxidizes in the body, hence the risk, but do we know if a high quality fish oil supplement poses the same risks as an oxidized, rancid oil?

    • Only use liquid fish oil , not softgel capsules

      Fish becomes rancid when it is heated in the softgel. That’s why they add lemon to mask burps.

      Best is Carlson Fish Oil or Carlson Cod Liver but only in liquid form

  35. Hi Chris,
    Just started taking fish oil. Have a pretty significant depression going and trying different means to help myself. Taking EPA, about 4000mg /day split into two times each day and taking it with 12 g of extra v olive oil each time. Do I have this wrong? I know your preference is the fish, not the fish oil. I intend to do that as well. Thank you very much

    • Hi, for depression personally i recommend a combined approach. Eliminate grains and sugar, increase protein and increase fat (eggs for breakfast every day is a great start ) also look at a paleo low carb approach. There is some evidence that a ketogenic diet has a positive effect on depression (as long as it meets your nutrient needs and is well planned ) i have used this approach for several people and it seems to work quite well. Individual results and reasons for depression vary a lot though!

      Cheers, Tim

    • For significant depression, you must see a doctor first and foremost to get treated so that you are stable. and only then try nutrition to augment your meds. Mild and moderate depression can respond to amino acids like 5-HTP or tryptophan, but it sounds like yours is real suffering and can cause one to be suicidal. Brain imbalances must be treated by a professional. Even then, it can take several different prescriptions till one feels normal and happy again.
      All the fish oil in the world won’t balance brain chemicals. Going off all gluten grains is a good idea, as Celiac disease can cause depression, but please see a doctor.

      • Listen to Jeanne’s advice only if you want to prolong your suffering or make it multitudes worse. Take it from someone who’s been on multiple prescription depression meds as well as plenty of other prescriptions. These prescribed meds generally lead to greater mood swings than you would have ever seen normally. A natural dietary option is your best bet for leading to a sustained improvement in overall cognitive functioning. Something else that nobody seems to ever mention (because the pharmaceutical company buries the information) is Neurofeedback. Check out Low Energy Neural Stimulation (LENS) treatment, as it has an extremely high rate of success of eliminating (or at least limiting) cognitive deficiencies. Also, if you’ve had a concussion throughout your life, that may have brought on the issues you’re experiencing now and neurofeedback can also work with the brain to repair neural pathways. Hope this helps, and wishing you a swift recovery! Best, Parker S.

        • I’m happy for anyone that can treat their depression naturally. After trying this route first with one friend, who was severely depressed, I had to make an emergency appointment for her to a doctor so that she wouldn’t harm herself. This same young woman before her episode had spent three weeks with her own friend who was so unstable she was trying to commit suicide and needed someone to stay with her night and day for three weeks while she worked with a specialist to get balanced again. She had tried everything before this, self-medicating. Some people need help to become stable. The suicidal woman is now happily married and still needs meds, but the other woman doesn’t need anything anymore and weened herself off everything. Don’t think I want people to take drugs if they can possibly manage without. Most people don’t need them.

          • I agree with Jeanne. Being a person who had been through prenatal depression myself, best bet would be to get a proper diagnosis from a doctor, stabilize the situation before having any other self medications. Please do not treat depression lightly as it can be life threatening.

  36. Thank you for putting together an eloquent summary of a controversial, yet an important subject matter.
    The first rule in medicine is “first do no harm”. Unfortunately, our peers in natural medicine have supported the (potentially dangerous) use of fish oil with no rel debate.

    • You mean, the article that got retracted for being complete BS? That article? I guess that’s one way to support your argument. LOL

      • “The article titled “Why Fish Oil Fails: A Comprehensive 21st Century Lipids-Based Physiologic Analysis” [1], published in Journal of Lipids has been retracted as a result of an undeclared competing interest on the part of the manuscript’s author.”

        What does this mean?
        I suspect that Professor Peskin was selling or linking to sales, on his site, of PEOs which he is no longer doing.
        That does not discrete his work but it is against the regulations of the publishing site.

        I could be wrong on this but the description is not terribly detailed to the problem.

        Your addition “LOL” shows your bias and very possibly closed mind.
        Namaste and care (and keep safe in your beliefs)

  37. I’m a vegetarian and I don’t eat fish. I made an exception for fish oil capsules because I believe Omega 3s are important. However I have found that I cannot tolerate the capsules as they give me bowel issues. Is there another way to get Omega 3s? I can’t take flaxseed oil because of breast cancer concerns.

      • Mr/Ms Sharp: the foods you named are such miniscule soures of omega 3 you’d have to eat bushels of them to even get the lowest dose any doctor recommends. This is one of those vegan fallacies, that the foods you named provide any more than a slight trace of omega 3s.

  38. Chris,

    Your solution and direction is for all people to eat 2-3 servings of fatty fish a week? O.k.~ Where are we going to get all these fish from? If “everyone” did this… we’d have no fish left. The oceans and reefs are in a dire state now. How can you recommend something that, even though it may seem like good advice, is not really practical or sustainable?

    • Hi Jen,

      I don’t think it’s sustainable for human beings to have to limit essential nutrition either, nor do I think it’s necessary to solve the problem. Polluting waters and not fishing in a way that allows for populations to thrive is what limits their numbers. Solutions don’t manifest from a place of scarcity consciousness. There’s tremendous intelligence in the world, take Allen Savory, for instance. He challenges conventional ideas about the cause of global warming and understands how to create a thriving ecosystem where every living organism, including people, can thrive.

  39. I read that fish oil helps people with salicylate sensitivity. Will the fermented cod liver oil help with that? If so how much per day? Thanks!

  40. Hi Chris,,
    Very late to the discussion but I wanted to comment on your conclusions from the Saito journal article re peroxidation in rats fed high doses of DHA, EPA, ALA. Their conclusions were, “the extent of lipid peroxidation in the EPA and
    DHA groups fed diets with adequate level of vitamin E was
    far less than expected from the relative peroxidizability
    indices of the total liver lipids.” That seems counter to what you concluded from the article, yes?

  41. I was very interested to read what you have written about fish oil supplements. Normally I take a 1000mg Fish Oil capsule daily and recently upped that dose to two per day (taken together). I have recently also noticed a few joint sensitivities in a couple of fingers which I have never had problems with before. I have just started cutting out the fish oil so will be interested to see if the problem goes away. In my diet I have oily fish about twice a week plus chia seeds every day (I believe they have a good dose of Omega 3), so hopefully that is all I need as I am normally very healthy. I hope this is of interest to you. Thanks, Janice

  42. I am sticking with fresh caught salmon for now. I just discovered camelina oil sold by a Washington company that grows and cold presses it. It is 33 to 40% omega 3, 20% omega 6, with olive oil at 10% omega 6 and 3% omega 3. I am wondering about the DHA percentage content. Burn point 475 F.

    Link on some testing of this plant and its seed for omega 3 content:


  43. Thanks for the article Chris, I had been taking 1000mg krill oil per day for the past year and everything was fine with my health, however in May 2014 i changed to fish oil and started taking 3000 mg per day, In June i started noticing a big decline in my haelth with the following symptoms.

    mood swings, nervousness, irritability, and severe anxiety
    abnormal sensations,
    muscle twitching,
    muscle atrophy, and
    decreased cognitive functions.
    at one stage i actually thought i was going insane,

    I visited my doctor who prescribed antibiotics as she believed it was sinus related, however no joy. She ordered blood tests and my results came back High Cholesterol and an abnormal liver function test result.
    I then retraced my steps as to when all the symptoms above started, and then it dawned on me that they had started when i had commenced the larger amount of oil supplement as recommended on the packaging. I searched the Internet in relation to fish oil intake and came across this article and others which related to mercury poisoning on anxiety forums( as i thought i was suffering from an anxiety disorder) . I stopped the fish oil immediately and within 2 days my symptoms subsided, A week later they virtually left me. I am awaiting further blood tests as a follow up and have arranged an appointment again with my doctor to discuss this. It goes without saying in my case and as you have explained too much is not better. I would never take these supplements again and i am even apphrehensive about taking fish now.

    • Wow – Reading your story just blew me away.

      I have virtually EXACTLY the same story.

      I’m stopping Fish Oil supps today and see how I go for the next few weeks and if the following goes away:

      mood swings, nervousness, irritability, and severe anxiety
      muscle atrophy
      decreased cognitive functions.
      at one stage i actually thought i was going insane,
      unexplained high cholesterol for somebody who has a brilliant diet otherwise and runs 70 kilometers per week and is extremely healthy and fit otherwise, pretty well a health and fitness junkie………………………..

      except I take a high dose around 4,000-4,500 mg of fish oil daily to try and combat high cholesterol without using statin drugs.

      I will report back in a few weeks.

      Regards James

      • Yes James its true, actually taken me until now to eventually get rid off all symtoms ( I highly recommend renew life heavy metal cleanse you can google it) I really thought i was having some king of break down. But thankfully now im great. Would never touch fish oil/ omega supplement again.

    • My friend, brother and I all suffered from anxiety when taking fish oil supplements. I know that I am particularly sensitive to oxidative damage due to autoimmune and gut issues (I respond very well to vitamin C, a great anti-oxidant). I would suggest that it was not mecury at all but the fish oil processing that was the problem. Since researching about the fish oil process, I’ve learnt that when companies ‘molecularly distil’ the oil, they produce an ‘ethyl ester’ form of omega 3. This is apparently difficult for lipase to clever (breakdown) and requires our body to donate the necessary triglyceride backbone before the omega 3 is accepted by the body. Perhaps this causes oxidative damage? I know there is a link between inflammation and depression/anxiety, so it wouldn’t be surprising. Eat whole fish such as salmon, I get zero issues no matter how much I eat. I don’t think higher doses of the triglyceride form of fish oil would be a problem, this article doesn’t seem to address that complication.

  44. “The only fish oil study lasting more than four years showed an increase in heart disease and sudden death”

    This is NOT true. The mean supplementation and follow-up in JELIS lasted 4.6 years (Lancet 2007; 369:1090-98). The addition of EPA to low-dose statin therapy resulted in a statistically significant 19% reduction in the risk of major coronary events, defined as sudden cardiac death, fatal or nonfatal MI, unstable angina, or the need for revascularization.

    I suggest that everyone interested in the role of fish oil in CVD read the excellent article by prof. Clemens
    von Schacky: Omega-3 Index and Cardiovascular Health. Review. Nutrients 2014, 6(2), 799-814.

  45. Is about 5grams of omega 3 from sardines too much? It is my cheapest protein source. should i limit sardines?

    • Re:


      May 14, 2014 at 11:01 am

      Just eat the whole fish…

      and your

      Dietary supplementation with Lovaza and krill oil shortens the life span of long-lived F1 mice

      (and does “administration of krill oil (1.17 g oil/kg diet)” [ibid.]
      mean g/kg of body weight or
      g/kg of food weight)


      Recommended Daily Omega 6 Intake
      Last Updated: Jan 14, 2014 | By Bridget Coila

      of 17 g/d. for adults


      The paleo <2% of kC

      and the unclearness to me in the n-6 articles as to using the EPA + DHA total gms. vs. the weight of the whole fish oil (or in my case, krill oil) cap to calculate n-6/3 ratios,

      which would require a lot of n-3 regardless, to = the 1:1 a 2000 CE study found best

      ("Keep in mind from the last article that the optimal ratio of omega-6 to omega-3 is estimated to be between 1:1 and 2.3:1" Kresser ibid.)

      [© 2000 American Society for Clinical Nutrition

      Polyunsaturated fatty acids in the food chain in the United States1,2])

      or even the 2.3:1 mentioned:

      thus, elaboration thereon for me, please?

  46. Kevin, being labeled as a quack on a quackwatch.org does not mean you are really quack and your promoted healing/teaching is wrong. Gary Null and many others are on quackwatch.org but does not mean they dont know anything about health.

