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The Fish vs. Fish Oil Smackdown


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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.

So far in this series we’ve looked at why fish is superior to plant-based sources of omega-3. We’ve examined the importance of reducing consumption of omega-6 fats. We’ve considered how much omega-3 is needed to support health and treat disease. And we’ve revealed that concerns about the safety of fish consumption have been overblown, and that eating fish regularly is not only safe, but incredibly beneficial.

In this article we’re going to compare fish with fish oil as a means of meeting our omega-3 needs, and for overall health and wellness. The comparison will be based on the following criteria: nutrient content, potency, absorption, cost and environmental impact.

Fish oil has become wildly popular in the last few years, as people increasingly understand the importance of omega-3 in the diet. However, part of the reason for fish oil’s popularity is related to concerns about the safety of eating whole fish – concerns that we now know are unfounded.

With this in mind, let’s see whether whole fish or fish oil are the best choice for most people.

Nutrient content

Fish: contain not only EPA and DHA, but also vitamin D, selenium, protein, co-factors and a more complete fatty acid profile than fish oil. Selenium, in particular, is important because it protects against mercury toxicity. Vitamin D protects against nearly every modern disease plaguing us today. A 6 oz. portion of wild salmon contains 1,700 IU of D, which is difficult to obtain in that amount from other dietary sources.

Fish oil: most oils contain only EPA and DHA, although salmon and cod liver oil also contain moderate amounts of vitamin D. Fish oil has a more limited fatty acid profile than whole fish, and doesn’t contain selenium.

Potency (levels of EPA & DHA)

Fish: a 6 oz. portion of wild salmon contains 883 mg of EPA and 1,111 mg of DHA. 2-3 servings a week of salmon, combined with a low intake on omega-6, would be adequate for most people.

Fish oil: this is where fish oil may have an advantage over fish.

Because it is molecularly distilled and purified, fish oil can have high concentrations of DHA and EPA. 6 capsules of Jarrow Max DHA would provide 1.5g/day of DHA, a level that would be difficult to obtain from eating fish.

You’d have to eat approximately 8.5 ounces of wild salmon every day to obtain that much DHA.


Here’s where things get a bit tricky. I talked about potency above, and mentioned the levels of EPA and DHA in both fish and fish oil. However, those levels mean very little unless we consider how well they’re absorbed.

Several studies indicate that fish oil supplementation is not as effective as epidemiological evidence on the benefits of fish consumption suggest it would be. It appears that the presence of other fats in the fish activates processes required to absorb the EPA and DHA properly. This explains why the EPA and DHA are better absorbed from eating whole fish than from taking fish oil.

In one study comparing the effects of fish and fish oil, researchers found that levels of DHA after 6 weeks of salmon consumption were nine times higher than after fish oil administration.

The authors hypothesized that the configuration of fatty acids in whole fish is familiar to our body and thus easier to absorb. Conversely, the fish oil alone doesn’t adequately activate the process of fat absorption required to assimilate the fatty acids.

Another study confirmed this by demonstrating that fish oil is absorbed much better in the presence of a high-fat meal. They found that the content of n-3 fatty acids in the body tissues rose dramatically when the fish oil was taken along with 12g of olive oil.

We can draw two conclusions from these studies:

  1. EPA, and especially DHA, is much better absorbed from fish than fish oil. The effect may be as great as nine-fold. This means that we would need nine times less DHA from fish to obtain the same amount of DHA from fish oil. Put another way, we’d need nine times more DHA from fish oil to obtain the same amount of DHA from fish. So, using the 6 oz. portion of salmon as an example, with 1.1g of DHA, we would need to take 9.9g of DHA from fish oil – roughly 36 capsules/day of the Jarrow Max DHA – to obtain the same amount of DHA we’d get from the salmon. That’s a lot of fish oil!
  2. On the other hand, taking fish oil capsules with a high-fat meal can greatly improve their absorption, to the point where they may be on par with whole fish. (I say “may be” because the scientific literature is mixed on this.) This is likely due to the effect described above, where the presence of other fats activates the body’s fat absorption mechanisms.

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This is also tricky to compare, since prices and availability of fish vary regionally. A straight comparison of the cost of DHA obtained from fish and fish oil also ignores other important factors, which we’ve already discussed above, such as the presence of other nutrients and the differences in absorption.

Let’s assume for the sake of comparison that fish oil is taken with a high-fat meal to improve absorption and that absorption rates of EPA and DHA are roughly similar between the two. Let’s assume that wild salmon is available for $13/lb. (I know it is much less in some areas, and much more in others).

Let’s assume also that we’re shooting for a daily intake of 500 mg of DHA.

To obtain this amount of DHA from salmon, you’d have to eat just over one pound per week (19 ounces). That would cost you $15.45.

To obtain this amount of DHA from Jarrow Max DHA, you’d have to take 2 capsules per day. Assuming you bought a bottle of 180 capsules from Vitacost for $14.70, you’d pay just $1.14 for the same amount of DHA.

However, you’d have to consider the following caveats:

  1. It’s uncertain whether, even with a high fat meal, you’d be absorbing the same amount of DHA from the fish oil as you would from the salmon
  2. The salmon has large amounts of protein, selenium, vitamin D and other fatty-acids and co-factors that the Jarrow fish oil doesn’t have
  3. Other oily fish that are significantly cheaper than salmon, such as sardines and mackerel, are also very high in EPA and DHA.

Environmental impact

Overfishing and fish farming have already seriously damaged the health of marine ecosystems