  47. months ago I had a blood teat and my cholesterol was 240. hdl-56, trigl.-193, ldl-140. My Doctor prescribed fish oil. After 3 months my choleserol was 290. hdl-67, trigl.-127, ldl-198. My doctor then prescribed a stain. I refused to take it and instead took plant sterols daily before meals and 1 teaspoon of fiber. After 3 months, my cholesterol was 289. hdl-59, trigl. 195(back up) and ldl-191. My Doctor insists that I take the statin. Instead, I have opted to run 30 minutes daily, limit my choleserol intake, and cut out all refined sugar. Do you have any other suggestions, should I take low levels of fish oil?? Thank you!

    • I would heavily caution against the statin which you are rightfully questioning since they have severe and sometimes irreversible side effects of muscle atrophy and other things. Your cholesterol levels are not bad, and the high hdl says you are body is working fine with them. The best way to reduce triglycerides imo is to reduce carb / sugar consumption, starting with all refined flour. If you did that for a few months the triglyceride would probably drop considerably.

      Dr. Perlmutter in Grain Brain, which I strongly suggest reading, cites Dutch studies actually showing that cholesterol levels higher than yours are associated with the best overall levels of health and well being; your levels are not detrimental, and a statin would imo not help the triglyceride level but only potentially lower the cholesterol to unhealthy levels; your body needs it for all sorts of reasons. Continue to question the doc and maybe look for another one.

    • Try Niacin, and make sure it’s NIACIN, not niacinamide (flush free niacin). Cut out the fish oil and each whole fish instead. Keep up the plant sterols and exercise, that sounds perfect. Also, as you’re obviously aware, fiber can help lower cholesterol (psyllium husk is good). Fructose seems to be a contributor for higher TG’s, so as well as cutting the sugar, don’t get stuck into fruit juices (e.g. ditch the OJ in the morning). Good luck and good health to you.

  48. I’ve recently started taking fish oil and have been feeling good until last week Friday when I felt my heart rate change. Out of nowhere I felt like it was fluttering or skipping a beat. So last night I looked up what was wrong with me and I was having palpitations. I had a feeling it was the fish oil. So I stopped taking it and can feel my heart rate going back to normal. But I was nervous at first. Then I found this article. And im glad I did. Hopefully i wont feel that flutter again. Not cool. It was like my heart was struggling to pump blood through my vessels.

  49. It’s critical to verify which fish oil brands the studies used. The bulk of fish oil supplements use soy bean oil as the base oil, rendering them almost totally useless. Soy bean oil is toxic in small doses, let alone taken daily in such a large amount as several caps a day. Long term, the inflammatory effects of this toxic oil which, just to add to the inflammatory effects, is also very high in omega 6, would no doubt cause disease.

  50. is this true of krill oil? just curious….
    i bought the FCLO and my kids took it once and i am having a heck of time getting this to be a daily routine. i don’t even want it. made a pot of elderberry syrup…going to try it mixed in that tomorrow. i was actually going to start buying the barleans omega swirl in a fancy flavor and squirt it in that but came on here first to see what you had to say. soooo, that idea is out the door:(

  51. Hi Chris
    When ever I take high strength fish oil or take recommended dosage on bottle, after a few days I have blurred vision,feel depressed and as if almost drugged.
    I am curious if anyone one knows what causes this. I am OK if I just eat fresh salmond or tuna.

  52. Good read. If use of fish oil supplements or high doses are not good for you in the long term, does that apply also to krill oil where a much lower dose is needed?

  53. Chris this article is right on the money. My experience confirmed your conclusions a year or so ago after I upped my intake of fish oil to try and counter night-time arrhythmia and noticed a disturbing affect on my heart rhythm. I consulted my cardiologist who confirmed that fish oil wasn’t necessarily beneficial. Then I read about the study indicating it can cause prostate cancer. Although I still have some reservations about that study, I cut it out supplementing with fish oil entirely at that point. I like your recommendation of the fermented cod liver oil but still think eating salmon and/or sardines a few times a week is best unless you have a particular health issue you are trying to overcome with supplementation.

  54. I just found out that my tryglicerides have gone to about 220. My dr suggested exercise,diet and taking 3 fish oil supplements a day. What do you think?

  55. I’m a 35-year old male and a budding long distance runner.

    I started taking fish oil weeks ago and this is the ingredients list:

    (per 1 soft gel)
    Fish Oil: 995.0 mg
    Providing EPA: 180.0 mg
    Providing DHA: 120.0 mg
    Vitamin E: 0.50 mg

    Other ingredients: Gelatin, Glycerine, Purified water.

    It recommends 2-3 soft gel capsules per day.

    My question is – is it safe? Will it improve my long distance running in any way? – or will I be ill in the long run?


  56. Lydia,

    Your knee pain may have nothing to do with a lack of fish oils. It could be purely due to incorrect running technique, wrong shoes, or overpronation. Perhaps your are running with shoes that have big, thick heal, which puts extra stress on your knees. However, if you move to minimalist shoes do it slowly as it could lead to injuries.
    What this video http://www.theguardian.com/lifeandstyle/the-running-blog/video/2013/apr/17/how-run-barefoot-video

    Also watch some other of Ben Le Vesconte’s videos on YT.

    Knee probs can be due to tight IT band, so do stretches, there are a few good videos on YT how to do IT band stretch.

    If you have money get your running analysed by profesionals and see if there is anything you need to correct.

  57. Chris, I am a vegetarian and I don’t eat meat or fish.

    I’m a 50-year-old female. I lift weights and run and I have recently been having problems with me knees. I take about 1200 mg of Omega 3s a day in 2 capsules. Do you think I should take extra capsules because I’m a vegetarian?

    Please don’t tell me to eat fish 3 x a week because I won’t do it!

  58. The other takeaway from all of this is that real objective for us should be to eliminate nearly all polyunsaturated fats from the diet. What little we do get should be in a better balance of Omega-3 to Omega-6. But I get the feeling reading some of your sources that our actual biological need for Omega-3 and Omega-6 are really very trivial, and we should not try to supplement either source through oils.

  59. The main problem I see here is that we don’t know if the bad long-term results of taking commercial omega-3 fish oil products stems from the fact it is omega-3 or from the fact that the oil was rancid at the time it was ingested. Presumably it is the rancidity of these commercial products that is causing the most harm?

  60. Thanks Chris for the good article.
    If you do not mind my question please..

    You said that Whole fish is a good source of omega-3 instead of taking fish oil capsule because Omega3 is easily to be oxidize so how to cook the Whole-fish to not produce the oxidation in its oil?


  61. Hi,

    I am considering taking FCLO – but I am confused by this statement:

    Some may ask why I continue to recommend fermented cod liver oil (FCLO), in light of everything I’ve shared in this article. There are a few reasons. First, I view FCLO as primarily a source of fat-soluble vitamins (A, D, K2 and E) – not EPA and DHA. Second, in the context of a nutrient-dense diet that excludes industrial seed oils and refined sugar, and is adequate in vitamin B6, biotin, calcium, magnesium and arachidonic acid, the risk of oxidative damage that may occur with 1g/d of cod liver oils is outweighed by the benefits of the fat-soluble vitamins. So I still recommend eating fatty fish a couple times per week, and taking cod liver oil daily, presuming your diet is as I described above.

    My question is this – if my diet isn’t nutrient-dense are you saying taking FCLO is not recommended? I am working on having a nutrient dense diet, but it’s been difficult with work and travel. I was considering taking Green Pastures FCLO. Please advise. Thank you!

  62. I recall coming across a forum months back in which people were discussing how their inflammation and pain increased when they began fish oil. This was about when I started taking it at a high dosage as prescribed by my naturopath. I have chronic fatigue, so I am no stranger to pain and experience it regularly, but particularly in the past few months. My paleo diet has helped me in so many ways, but these aches don’t want to give. Anyways, I noticed this week that my pain was subsiding. I was about to open my new fish oil and paused in thought. Oh my gosh. I have been off of it for a week and I have been feeling stronger and less tender. Could that forum be correct ? I immediately checked your thoughts and well apparently you don’t recommend it. I will stop the supplement. Have any thoughts on this, have you seen this reaction to fish oil or read about it ?

  63. I can report one thing that fish oil definitely does do (at least for me) – improves skin appearance, texture and reduces oiliness, and as a result improves the condition I suffer with – Sebhorreic dermatitis. Interestingly, I have noticed that taking too much (1-2 capsules daily is optimal for me) makes my skin worse and makes me feel fatigued.

  64. What do you feel about krill oil? Dr Mercola advocates it over fish oil because it has antioxidants and its in phospholipid form . . .

    • 1) Mercola is a nut. I’d look to Andrew Weil when it comes to alternative medicaine.
      2) Fish Oil taken with mixed tocopherols is just as good as Krill Oil. The prblem iwth Krill is that it’s just not environmentally sustainable at the moment.

      • Let me add that Weil isn’t right about everything. His outdated view of saturated fat being a killer is a glaring example of him being dead wrong. That said, his writings on vitamins and supplements are spot-on from what I’ve seen.

  65. I’ve been taking 6 grams of fish oil (3,600 mg of Omega 3s) for the past 8 months and now I have high glucose. Could there be a correlation?

      • I find it odd that I’ve suddenly become diabetic. I don’t have the risk factors or the symptoms (weight loss, thirst, frequent urination). I’m physically fit. Just have high glucose over the past few months around the time I started megadosing.

        • You should look into this if you haven’t figured it out already. I recall reading something about this on Chris Masterjohn’s site. You could be on to something. That’s a lot of omega-3.

    • There are studies that correlate insulin intolerance with intakes of saturated fats. I doubt small quantities of fish oil could do it, but I imagine there is biological diversity and some people hyper respond with insulin resistance to particular foods. Have you thought about buying a glucometer and starting to check before-meal and 1 and 2 hours after meals? That lets you start to associate glucose surges with particular foods.

    • hi! I was just reading thru some very interesting articles by Prof. Brian peskin, stating that fish oils actually worsens diabetes; and again, that diabetes is caused by the lack of parent essential oils, which make all the necessary PG1, PG11, EPA’s,-3,6,9.; DHA; AA etc. without supplementing on adulterated, highly oxidizing ‘derivatives’, no matter their processing…! I’ve been scouring thru his findings, and feel fairly secure he could be onto something!-so I’ve just gone out and bought organic flax, black-seed [nigella sativa], sunflower, walnuts, sunflower- seeds [pepitas]; raw almonds, organic, cold-pressed coconut oil.[just by squeezing a capsule of astaxanthin into Extra virgin olive oil, will keep it from oxidizing]-heating oils, cause the loss of oxygen transference capacity, which again, is another reason why fish-oil supplements are unrecommended. There is much more to his research findings, and since being on a high dosage of fish oils from a ‘trusted’ brand that has a higher % of DHA to EPA, it appears my health has declined, and my arteries are clogging up, i’ve gained weight, despite care- so I also bought Nattokinase and Serrapeptase, to clean my arteries, and re started a regime for this ailment- I wish you every success- may I also recommend Clayton nolte’s Water re-structurer- i’m about to purchase the portable and home units ! I was speaking with some naturopaths today, who all recommend eating grass-fed meats, and organic chicken, with their respective fats, to cook with Ghee and coconut-oil but to really cut down on carbs and sugars, and hype up the veges, esp. leafy greens[collards, kale, swiss chards, gotu kola, spinaches-such a variety.. brassicas[broccoli, brussels, cauliflower, cabbage..] and do look into trying a standardized Curcumin[turmeric] supplement biocurcumin has 4, 300 or so mg. of curcumin, which is potently good for so many things..i could go on…x

    • How can we possibly know if the oil is high quality, when:

      1) Manufacturers are often bleaching and deodorizing rancid oils

      2) A given manufacturer can source oil from different places, thus changing key parameters

      3) There is no published guideline for determining rancidity, and metrics around this concept are not required to be on the label.


  66. I am still trying to decide whether or not to continue with my liquid fish oil supplement after reading all the pro’s and con’s. I have a hard time putting anything into my body that may have poisons in it ie, pcb’s, mercury, etc, however I have been taking one particular fish oil for 2 years daily now at 1205mg per day with a meal and notice that my arthritis pain is reduced dramatically, but only with this one particular brand. Other brands claim to have a bit more mg but do not work for me. I had been on NSAIDS for years and have been off of them since taking this fish oil. I have tried to go off of the fish oil only to have my symptoms return within 2 days. Do not think I could possibly eat the amount of fish to get the same effect! Hmmmmmm.

  67. Hi Chris,
    I’ve recently being doing some research on Omega-3’s and fish oil supplementing for speech delay in toddlers as well as benefits for children with autism. Some studies and many parents claim to see a dramatic improvement in their children when supplementing with fish oils or Omega-3’s. Any thoughts?

  68. Hi Chris,

    I believe I have EFA deficiency. I won’t go into full details but the main reason is because I get really bad dry eyes on a daily basis. Now I noticed this completely gone when I started eating 2 tins (90 grams) of tuna in olive oil each day.

    So I was wanting to see what your thoughts are on:

    – EFA deficiency and best way to beat this
    – eating too much tuna or particularly tuna in olive oil
    – hempseed oil

    Much appreciated.

    p.s. love you articles and site!

  69. “The risk of heart attacks is more dependent on the number of LDL particles than on the amount of cholesterol they contain. Fish oil can slightly increase the amount of cholesterol in LDL, but it also significantly lowers the number of LDL particles. The end result is beneficial. There’s no reason to worry that taking fish oil will sabotage your cholesterol control and every reason to believe that it will benefit your heart and general health.” – Integrative cardiologist Stephen DeVries, M.D. of Northwestern University’s Center for Integrative Medicine and Division of Cardiology in Chicago

  70. Hi Chris and viewers,

    I was taking A Lot of fish oil caps & liquid, nordic naturals brand to combat a certain neuralgia, after the neuralgia was subsiding, i notice the joints around my knees started to feel weak. After quitting fish oil for a few days, 4 days at least, i’ve been having difficulty in waking, while the knees start to have some burning pain. Was wondering if you can recommend foods or supplements, kale spinach, broccoli carrots cucumber i know of…I Just dont need sugar and anything omega-related like fish…I have slight burning pain when sitting as well…Everything else in my body is fine, im a young adult.

    I dont expect an answer quickly, but i constantly check my email & will view the site. Thanks for reading….

    • hello 🙂 there is a unlimited range of possibilities to what you are describing. it sounds a bit auto immune related (autoimmune complexes lodge all over the body a trigger localised inflammation) go back to basics with diet , not too much intervention with supplements and allow the body to communicate. The body often goes back in time when healing so it might be an old injury coming good

  71. long term 15 year study correlates n3 acid intake with lower body fat http://www.ncbi.nlm.nih.gov/m/pubmed/23887855/?i=1&from=fish%20oil%20long%20term. Good info fyi. As always, without excersize you are done. Eat green vegetables too. Drink water. I take 4 G of EPA/DHA a day and as a physically fit 24 year old, I feel it helps with my recovery time, and my memory and my stress level. I also take it with other oils to help absorb (usually olive) and dark leafy greens, so they can use the oils to help vitamin absorbtion.

  72. Hi Chris, I really appreciate your work. I have a question that so far nobody in the nutrition world has been able to answer for me. I agree with you that omega-3 oils are highly unstable and eating oily fish is a much better idea. But what happens when we cook fish? Aren’t the polyunsaturated fatty acids also being damaged and creating free radicals? It would seem that only raw preparations such as sashimi or ceviche are beneficial. Am I missing something? Thanks!

  73. Hello – i would like you to answer what you think – and if anyone else wants to answer it can be nice

    i started giving my dog oil fish reading about it in this link :


    they say my dog needs 1000 epa a day and that epa is better – so i looked and found an expensive fish oil that say he has this ratio – 400epa : 200dha and i thought this was good do you think its actually bad that it has this amount of epa ? the company making it says its better the more epa there is i have a cheaper fish oil and it has 200:200 ratio should i switch to it ? is 1000 epa to much maybe i should just give 1 pill a day of 400 ?

    would be intersted to hear what you think

  74. Just wanted to say I have primary sjogren’s syndrome (autoimmune disease) and when I take fish oil I get exponentially worse…all my symptoms skyrocket. Then I stop and it gets BETTER. I have read over and over how fish oil is supposed to help with autoimmunity but it makes me worse. I thought I was a freak of nature….not I am not so sure. Taking curcumin…another natural anti-inflammatory…makes the symptoms of my autoimmune disease way, way worse as well. I want to try sea buckthorn oil…supposed to be great for sjogren’s….but I am too scared at this point. Have you ever heard of these things making autoimmune disease worse? Thanks for this info you posted. I think there is definitely something to this.

    • not surprised that fish oil would worsen auto immune conditions , the right oils improve the integrity of all cells including the ones that attack organs in auto immune conditions.

  75. Thank for the info Chris. I love that you are open enough to question what “everybody” else is doing. I have wondered about fish oil for some time. I am curious if you have any thoughts per Michael’s July 25, 2012 post about oxidation of FCLO. I know fermentation is an ancient practice, but it seems that the long process would create more oxidation.

  76. I wonder what Dr Barry Sears would have to say about this? I know he has recommended 3-4g a day of Omega 3’s for my RA accompanied with his anti-oxidant formula (capsules) which he believes helps reduce that oxidative stress. He recommended I take 2 per day.

  77. I’ve been taking fish oil — Nordic Naturals actual oil, not the supplements, in order to avoid a daily aspirin because the aspirin was killing my stomach. I know fish oil has a blood thinning effect, so I was thinking I was doing a good thing by switching. I take a daily aspirin as a preventative measure because I had a DVT while pregnant. I also have a family history of blood clots, so it’s imperative that I find natural ways to keep my blood thin. Fish oil is the most tested natural product for this purpose. I know other herbs and things thin the blood, but I wouldn’t know how much to take or when I’ve gone too far. Any advice on what kind of doctor I can talk to about this or where to find information that will help?

    • Best bet is to clean up your diet/lifestyle an for added assurance you cau use Nattokinase to “thin” your blood and ward of blood clots..Cayenne pepper , Serrapepase also do the same but Natto is likely your best choice..

  78. Article summary–My comments to the right.
    The benefits of fish oil supplementation have been grossly overstated–Yes, especially at low doses.

    Most of the studies showing fish oil benefits are short-term, lasting less than one year–except for Aleutian natives and South Pacific Islanders who eat a lot of raw fish.

    The only fish oil study lasting more than four years showed an increase in heart disease and sudden death–except for the epidemiological studies on South Pacific Islanders and Aleutian natives who eat a predominantly fish diet most of their lives.

    Fish oil is highly unstable and vulnerable to oxidative damage–until it it eaten. At which time peroxides and hydroperoxides a a normal part of essential fatty acid and prostaglandin metabolism which includes immune system function and just about every process in the body.

    There’s no evidence that healthy people benefit from fish oil supplementation–See above.

    Taking several grams of fish oil per day may be hazardous to your health–Yes, but because of increased risk of strokes and colon cancer, not heart attacks.

  79. And the fish oil industry is responsible, it is now becoming apparent, for the increasing numbers of deaths of seabirds from starvation, and failing to raise any young, again from lack of food. As we vacuum up the contents of the oceans for our own precious diets, we might spare a thought for the other species condemned to live on the same planet as the greedy hominid.

    • Fish oil increases intestinal permeability, what is also does is increase CELLULAR permeability , which is a GREAT thing..All in all getting your nourishment from whole clean food sources is what we should strive for and supplementing temporarily when one’s diet is less than optimal or when fighting dise eases..The other thing to note and this has baffled many health professionals, is how one metabolises their sustenence..Hippocrates said it over 2500 years ago “one man’s food is another poison.” This held true back then and it STILL does TODAY…Just look at all the conficting data you see on many of the studies done, even the gold standard,double blind placebo studies.Then look at ALL of the diets out there see how many people fare well and how many do very poorly..We all need to find out what is best for US … Not because something works well for some means it wold work well for EVERYONE..This is a giant mistake…

  80. Valid information, Chris. When I read the title of the article, I immediately thought “ I think I know where he is going with this.” The intake of EPA/DHA can decrease amounts of other beneficial fatty acids, as well as have some deleterious effects if other nutrients are not used in concert.
    For example, an increase in consumption of EPA will decrease GLA which has anti-inflammatory and anti-cancer benefits, as well as decreasing oleic acid which is a known cardioprotectant.
    An increase in DHA will have the same effect on GLA and oleic acid that EPA does.
    As well, an increase in GLA will decrease EPA, and an increase in ALA and EPA will decrease oleic acid.
    To optimize clinical benefits, fatty acids must be administered in combination. Doctors NEED to stop thinking in terms of “either…..or”. They need to use health promoting fatty acids IN COMBINATION to optimize biochemical status and thereby maximize clinical effectiveness.
    Lastly, Chris, I recently came across a paper by Ottestad and Vogt, et.al. in the British Journal of Nutrition, 2012, 108, 315-326, in which it states that oxidized fish oil DOES NOT influence markers of oxidative stress in healthy subjects.”
    However, this was a very short term study in already healthy individuals. This paper concluded that a daily intake of 8 grams of oxidized fish oil did not influence a variety “in vivo” markers of oxidative stress, lipid peroxidation and inflammation in healthy subject after 3 or 7 weeks of intervention.
    Have you seen any studies similar to this?
    I am on the look for long-term studies since, as you pointed out, almost all fish oil studies are done on the short term.
    Thanks again for everything you do.

  81. Dear Chris

    I stumbled upon your podcast a few weeks back because of the word “skeptic”. Subsequently, I have listened to a number of your podcasts and read a number of articles. I had never heard of the Paleo Diet before, but your version makes a lot of sense.

    I have just read the above article on fish oil supplementing and I am sad about this although it makes sense. The reason I am sad is that I have a serious problem with lack of focus, boredom and procrastination. I previously used to eat a “healthy diet” of lots of fruits and veg, some meat, wholewheat bread and virtually no fat – you know, the previously healthy diet.

    I also used to use coffee to get me through the day, but after months of two to three cups a day I would get exhausted so would give it up for a few weeks. The symptoms appeared to be adrenal fatigue. The problem is that I would eventually get back onto coffee again and repeat, repeat, repeat for twenty years. Last year I was really desperate and discovered Ritalin.

    Initially I thought I had found the Wonder Drug. I could focus, I had enthusiasm for the most mundane chores, I plowed through task lists in days that normally took months or years because of my procrastination issues. But everything that seems too good to be true always comes to an end. After about six months I got nasal cold symptons that just would not clear up, I needed sleeping tablets to fall asleep at night and the dose of Ritalin was not helping so I had to increase it. Round about then I found your website and decided to quit Ritalin and try your theories.

    I cut all grain products except soaked rolled oats for breakfast, cut all industrial seed oils, started eating much more fat/oils with every meal and feel much better. I find that if I eat only fats, protein and veggies for breakfast I struggle big time with exhaustion during the morning hence the oats. I guess my body is still carb dependant and not used to getting energy from fats yet.

    My questions are thus:
    1. Can I eat my way out of procrastination and will I ever get the “Ritalin Enthusiasm” by eating? I assume it has something to do with not having enough of the right fats in my brain?
    2. What can I eat, how much and how often to get my life back?

    Thank you for your research. You have already made a difference in my life

    Kind regards
    Murray (South Africa)

  82. Thanks for the article; very informative. One thing I don’t understand about achieving a healthy omega 6/3 ratio: Omega 6 is essential to health. Apparently the RDA is about 10 or 11 grams per day. Granted, most Americans consume more. I use no cooking oils, or any other pure oil, for that matter, consume no processed food, and consume nuts or seeds infrequently and only in very small quantities (e.g., less than 1/4 oz serving). My daily intake of omega 6 is probably about 5-8 grams/day, which means, if the RDA is accurate, I’m deficient in omega 6’s. However, even with this low consumption of omega 6, to achieve the desired ration of 3/1 or less, I would still need to take 2 or more grams of fish oil a day, which you point out, might be unhealthy. I would never be able to get enough omega 3’s from natural foods, as I’ve heard that conversion from flax or chia is only about 5%, and, I can eat only so much fish (maybe about 6 oz/week, max). And especially for someone consuming the RDA of omega 6 (actually 13 g/day for men), how could they ever achieve the desired ratio of 6/3 without taking quite a lot of fish oil supplements? Thanks for any light you can shed on this!

  83. Chris – I have taken FCLO for many years and did not get the amazing inflammatory affects I would have liked to have seen until I started eating a high quality blend of chia. I am hoping some fresh studies arise soon showing that ALA does convert to EPA and DHA because in many anecdotal stories, people are having great results from this chia blend. I do believe that FCLO is important as you mentioned to attain vitamins A, D, K2, E. My actual question is about Krill oil. As I understand it, Krill oil does not go rancid like fish oil but you state above that your thoughts on Krill oil are the same as fish oil. What do you know about the rancidity of Krill oil?


  84. Chris:

    Thank you for the article regarding the negative health consequences of fish oil. There is a lot of information in your fish oil articles. I would like to take the oils; however, I don’t want to have negative health consequences. Would you mind simplifying some things for me? Thank you!

    1. How much FISH OIL would you recommend as the safest upper limit for someone eating the average American diet (please specify is that measuring the total oil, or the EPA and DHA, and what type, such as ethyl ester or what?)?

    2. How much KRILL OIL would you recommend as the safest upper limit for someone eating the average American diet (please specify is that measuring the total oil, or the EPA and DHA, and what type, such as ethyl ester or what?)?

    3. I have heard that ALA promotes good prostaglandins. Is it okay to take ALA such as PRIMROSE OIL? If it is, should I cut back on the amount of FISH OIL or KRILL OIL (whichever I am taking), while I am taking ALA , since some ALA is converted?

  85. Great article doctor. I am wondering, though, if there has been any testing of the oxidation level in the fermented CLO you recommend (if this test is actually possible). I have actually been taking green pastures for some time but literally a week before stumbling onto your article I switched back to regular CLO as I could not reconcile how a delicate oil left in a vat to ferment wouldn’t get super oxidized. You said in this and a previous post that green pastures is “cold processed” so it’s not subject to high levels of oxidation. However, from what I understand, ‘cold’ in this context really means ‘not heated to pasturization levels (like ~160+)’, not actually cold as in ‘refrigerated cold’ (or else fermentation wouldn’t happen). Plus, from what I know about fermentation is it requires access to oxygen and room temperature for many days, ideal conditions to oxidize any oil, whereas the ‘regular’ clo’s are only heated for seconds and presumably under oxygen free conditions. In fact, Green Pastures says you don’t even need to refrigerate their product, and this jumps out at me because it sounds like the oil must be completely oxidized on delivery if further refrigeration isn’t even a concern of theirs anymore.

    It seems to me that your biggest concern with fish oil is oxidation and you did really in depth research on it for regular fish oils. But I feel like the ‘cold fermented’ process that blue pastures needs more analysis since you ultimately recommend it so highly, especially in comparison to regular CLO. I have not seen anyone question their oxidation levels with their process and that makes me concerned. It seems like everyone is taking it for granted that with the word ‘cold’ before processed that oxidation is not a concern, but it seems to me that it’s a huge concern if it is left out to ferment for days. I understand it has more vitamins, but does that really offset the possibly rancid oil left exposed to oxygen for days? ie Would you take a spoonful of almond oil (or other polyunsaturated fat) that was left out for a week to oxidize at room temp (defined as cold processing) if it had those vitamins at the end of the process? Additionally, if k2 is the only extra vitamin you could get that from butter. I’m genuinely curious and would like to hear your thoughts before deciding which way to go with my CLO/FCLO. Thanks!

  86. I wonder how helpful or potentially dangerous are no-fish sources of Omega 3, like Flaxseed Oil, etc.
    Also, I second that question by Jeremy above about “fish oil supplementation for athletes who frequently train at high intensity?”

  87. Hi

    I’ve been taking fish oil for a very long time at quite a high dose (7.5g a day of EPA/DHA). Obviously your article has me concerned.

    However, I’m not completely convinced that its the fish oil itself that’s causing the increases in oxidative stress. Nowadays fish are horribly contaminated with the myriad of pollutants we’ve dumped into the ocean. Particularly concerning are the mercury, pcb, and dioxin levels in large top-of-the-food chain fish like tuna and halibut. These pollutants become highly concentrated in “crude” fish oils. Cod liver oil is especially contaminated because of the fact that toxins are stored in large part in the liver of the fish.

    As far as I can tell, none of the studies demonstrating the oxidative risk of fish oil control for toxins which may be present.

    Also, assuming you’re right that high levels of fish oil supplementation increase oxidative stress, it makes sense to adjust the omega 3/omega 6 ratio primarily by reducing omega 6 consumption, but in this context your recommendation to eat fish instead of taking fish oil supplements has the problem of increasing dietary intake pcbs, mercury, and dioxins. The correct move would be to supplement with a highly purified fish oil at the minimum dose necessary to achieve the ideal omega 3/omega 6 ratio, and then to avoid fish entirely.

    • ALL fish oil must achieve FDA mandated safety standards.

      So called ‘highly purified’ fish oils are nothing more than an expensive marketing scam that relies on fear not facts.

      Fish oils contain negligible heavy metals because these metal are not oil soluble.

      Humans (unlike rodents) are not significantly affected by dioxins.except in extremely high dosages.

      PCBs are not highly toxic. http://blogs.mcgill.ca/oss/2013/08/30/pcbs-are-not-toxic-time-bombs/

  88. I’ve been taking fish oil for the last few years, and all the sudden I can’t tallorate proteins either meat or milk products,, I’ve seen all doctors and there’s nothing wrong with me according to the doctors, it is possible for this to be related with the intake of fish oil?

    • As Mat LaLonde has discussed, lipid peroxides break down into alcohol functional groups during digestion. While consuming oxidized lipids may not increase cellular oxidative damage, the by-product of their conversion into alcohol functional groups is aldehyde – which is very toxic to the liver. Consuming fresh (unoxidized) PUFA, however, does increase the risk of oxidative damage because those PUFA are incorporated into cell membranes and phospholipids, which makes those cells more vulnerabile to oxidation.

      It’s very complex, but this explains why studies of people consuming oxidized lipids don’t show an increase in markers for oxidative stress.

  89. Thanks for all your work Dr. Kresser.

    I have two questions, however:

    Would increasing your antioxidants from sources such as fruits (oranges, berries) and vegetables (kale, broccoli, etc.) reduce or even eliminate all potential damage from fish oil?

    Also, how does krill oil compare to fish oil?

  90. What are your thoughts about fish oil supplementation for athletes who frequently train at high intensity? This type of training usually causes an increase in inflammation and it has been said high-quality fish oils are potent antiinflammatories that can assist in recovery and maximize training efficacy. Are there any studies out there that shed light on whether athletes should be supplementing with fish oil?

  91. Hi Chris,

    Really curious about taking fish oil (vital choice wild alaskan) during pregnancy and especially while nursing. I’ve been following Nina Planck’s recommendations of 3,000mg. In your opinion, does this fall into the beneficial short term use category? I have been supplementing and planned to until my daughters could consume fish on their own. They do take CLO. Thanks very much!

    • If you eat 1 lb. of fatty fish (salmon, mackerel, herring) in addition to both you and they taking FCLO, that should be enough. No need to take additional fish oil above and beyond that.

  92. It has been common knowledge that the actor, Cary Grant, died from an unusual addiction to fish oil capsules. The coroner indicated it was due to cardiac problems; however, these problems was caused by an overconsumption of fish oil capsules.

    • He died at age 86, at which point he had most likely been taking the capsules for about 40 years, and that is well beyond current life expectancy.

  93. If Cod Liver Oil is good (at least fermented CLO), then one would think that eating fresh whole cod, including its liver (and maybe other organs) would be even better, assuming one can get hold of a good quality fresh cod.

    I assume this is what traditional Inuit actually did, anyway (cod, or whatever fish they caught).

    Is there anything inside a fresh cod that we shouldn’t be eating?
    I guess people might find eating the guts distasteful, but would it actually do us any harm?

    If so, then presumably, if one was skilled with a knife and knew what to leave in and cut out, should do the trick. Then cook at eat whole. Does this sound plausible?

    After all, some of us eat mammal organs with equanimity, so why not fish organs?

  94. Chris I wonder if I am missing something obvious as I read all the comments (plus googled) and will be the first one to ask this: Where do I gather the info off of the Green Pasture FCLO to fulfill your daily recommendations of 10,000- 15,000iu? Thanks

  95. Chris,

    I don’t know if this is the best place to post this. Thank you so so much for everything you’ve done to help us reach optimal health. I just purchased Healthy Baby Code, and I’m very impressed by how well you’ve distilled a ton of information. It was worth every penny.

  96. I agree largely about the reduction of Omega6 being more important.

    You said in a previous comment “We know less than we think about how all of the various constituents of vitamin and mineral complexes behave.”

    I couldn’t agree more. Why is an apple healthier for you than if we took water, sugar, fiber, and a vitamin complex and took those instead? There are probably many more types of the vitamins we know of that we are generalizing too much. There’s most likely small amounts of nutrients in whole foods that effect our bodies, that we don’t even know about.

  97. Here is an idea for salad dressing: sour cream. I grew up in former Soviet Union, and the only choices I had for salad dressing were sunflower oil, vinegar and sour cream. I always went with the latter. It tastes better in a salad with lots of tomato. When salted, tomatoes release juice that thins sour cream. Uh, taste of childhood.
    Sour cream is very low in PUFA and tastes great. I am surprised it not widely eaten in America. Fear of saturated fat, I guess?

  98. Thanks for your work Chris.
    As you mention, fish oils are notoriously unstable. It’s widely recognized that fish oil supplementation lowers blood concentrations of vitamin E. One reason may be that the Vitamin E is being used up to combat its immediate oxidation in our system. Krill oil will follow the same pattern – though my experience is that it is slightly more stable – so has to be “fresh”.

    My question follows: A damaged oil or fat will often have the opposite effects in the system of its fresh counterpart?

    The quality average omega 6 in the diet is low, low, low. So lumping all O-6 together may be misleading.

    Take beef as an example… you’ve referenced studies that show that the O-6/O-3 ratio in grain beef is 10 times that of grass fed beef. I think most readers can agree that this is imbalanced/unhealthy – for the steer and the steer eater. But if we dig down one notch, how does the grain fed steer reach these inflamed heights? Well it’s dollars we know – and we know naturally grazing animals won’t thrive on grain long-term (or even short-term) but to compound the problem the grain they get is the worst possible omega 6 source – cheap, GMO, round-up laced, rancid grain… not a recipe for healthy tissues. So the beef most of us eat is (of course) way high on Omega-6 – but is this fair to call this “real omega 6”. Similarly is the Omega 6 in eggs, processed food, etc – really omega 6? or some stale and toxic oil-like residue – that just gives omega 6 a bad name?

  99. Hi Chris,

    3 months ago when I started taking Spironolactone/Aldactone for my PCOS to lower my androgen levels. I started to see the lbs start to come off almost immediately and my energy levels return. Hence my exercise levels have increased because of my over all sense of well being. In the past three months I have gone down 30 lbs and my doctor is still concerned about my cholesterol. Mainly the triglyceride levels. Which comes as no surprise to me because the high triglycerides runs in my family. I told my doctor I do not want to take statins. He recommended 4000mg of fish oil per day. He also recommended freezing them so it won’t dissolve until it has gotten into my stomach. I bought some capsules and have been taking them for about a week and I noticed that my weight loss has slowed down. You said fish oil doesn’t help healthy people, but what about obese people with PCOS trying to lower triglycerides?

  100. Would be interesting to see what these peoples other nutrient intake was like…

    We know fats with double bonds are easily oxidized. Did these people have adequate fat soluble vitmains and antioxidants to avoid oxidaiton?

    Like anything we cant draw too many conclusions from such little infomation and such a little picture. Health isnt 1 nutrient or pill. Its a lifestyle, and when that lifestyle can be studied would be interesting to see the results.

  101. Would be interesting to see what these peoples other nutrient intake was like…

    We know fats with double bonds are easily oxidized. Did these people have adequate fat soluble vitmains and antioxidants to avoid oxidaiton?

    Like anything we cant draw too many conclusions from such little infomation and such a little picture. Health isnt 1 nutrient or pill. Its a lifestyle, and when that lifestyle can be studied would be interesting to see the results.

  102. Would be interesting to see what these peoples other nutrient intake was like…

    We know fats with double bonds are easily oxidized. Did these people have adequate fat soluble vitmains and antioxidants to avoid oxidaiton?

    Like anything we cant draw too many conclusions from such little infomation and such a little picture. Health isnt 1 nutrient or pill. Its a lifestyle, and when that lifestyle can be studied would be interesting to see the results.

  103. Hi,

    I had a heart attack 5 years ago and have taken Omacor (1 * 1000mg per day) since. I’m not sure if this is a good or bad thing now. Could you tell me?



  104. MFA are perfectly safe. However, both almonds and avocados contain a fair amount of omega-6 so consumption of these should be moderated.

    • Hi,

      I had a heart attack 5 years ago and have taken Omacor (1 * 1000mg per day) since. I’m not sure if this is a good or bad thing now. Could you tell me?



  105. Chris: Excellent discussion! Where do monounsaturated fats fit into the picture? Myself and many of my Paleo friends have been consuming quite a bit of almond butter and avocados. Do you see any problems arising from this. To my knowledge almonds are much higher in mono than poly unsaturated fats and assuming that we are not eating processed foods and the dangerous seed oils would this be OK provided we are balancing with FCLO and fatty fish a couple x a week?

  106. Hi Chris, this article is interesting, but worrying! I have hashimotos thyroiditis and am avoiding iodine containing food as it definitely worsens the auto-immune attacks – they rocketed after I went on Summer holidays and overdosed on fresh fish and shellfish. I have been taking krill oil tablets on the basis that they don’t contain iodine? Does FCLO contain Iodine? would this be a safe option for hashimoto’s?
    Would appreciate your thoughts!

    • Lex: I don’t think food goitrogens play a significant role in suppressing thyroid function. I prefer FCLO to krill oil because it also has fat-soluble vitamins A & D.

  107. Hi Chris,

    1 small can (213g) of Alaskan Wild Red Salmon contains ~20g of oil, of which ~6g is EPA & DHA. I can easily eat that in one meal!

    Eskimos eat both oily fish and marine mammals. Marine mammals run at a higher temperature than oily fish, so they have a lower percentage of pufas in their fat. Even so, Eskimos are eating a diet high in long-chain omega-3 pufas but they aren’t dropping like flies from CHD & cancer (although they may age prematurely).

    Therefore, is it reasonable to conclude that the omega-3 pufas naturally present in foods = O.K. so don’t worry about them?

    Cheers, Nige.

  108. This is interesting stuff. I have a peculiar condition of longitudinal grooves in each thumb nail. Various MDs have suggested there is an infection or damage to my nails, But I don’t agree as there are no other signs. but when nails are placed end to end, the groove is in precisely the same position on both nails and they are quite deep. This has been developing over the last 20 years.

    I have been using fish oils for several years together with other supplements. Three months ago I started taking 4000mcg of fish oil daily and now it is obvious that my new nail growth is almost smooth and normal. This indicates that the fish oil is promoting good nail growth. I don’t know what it is doing to other aspects of my health.

    I will have a full blood analysis soon, so it will be interesting to see if my usually high LDL is reduced. I eat fish twice a week and otherwise a nutritious omniverous diet. I am 69 and maintain an excellent BMI.

  109. I have been taking roughly 4400 mg. of high quality fish oil plus 2000mg. of niacin-(not the no flush) for a year and recently had labs done. My HDL increased to 105, my LDL decreased to 105 and my triglycerides decreased to 52. In addition, my last carotid artery scan showed a reduction in velocities (which means less plaque). I attribute this to the combo of fish oil and niacin. I eat a very low carb diet and am type 2 diabetic with an a1c of 5.6. After reading this very thought provoking article, I am thoroughly confused.

    I definitely need to educate myself on this issue.

    Thank you for your astute article.

  110. Yes, it’s possible. And you’re the 2nd person in a week to mention a connection between gluten and tinnitus. That’s something I wasn’t aware of – although frankly, it doesn’t surprise me.

    • Ok, here is something I have to share. I used to have auditory hallucinations before which I used to sometimes hear a sound like a higher pitched version of whining. I read about A1 dairy and schizophrenia some day, removed it from my diet and my auditory hallucinations vanished.

      I think if I had removed gluten from my diet it might be helpful also, since I suppose gluten greatly increases the intestinal permeability and allows passage of much more A1 dairy peptides such as BCM-7.

  111. Thanks. Your post will serve as a reminder for me to get vinegar and oil on the side when I order salads. I sometimes forget to do that. That’s probably the one area where I get too much omega-6’s.

    On a possibly related note, I’ve had tinnitus for two years now, and I’ve taken high doses of high-quality fish oil for 15 years. It might be a coincidence, but after going on a strict gluten-free diet about a month ago, and recently cutting out fish oil (6 days ago), my tinnitus is only about 1/5th the level it used to be, and has been at that lower level for five days now. I’ve experienced this low level before, but never for more than 2 1/2 days in a row.

    I took the fish oil to reduce inflammation, but maybe it backfired on me!

  112. Tedd: bread isn’t high in omega-6 (but it does have other problems, such as gluten and the impact of refined flour on blood sugar), so it’s not the issue in this case. Foods high in omega-6 are packaged, processed and refined foods containing industrial seed oils like corn, soy, cottonseed, sunflower, safflower & canola. Chips, crackers, cookies, fried foods, etc. Also restaurants use these oils almost exclusively.

    If someone continues to eat those foods, it’s difficult to say what the lesser of evils would be. The best of the worst choices would be to get them to eat fatty fish 3-4x/week. If not that, then in the short term 3-4g/d of fish oil would probably be beneficial… but as the studies I mentioned in this article suggest, that effect would diminish over time and even reverse.

  113. Chris,

    I agree with your article; it just makes sense. My problem is the rest of my family, who continue to eat bread, and sometimes pasta. Is the lesser of the evils to supplement with 3-4g high-quality fish oil to counteract the too-high intake of omega-6’s? Or would it be better to live with the higher omega-6 intake and limit the fish oil to 1g?

  114. Those are all excellent food-based sources, and provided your intake of omega-6 is low and you’re eating a whole-foods, nutrient-dense diet (which it sounds like you are), I think you’re right where you need to be.

  115. Hi Chris,

    Love your site. I frequent regularly.

    I was just thinking about all the sources I get omega-3 from, and started wondering if I am maybe getting too much.

    I eat salmon about once a week and I have canned tuna once a week (the only brand I buy is Wild Planet. they do it very differently with very high omega-3 and low mercury and no oils and no water added)

    I eat a significant amount of Organic Valley’s pasture butter, probably about 4 tablspoons per day, which claims naturally occuring omega-3.

    I take Green Pastures Fermented Cod Liver Oil / Butter Oil blend daily.

    I also eat at least 2-4 organic eggs from free roaming chickens and sometimes they claim omega-3 on the package depending on where I buy them from (not always though).

    So that’s 3-4 significant sources of omega-3. Is that too much?

  116. Marion: my recommendation is to dramatically reduce omega-6 intake, eat fatty fish 2-3 times a week and take 1/2 to 1 tsp. of fermented cod liver oil per day for all of the reasons I described in this article.

    • – You really didn’t clearly answer this person’s question. Kind of like how you’ve been mildly evading being straight on some of your other responses here, particularly the ones that question your position on this.

      It’s also pretty interesting to me, Chris, that the correlation outcomes you’re presenting here are similar to the correlation presented in the meat causes cancer studies; the ones you spent an hour on a podcast picking apart and criticizing. I agree with you there, and eat red meat everyday. But I can’t agree with you on fish oil.

  117. I have been taking fish oil for my arthritis — 3600 mg daily. I am 61 and was an avid distance runner until felled by hip arthritis (now both sides). I had stopped running entirely and was in such pain that I had scheduled hip replacement surgery for last August. I read an article about 5 months ago, however, that said that most people fail to benefit from fish oil because they do not take enough. By the time I had my pre-op visit with my surgeon, my arthritis have improved markedly — so much so that my surgeon was no longer willing to do the surgery. I was able to begin running again with my running group (3 miles on trails) and had significantly less pain. From my reading of the scientific literature, fish oil has been associated with relief from joint pain (due to its anti-inflammatory properties and other unknown effects). Would you recommend from your assessment of these new findings that I stop or reduce my intake?

  118. Chris,
    thx for another great article.
    Prof. Brian Peskin has been advocating agains fish oils for a long time, more info
    Also google ‘IOWA study on fish oils’, and you also see that fish oils makes worse

    B.Peskin has been advoacing for consuming good ratio of omega 3:6, and then body would be able to produce enough DHA and EPA. Whilst consuming fish oils we get pharmacological doses of DHA and EPA, which is harmful, could even lead to diabetes, CVD, cancer.
    He got a term parent essetial oil (PEO), – which basicly means high quality omega 3 and 6 (alfa linolenic and linoleic fatty acids)

    • Unlikely it would lead to cancer, since it suppresses inflammation and cancers use inflammation to invade healthy tissue and hide from the immune system; omega 6 prostaglandins promote inflammation and also suppress production / activity of natural killer white blood cells which are the first line of defense against cancer cells. Since oils compete with each other absorption of more omega 3 would mean less omega 6 and its inflammatory effects, etc. (John Boik, Cancer and Natural Medicine for all of the above). Please elaborate on what the theory might be for how omega 3 would do this.

  119. Chris, yes of course. I was so focused on toxins exceeding safe levels or allowable limits, that I completely misread the “standards” part. Thanks for your insight re: FCLO.

  120. Suzy: exceeds the standards means “is better than”.

    Eating vitamins in their natural whole food form is always the best choice. When supplementing, D3 is more desirable than D2, but that doesn’t mean we would avoid cod liver oil because it has more D2 than D3. As I said in my previous reply, there’s still a lot we don’t understand about the various constituents and how they work together.

  121. Chris, thanks for your reply. So now I’m confused because from my understanding it’s the D3 we’re after. I was hoping to use FCLO as a somewhat whole food source of vitamin D (more for maintenance than boosting my levels). But now it looks like it’s actually the wrong kind of vitamin D? Could you please shed some light on this for me?

    As for the second part about Prop 65, that’s what I was worried it meant, but was hoping that I had misunderstood it. I’m surprised to hear that their FCLO exceeded the standards. I always thought that FCLO was one of the “safer” alternatives. Could you please share your thoughts on this?

    Thank you.

  122. Suzy: it has D2 because that’s what naturally occurs in the cod livers, apparently. We know less than we think about how all of the various constituents of vitamin and mineral complexes behave.

    The second part means that the detectable levels of PCBs exceed the WHO and California Prop 65 standards.

  123. From the Green Pastures link you posted for their “Product Test Data” – under additional comments it says “Majority of D is D2”. I’m concerned – I thought it would’ve been D3 – do you know why that is?

    Also, do you know what this means: “below .090 PPM PCB WHO/exceeds Prop 65” ?

    Thanks for the very informative post.

  124. Hi Chris, an interesting counter-point here…but I have not read the full study, just the abstract. Frankly, I wasn’t even aware of this journal.

    Mas E, Woodman RJ, Burke V, et al. The omega-3 fatty acids EPA and DHA decrease plasma F(2)-isoprostanes: Results from two placebo-controlled interventions. Free Radic Res. Jun 2010.


  125. Chris,

    You have not mentioned the omega3-index blood tests in your excellent fish oil posts. Would you agree that the following would be wise:
    – reduce dietary omega6 to a minimum, while taking moderate amounts of fish oil (or FCLO) for 6 months (to reverse years of SAD).
    – test your membrane fatty profile and either increase or decrease fish oil accordingly.
    – retest in 6-12 months and repeat.

  126. David,

    For depression, my recommendation is the same as it is for general health: the first step is to dramatically reduce omega-6 consumption. Then, eating fatty fish like salmon 2-3x/week and adding a moderate amount of fermented cod liver oil should help balance the n-3/n-6 ratio. That’s the intention behind fish oil, after all, but this is a safer way to do it.

    That said, if someone has done all that and they’re still not getting the results they want, and additional fish oil provides a benefit, I’d choose that over an SSRI any day of the week.

  127. TREMENDOUS article, Chris. I am so glad this information is getting out there. I always have felt the whole Inuits thing was based on some faulty assumptions. They eat whale blubber and meat, and this contains all the nutrients working in concert, not processed fish oil pills.

    Also as you say, the Maasai, Kitivans do fine without all the marine oils.

    Take care,


  128. JB: the 1g/d refers roughly to the total amount of polyunsaturated omega-3s. So it depends how much of the 1200 mg capsule is omega-3, not just EPA & DHA. For kids, “higher” dose refers to higher relative to their body weight, not higher in an absolute sense. So very young kids can take maybe 1/2 the adult dose, or a little less, and it will still be higher relative to body weight.

    Alan: yes, it’s the degree of potential oxidation and the fact that whole foods like salmon have more antioxidants.

    Ahrand: I agree completely.

  129. And once again Weston A Price is right, do not take ‘nutrients proven by science ‘ but take food proven by generations of healthy families : grassfed butter, liver, fish bone broths. We are not (yet) smart enough to determine exactly what nutrients in which combination have which advantages.

    Look at healthy populations and try to emulate and be vary wary of refined and extended shelf life foods.

  130. I know that you advocate eating fish such as canned alaskan salmon.

    The question I have is why can’t whole fish oxidize in your body just like fish oil? Or is it just the degree of potential oxidation! Does the whole fish have more antioxidants and greatly prevents oxidation.

    As usual, another great post. Thanks for your effort.

    • No one’s answered this one but my guess is that the whole form has antioxidants such as astaxanthin as you suspect. Some blogger once wrote that when he takes supplements, he also takes the whole food form for the complete range of antioxidants, potentiators, attenuators, co-factors etc.

  131. Chris,
    Thanks for the post very interesting. I have a couple questions. When you say 1g/d of fish oil are you referring to total fish oil or just the EPA/DHA? The fish oil I am currently taking is 1200mg capsule with 410 EPA and 274 DHA. Would you you be recommending 1 capsule (1200mg) or 2 (1368 mg EPA/DHA)? I also saw you recommended a “higher dose” for children. Do you have specific numbers for that? I have 2.5 and 4 year old boys.


  132. Oxidation will still occur. It’s a matter of scale. I believe the benefits of taking FCLO every day (vitamins A, D, K2, E & quinones in their naturally occurring form) outweigh the potential risk of oxidative damage, provided overall intake of PUFA is low and B6, magnesium, and other nutrients that support fatty acid metabolism is adequate.

    I’ve never heard of vectomega. One possible advantage of krill oil, as I wrote about in my article on fish oils in the EFA series, is that the omega-3s are in phospholipid form, which should be better absorbed. But my thoughts on krill oil in general are the same as my thoughts on fish oil.

  133. Hi Chris,

    a few questions:

    I am a newbie to Fermented CLO. Oxidation occurs both within and without the body. If CLO is fermented does this not allow oxidation to occur?

    What are your thoughts on Krill oil. Krill oil contains a natural antioxidant astaxanthin(?) inherent in its makeup and is presumably less susceptible to oxidative damage.

    I have been hot on the trail of this subject for about a month as well and have come to find a product by Europharma called vectomega. It is a “whole food” supplement of purportedly whole salmon heads pressed into a pill. The manufacturer claims that this phospholipid based form allows for easier assimilation and less oxidation. Are you familiar with this product?


  134. Craig,

    I am always learning and growing as a practitioner and a researcher. I try keep an open mind, consider other points of view, and change my approach when new information warrants such a change. I understand that this can be frustrating and confusing for those that come here hoping for answers.

    That said, the statement you quoted above doesn’t necessarily contradict what I’ve written in this article. I mentioned that fish oil has been shown to benefit those with pre-existing heart disease or those who’ve had a recent heart attack. Many people who take aspirin for cardiovascular protection fall into this category. Note that I was not recommending high dose fish oil supplementation in any of those previous articles, either.

    Also, I still do believe that taking 1-2g/d of fish oil is less harmful than taking aspirin. These aren’t black or white issues. For example, aspiring is less harmful than statins, but that doesn’t mean it’s benign. Likewise, high-dose fish oil is probably less harmful than aspirin, but nor is it benign.

    I do need to revise the series on EFAs to reflect this new information. Hopefully I can get to that in the next couple of weeks.

  135. This is an interesting sharing of ideas. The last few months I’ve been convinced that a “balanced fatty acid” pill with fish oil, borage, and flax seed is the way to go, but now I’m not so sure. I was unfamiliar with the idea of fermented cod liver oil – that sounds like its worth checking out.

    Fundamental to a lot of this discussion seems to be the issue of how badly screwed up an individual’s diet is to begin with before we try to modify it and/or supplement it. And also how much an individual can be motivated to change it.

    There are days when I feel on target and that I can be a good motivator of patients. On other days I’m not so sure. The secrets of being influential in how inspiringly we share information (not just on the technical correctness of our information) seems critical.

  136. I think people are going to get confused when they are told something is good, but then told it could be harmful.

    “I think fish oil is a much better choice than aspirin. Both have blood thinning effects, but fish oil has other benefits like balancing the omega-6 to omega-3 ratio and isn’t harmful to the liver.”

    Chris Kresser

  137. I think there may very well be a place for a “pharmaceutical” approach to fish oil. By that I don’t mean Lovaza, the drug company branded fish oil. I mean taking a short-term course of fish oil to accomplish a specific purpose, such as lowering triglycerides, or to reduce inflammation. The dangers I mentioned in the article seem to occur over a period of years.

    I highly recommend a paleo diet for fixing your lipid profile, if you haven’t done that already.

  138. No wonder people get so confused and give up trying to take the path to good health without the aid of the drug companies. I’ve been working hard to get my Triglycerides down without drugs through low carb eating, but felt like fish oil would be a big help. Now I am confused!

    • One of the posters here mentioned consuming macadamia nuts – I think these are the ones with monosaturated fat rather than omega 6 so much.

  139. Fish oil is not a quality whole food packed with good nutrients. Whole fish is, though. Which is why I suggest people meet their omega-3 needs by eating it instead of taking fish oil.

  140. Even if that means dropping or reducing quality whole food packed with very good nutrients? Sorry, I don’t agree with that :).

  141. Good post!

    But I need to consume 2 gram minimal a day of Fish oil because I eat 50 gram, sometimes more, almonds a day and 4 or 5 eggs. This alone is about 8 grams of omega 6 which I need to belance with 2 gram Fish oil. So in my case it wouldn’t be smart to supplement 1 gram I think?

    • Instead of having one source of oxidation, you created two sources by “balancing” the first source with a second one.

      If you want to eat nuts at that level, eat Macadamia. It’s monounsaturated and virtually no polyunsaturated fats.

  142. Vin,

    If only more supplement and drug manufacturers shared your integrity and concern for your customers’ well-being. Thanks for setting such a good example.

  143. Chris,

    I own and run a specialty fish oil company. So you’d think I’d be upset about your post. I’m not.

    Lately, we’ve been telling our customers to cut back on n-6 fats. We try to educate them on how to do this. The ‘reduce n-6’ message is on our blog, our emails, brochures and product inserts. Frankly, it’s bad business – I should be pushing more n-3, not less n-6.

    But it’s the right thing to do.

    To my customers, I’m their fish oil source. In my customer’s minds, it often does not compute why I’m asking them to eat less corn and soy oils. Our reduce-the-6 campaign is backfiring a little bit because it is like a car company asking people to ride bikes more often.

    Your readers are an elite bunch. They get it. But most regular people just want a pill to fix their problem – they don’t want to know what caused the problem. Some of my customers get it – and they love it! But for the others, we’re trying a slightly revised approach now: less n-6 = less n-3 pills = save money!

    They key is reducing n-6. As for oxidation, yes, it’s a problem. It’s a problem before the pills are made. It’s a problem while the product is ‘on the shelf.’ It’s a problem after consumption. This is not new. Double bonds have always caused problems. You will be reading more about this in the next few years – I know of some good research under way.

    I’m a nutritionist and my peers are not collectively ready to discuss this yet. Your post nudges us in that direction. But I hope people don’t skim your post’s title and conclude that fish oil is now to be avoided. The Paloe-elite can drastically reduce their n-3 pill consumption. But most Americans can’t. They’re drowning in n-6 and fructose.

    For now, I’d advocate less than 1 or 2 grams of n-3 per day. It’s a risk-benefit thing. In the meantime, those taking > 5 or 6 grams n-3 per day for years should expect some oxidative damage.


  144. I love it-sacred nutrition cows keep falling! We were so convinced of the benefits of Omega-3 supplements. Remember everyone saying we shouldn’t be afraid of fat, as long as it’s the good kind (omega-3)? I wonder what’s next? Vitamin D (it’s pedestal seems a little too high at this point)?

  145. Mike,

    Thanks for your comment.

    I agree that more research needs to be done here. In particular, we need to see how fish oil affects people whose intake of n-6 is already very low. Unfortunately, I doubt we’ll see a study like that anytime soon.

    Concerns about toxins in fish are overblown. I’ve written about that here.

    • No the dangers of heavy metal contamination cannot be understated. People should always steer clear of deep water fish. I’d go off on how ignorant that statement is but my comment would probably be removed.

      • Michael, give us a dietary alternative to eating deep water fish? Are we supposed to eat farm raised Talapia, which are raised in shallow plastic enclosures and fed commercial grain diets, loaded in Omega-6?

        The entire food chain is compromised. You cannot live your live engaged in phobias about possible contamination of food, because every food is compromised at some level.

        It’s all about intelligent tradeoffs. Deep water fish have insufficient contamination to avoid altogether, and they are a rich source of natural Omega-3 oils.

        If you are going to take the position that even small amounts of deepwater fish will result in compromised health, then prove this. Where is the peer reviewed research that shows correlation between deep water fish in diet and risk of death? I don’t think you can prove your case, and showing contamination of fish is not an adequate substitute.

      • Heavy metals are concentrated in the fish flesh. The levels in fish oil are negligible because metals are not oil soluble

  146. Chris,

    Great write-up, as usual; that first study you listed can be viewed in english via Google translate.

    As per my comments via Matt’s blog, the LDL increase is a positive result of fish oil intake: the shift from VLDL to LDL. This is in addition to the beneficial effect of lowered trigs:

    “Since the increase in LDL and consequently in total cholesterol levels appear to be due to the increase in the conversion of VLDL and LDL in the negative regulation of LDL receptor observed by other researchers. The increase in the concentration of LDL appears to be due to increase in size, which would be very favorable for the increase in the size of the molecule makes it less atherogenic (28,29).”

    “Our data showed increased oxidative stress observed by increased levels of MDA in 45 days of treatment, but there was no change in levels of hydroperoxides assessed by CLT. It was found that the QL is a more sensitive and specific than the TBARS and suffers less interference in the assessment of oxidative stress in patients with MS (35,36). Thus, it is concluded that ingestion of fish oil does not increase oxidative stress.”

    There still a lot to explore about fish oil, especially from a lipid peroxidization standpoint; I’ve personally seen too many benefits over the years to throw it out—myself, extremely low Tgs, elevated LDL and HDL, improved body comp to <7%, recued DOMS and increased athletic recovery, all at 6-9g/day EPA/DHA over the last 3 years.

    Had I had a massive amount of lipid peroxidatization going on, I would have suspected decreased health and performance.

    Whole food will always trump singular supplements any day of the week, but in the case of marine food, the source is extremely questionable at best.

  147. Another Dave: it is worth noting, but I’m not convinced by how researchers interpret their own data if their interpretation isn’t sound. I’ve seen so many studies clearly indicating that saturated fat or cholesterol doesn’t cause heart disease, for example, but the authors of said studies find a way of “interpreting” their data to support the dominant paradigm. This is a well-known phenomenon in medical research.

    Marilla: the advantage to fermented CLO is that 1) it is cold processed and thus the naturally occurring vitamins remain. Non-fermented CLO is generally heat processed, bleached and deodorized, which destroys the natural vitamins. Synthetic vitamins are added to compensate for this. 2) Fermented CLO has vitamin K2, which non-fermented CLO does not. That said, nonfermented CLO is still beneficial at a moderate dose. So continue with what you’ve got and then switch to FCLO.

    Theo: in this article I’m talking about the oxidation of omega-3 fats in the body – not during the production or storage of the fish oil, which is an entirely different issue. Even if you consume absolutely fresh fish oil, it’s still much more vulnerable to oxidative damage due to the fragile structure of the fatty acid – as depicted in the 2nd figure in this article.

    • I think it’s also important to note that the study was done on men with angina. Studies done on people with pre-existing heart conditions aren’t 100% applicable to healthy individuals. If an organ isn’t functioning properly from the onset it’s reaction to stimuli would be different than that of a healthy organ.

    • How do you feel about taking FCLO with butter oil, which is the version of the product that Weston Price Foundation advises to take? I guess this increases the vitamin k levels?

  148. chris,

    consumer labs is an independent lab that analyzes various OTC supplements for contaminates, listed ingredients, etc. Their more recent review of fish oil did not show any problems with rancid oils in the products they tested (with the exception of one fish oil product for dogs). Theoretically, there is a risk of rancid oils when taking fish oils, but it doesn’t seem to be as big of a problem as one might think. i agree we really need more long term studies with fish oil to give it a thumb’s up.

  149. What are your thoughts about CLO that isn’t fermented? My plan was to finish the full bottle I have (Healthspan) and then buy Green Pastures. Am I getting any benefit from the Healthspan CLO or could it be doing more harm than good? BTW, I’m eating a healthy diet with no processed foods, no seed oils etc.

  150. It is worth noting that the DART 2 researchers disagree with your interpretation of the results. From the paper: “An adverse effect of fish oil as distinct from dietary fish is unlikely.” There is a good discussion in the paper of some reasonable explanations for their results. They seem to think that the result may not be statistically significant but also bring up the possibility that the fish oil group may have engaged in riskier behavior or skipped their usual medications due to the belief that the fish oil pills were adequate. The study was an RCT designed to evaluate the efficacy of dietary advice, not of fish oil supplements, and thus should not be taken as evidence against fish oil supplementation.

  151. Obviously if they’re oxidized to oblivion they’re no good. I can’t help but think that the mixed results of fish oil supplementation have to do with the poorly abosrobed ethyl ester form. I just can’t see a bit of oxidation being worse than not being able to turn off eicosanoids properly. In either of those cases the data wouldn’t be a true reflection of better quality fish oil.

    And of course nobody is going to debate that some wild salmon is preferable to any fish oil. There is also the wonderful and very paleo option of BRAINS.

  152. Chris,
    Great article, you mention eggs, if you have  no access to pastured eggs, or even if you do, then fish eggs are a great choice, fish roe is a cheap source & I eat it once a week with the occasional kina ( sea urchin eggs ) . I think that fish eggs provide you with iodine.

  153. There is some data listed on FCLO on their website: http://www.greenpasture.org/retail/?t=products&a=test-data

    The levels of EPA and DHA are low, but as I said in the article, so are our needs provided we’re eating a healthy diet.

    I recommend FCLO over fish oil for everyone for the reasons I outlined above. The fat soluble vitamins play a large role in regulating the immune system – especially vitamin D.

    • How about if you live in a country with abundant sun year round like Thailand. Say you receive about 30 minutes of sun exposure each day, would that be enough for vitamin D purposes and would you still recommend taking fermented cod liver oil?

      Best regards, Stefan

    • Hi Chris,
      I’m wondering is there any danger of overdosing on vitamins A and D by taking cod liver oil daily and eating organ meats once a week or once a fortnight? And/or taking raw liver pills? Might this all be too much? Thanks.

      • Also, you mentioned fish oil is not shown to be beneficial in healthy people – is there more of a case for it in a not so healthy/recovering person? (Autoimmune issues)

  154. Thanks for the quick reply!
    My omega-6 intake could probably be reduced significantly, which is in the works as we speak. When talking about dosage for people like myself with RA, should I be taking FCLO or straight fish oil? FCLO does not disclose the EPA/DHA levels.

  155. I’ve been using Meriva-SR with inflammatory conditions like RA. It’s a slow-release curcumin bound to phosphatidylcholine, which improves absorption. I’ve never had much success with curcumin in the past, because it’s poorly absorbed and gets rapidly taken up in the bloodstream. This product addresses those issues and seems to work better.

    But, as with all autoimmune diseases, the key is balancing the immune system and addressing the underlying mechanisms.

  156. Young kids with rapidly growing brains have a greater need for DHA than adults, so I’d say continue with that dosage.

    People with autoimmune and other chronic diseases may also have greater omega-3 needs.  I guess my first question would be what is their intake of omega-6 like?  The first thing I would do is dramatically reduce that, before taking high doses of fish oil.

  157. Given your continued recommendation for Green Pastures FCLO, do you have any thoughts on dosage for children? Are 2 yr old has been taking 1/2 a teaspoon every since he could eat solid foods.

    Second question, does a person who currently takes high dosage of fish oil to relieve the symptoms of Rheumatoid arthritis have an alternative?
    Thanks in advance for any thoughts you may have on this.

  158. The algae oil is DHA, which is beneficial in moderate amounts.  You don’t have to worry about mercury, dioxins or PCBs in most commonly eaten varieties of fish.  See this article for more.

  159. I’m also curious about what those who can’t eat fish should do. My son has a potential fish allergy is is currently taking a soy free algae based DHA supplement. I also worry about my other sons eating a lot of fish due to contamination issues (plus they just don’t like it anyway). Suggestions?

  160. I’m on the side of limiting fish oil consumption and upping ones fish consumption. I think high levels of omega-3 are probably beneficial if you live in sub-zero conditions, but otherwise I believe the benefits of fish come from taurine & to a lesser extent magnesium.

  161. 400 IU is probably not sufficient to maintain levels in an area with little sunshine, so taking 2,000 IU is probably a good idea.  But the only way to know for sure is to test your levels.  “Test, don’t guess” sums up my strategy nicely on this – and many other issues as well.

  162. Chris,
    Thanks so much for this article. I had suspected this and wince when I hear about young healthy people taking back 15 capsules a day.
    Anecdotally, I switched to Green Pastures FCLO and I have to say it’s had much more of an impact on my health, no idea what’s making the difference as I always thought my diet was nutrient-rich.
    On that point, at this latitude (Ireland), do you really think the 400IU of D in the FCLO is sufficient? I do supplement with an extra 2,000IU D3, and I notice it makes me feel better and increases my resistance to colds. Am I harming my health in the long run doing this?

  163. Jake: thanks for your comment.

    I’m keeping an open mind about this, but your explanation doesn’t account for the increased levels of oxidative damage caused by n-3 intake as measured in the RCTs I mentioned in the article.

    Also, note that the studies do suggest that fish oil benefits patients with arrhythmia and chronic heart failure and/or a recent heart attack.  It’s possible that fish oil may benefit patients with heart disease, but not people that are otherwise healthy.

    FYI, there is an ox-LDL test available now outside of the research setting.  It’s offered by Shiel labs in NY.  Check it out here.  The problem with it is that they don’t have relationships with Quest or Labcorp, so you have to find a way to get blood drawn and then send it yourself.  I’m pretty sure you’ll need a doctor or health care practitioner to place the order, as well.

  164. I think that fish oil consumption is not about eating fish oil, it is about bringing your omega6/omega3 ratio to optimum level.

    My review of this fish oil trials is the dosage used is laughable low. So low that it could not have a positive effect on the omega6/omega3 ratio. That is why you are not seeing positive results in those trials. Also a friend who works in these type of trials says they use the absolute cheapest nutrients to test so the patients are getting crap-that also screws up the results.

    I test that ratio at least every 6 months and the only way I can bring my ratio close to 2 is 4.8 grams of fish oil plus being an absolute Nazi about avoiding omega 6 fats including not eating any nuts other than macadamia nuts.  By doing so I brought my ratio of omega 6 to omega 3 down to 2.7. Because I live in a rural area where good fish is not available, fish oil is my only choice.

    Also William Davis, the famed preventative cardiologist, has been treating thousands of very difficult heart patients with high doses of fish oil (and other things) for over 10 years. All the cardiologists in his region refer their hopeless cases to him.

    In that time he has had no cardiac events in the thousands of patients he has treated for a decade. That means: no stents, no bypass surgeries, no heart attacks and no strokes. He had one person die because he lost 5 close relatives in one year. In addition he is seeing arterial plague progression halted or reversed in most of his patients.

    What is needed is to move the oxLDL test out of the lab and into the hands of the public so this issue can be settled for each person. In the meantime, I have climbed aboard the optimum omega6/omega3 train and I am riding until that test is available. Although I am doing the absolute certainty test by getting a heart scan in the spring.

    • Jake, by comparison to a Paleo period caveman diet, modern diets overdose us with about 30 times as much Omega-6 as we actually need.

      The solution to that problem isn’t to take 30 times as much Omega-3 as we need, to “balance out” the massive overdose of Omega-6. All that would do is give us 60 times as much polyunsaturated fatty acids of both types as what our body needs, and much of that might increase risk of oxidation in LDL.

    • These trials never tell the truth because they use “nutrients” that are lab-made; never found in nature.
      In fact, all these trials using low-quality, isolated, synthetic substances should be banned, because people start commenting and drawing conclusions based on these
      faulty trials, causing confusion.
      The commentators should be more responsible, and check to
      see if the trials are conducted using, high-quality, natural, found-in-nature nutrients, and substances.

  165. Chris: liver is a no go! gag, but I loves me eggs. I’m good on the other nutrients too. It’s also important for folks to remember that too much n-3 is bad too as those fats compete with the same enzymes as n-6, just as an excess of n-6 can inhibit n-3 elongation, excessive n-3 (especially EPA I’ve read) can interfer with AA elongation…that step is there for a reason ya? All goes back to balance.

  166. Doug: consumption of AA-rich foods (liver, egg yolk, etc.) as well as a nutrient-dense diet with adequate levels of B6, biotin, calcium, magnesium and other co-factors will protect against any potential toxicity from EPA.  So yes, I think you’re doing just fine.

  167. i think fish oil can effectively ameliorate an omega 3 deficiency which a lot of people get into thanks to our high veg oil diets otherwise known as SAD.  but if you correct a deficiency and start eating right at the same time, ie, limiting veg oils, eating more meat less carb and so on then i think that is when fish oil becomes counter productive.
    this would explain short term results seen in abbreviated studies right?

  168. Hi

    If 1 tsp (about 4.5g) has ~ 500mg DHA +/- and ~ 300mg DPA +/- and fatty fish can have about 4-5g (total) per 200g/7oz serving, then 1 tsp of cod liver oil daily and 2 servings of fatty fish (assuming 200g per serving, which isn’t a lot) provides on average 2g+ total EPA/DHA. To your point, many healthy, and long-lived peoples do not consume a lot of marine-based n-3. I’ve been taking too much no doubt, and so as not to drive myself crazy with calculations etc. If I get about 1-2g per day, I’m doing well I figure (given I’ve cut out the n-6 sources etc)


  169. Julie: I still recommend fermented cod liver oil for that, for the reasons I stated at the end of the article.

    kg: possible, but even studies with fresh EPA & DHA have shown that it increases oxidative damage (at least in rats).  This isn’t surprising when we consider the structure of omega-3 polyunsaturated fats.

  170. Chris,
    Is it possible that the fish oil used could taint the results? Considering that there appears to be a lot of pretty bad supplements out there, containing PCBs, it makes me wonder if the actual brand used has an effect on the results. I have been to taking Omegabrite for a while now. Sure hope it hasn’t been doing more harm than good…

  171. Thank you.  What would you recommend as the best way to maintain a healthy level of vitamin D in the body? (I live in New Hampshire, sun is scarce many months of the year.)   I may have missed this somewhere in other posts.

  172. Another great post on the possible dangers of gulping down high doses of fish oil supps.  I recently had a brief post about this here : http://abundantbrain.com/2010/10/omega3/ and linked to your stuff regarding animal vs. plant sources of EPA/DHA and the fish oil buyer’s guide.  I have long been skeptical of the studies of isolated nutrients not part of a mixed whole foods diet- especially for essential fatty acids which must go through several biochemical conversions and will be affected by the digestive/metabolic environment.  The Kuipers, et al. paper makes some excellent points.
    What does concern me though is the realistic fact that nearly everyone in the U.S. and many other places gets too much omega-6 EVEN those who are cognizant and try to limit the dose.  It’s just so ubiquitous.   I’m curious as to your recommendations for adequate dietary omega-3 for those who do not eat seafood due to allergies or other reasons.

    • Preston, it’s true we are all drowning in Omega-6 PUFAs. It’s also true that Omega-3 and Omega-6 should be closer to a 1:1 ratio. But what I take away from the articles here is that the solution is NOT to massively increase your dose of Omega-3 to compensate for the massive overdose of Omega-6. All that would result in is two massive overdoses of PUFAs, and they are both dangerous when taken above the biological need.

      The real advice here should be get rid of as much polyunsaturated fat as possible from ALL oil-based sources. Ensure baseline needs of Omega-3 from whole foods.

    • Jay, I was trying 500 mg of krill oil as well, but have you opened a jar of that stuff and smelled it? Mine smells really rancid, way beyond just fishy smelling.

      And the point I am starting to takeaway from Chris’ source articles is that we just get too much polyunsatured fat in our diets. It’s being added into every commercial food. It’s in olive oil and most monounsaturated oils. It’s in trace quantities in lots of foods. Our actual biological needs for Omega-3 and Omega-6 are not large and anything above the baseline need appears to do more harm than good.

  173. You are so right, too much PUFA is bad and an omega 6/3 ratio that is or too high or too low is bad. Furthermore do fish oil supplement provide too much EPA in relation to DHA. Just limit your omega 6 intake and eat fish a couple of times per week.

  174. Chris, A big thank you for this article.  I have been seeing hints of this elsewhere and now the details.  I have been concerned about fish oil supplementation for one simple fact — most of the brands contain soy oil.  I know that soy is poison and I am trying to reduce my intake of soy and since it seems to be in ALL refined foods, it is hard.  It seems ridiculous to take something that is supposed to be good for you and then back load it with an extremely harmful oil even if it is a binder.  I have also seen Vitamin D supplements with soy in them.  Very disturbing.

  175. Good article, Chris.  Bill, that’s not true — read the Cochrane Review, for example, and you will see that they spend an extraordinary amount of time critiquing the methodologies of the original studies and in fact a large portion of their statistical analysis was aimed at taking into account methodological differences between studies.


    • I will be revising my recommendations from that article. The problem with ALA is that less than 0.5% of it gets converted to DHA, which is the essential fatty acid we’re most concerned about. Rather than supplement with oils, I’ve always suggested the best course is to reduce omega-6 and eat fatty fish 2-3 times a week.

      • Hi Chris,
        Thanks for your article – well written and informative. What would you recommend vegetarians do for omega 3/6 balance? I’ve been eating chia seeds and flax seeds to help this – do you think that is enough?

      • I’m curious if you’ve done any research on the effects of fish oil during pregnancy for the health of the Baby? I’m really clueless about this and not sure even where to start reading? Any help would be great!

  176. Unfortunately these are metas which means that the original methodology cannot be critiqued. If most of these folks were taking rancid fish oil, I would almost expect these results. Almost all fish oil in capsules is (potentially) rancid off the shelf.

    • Bill,

      Most of the studies I mentioned were RCTs. The 4-year DART 2 trial which showed an increase in heart disease and mortality was an RCT. The trial showing an increase in oxidative damage from omega-3 consumption was an RCT. The trial showing an increase in MDA and lipid peroxide with 6g/d of fish oil was an RCT. The only trials that were meta-analyses were the Cochrane study and the review of fish oil trials lasting longer than one year.

  177. 3g is quite high, actually.  A 6 oz. portion of salmon contains about 1 gram of DHA.  In any event, the point of this article is that there are no studies (that I’m aware of) showing any benefit of fish oil supplementation for healthy people, especially at doses >1g/d and especially over the long-term.

    • Chris, thanks for the article. For now I’ve changed my beliefs and understandings around fish oil supplementation from this and other articles.

      Please can you clarify though, when above you say doses of more than 3g/day is quite high, you are reffering to the amount ot EPA/DHA right? Or the dose of fish oil? It’s possible Wilmar may have been referring to 3g day of fish oil which would have much less EPA/DHA in it.

      One problem I’ve found is it’s sometimes been unclear in several of the articles/studies I’ve seen whether they are talking about grams of fish oil or grams of EPA/DHA.

      The cod liver oil I have been using has approx 1.5g EPA/DHA in 10ml of cod liver oil (around 9 or 10g). This is the recommended dose. I find it hard to take for more than a few days at this dose, although I was taking double this dose intermittently a few months back. I’m now attributing it to some of the bad symptoms I’ve been getting recenty; dizziness on standing, pins and needles/tingling (induced vitamin E deficiency?), worsened vision, worsened fatigue and I hadn’t made the link, think it’s time to stop

    • Hey Chris –

      I just came across this article after reading your most recent one about scientific studies. I’m surprised (sort of) by this. I say sort if because I’ve always suspected that most fish oil supplements go rancid while in transport (hot trucks with no air conditioning).

      But up until reading this article, all if the research or articles I’ve ever read or heard of about fish oil is that it is great for you short and long term. Robb wolf (and several other influential names in the paleosphere) even recommends supplementing with 2 or more grams per day.

      Coincidentally, I recently tested my lipid peroxides and they are elevated. I have been taking around 4g of fish oil per day for about a year.

      So my questions are:

      1) I see this article was from 2010. Is this still your stance?

      2) wouldn’t cod liver oil go rancid at the same rate as fish oil? So even though it is packed with vitamins, why recommend it?

      • Hey Rick, I just wanted to address your second question because I see that Chris is recommending fermented cod liver oil. Fermented foods in general, I know can last several years without going rancid (how ou ancestors could eat foods out of season before refrigeration). I can only assume fish oil is te same when fermented. Non fermented fish oil on the other hand, you are probably right about. Also, if it is not fermented it would not contain vitamin K, and likely fewer vitamins in general. I wonder if Chris would say non fermented oil’s vitamin benefits outweighs any risk (I’m assuming not).

    • Chris, I read this and your other article. I’m very impressed. One quick question: What to do if I absolutely can’t and won’t eat any kind of fish? Won’t a “whole” fish oil supplement, something which contains the natural ratios of all omegas, 3, 6, 9 etc… as found in pacific salmon, be a reasonable compromise? Are all fish oils unstable and possibly damaging? I’m taking something made from purified wild Alaskan salmon oil, which is 3rd party certified and which contains 3, 5, 6, 7, 9 omegas. It’s made by Nordic Naturals. Won’t this be a good compromise for someone who doesn’t eat fish?

    • Dear Chris I have been taking 6 x 1000mg of fish oil for years im 42 and was diagnosed with severe dry eye and meiobian gland disfunction a year ago after taking the pill for perimenopause. I was off the fish oil for several months when I got the dry eye. Doctors tell me to keep taking it ive just come accross your information and im concerned im doing more damage than good. I need to try and keep lipids healthy in my eyes and inflammation down should I just switch to cod liver or just keep on with fish oil and how much would you recommend.
      Or should I take both.

      kind regards Bianca

      • Bianca-
        I am in the same boat as you. 40s, meibomian gland dysfunction & dry eye. Been taking more than 3g of salmon oil per day per drs orders. After this article, I’m going to follow Chris’s advice and try eating salmon 2x week and limiting my omega 3s to the amount that’s in HydroEyes. I’m scared now. Been taking high dose one has for 2.5 years.

    • Guess you’re feeling pretty silly now especially after the Virgin’s saved their son by giving him 20 grams of fish oil a day. Oh, and the doctor saved the coal miners life by giving him 18 grams of fish oil a day in his feeding tube. Seems like high doses of fish oil is key in repairing the brain.

      • You cited two extreme cases where fish oils were given at therapeutic doses to heal severe, life threatening injuries, on a relatively short term basis. The crux of the argument presented is that there are no studies where high doses of fish oil is proven to be healthy on a LONG term basis. Apples and oranges.

    • I came upon this page while researching how much oil to consume for recent heart patients, and was stuck by the similarity of your conclusion regarding long term usage of fish oil capsules, and my recent heart problem circumstances.
      I have been taking fish oil capsules for almost 2 years now, first year was 2000 mg a day, and 2nd year 1200 mg a day. Now I recently had a heart problem this month, luckily I survived ( and have not taken any fish oil caps since). But based on my young age and other circumstances, I strongly agree with your conclusion about too much fish oil or omega-3 and its link to increasing heart disease. I know you are looking for some evidence to support your conclusions, and maybe I can help you. Let me know on my email if you need.

  178. I think I can stand behind suggesting eating fish over taking fish oil, but in the event that you’re not gonna have fish that day, would a 3-gram dose of fish oil be a gross overestimation of the fish oil content you’d consume from eating a serving of whole fish?  Without being overanalytical that kind of seems like not that much fish oil.  I’d be more worried about the 10-20g/day dosers.

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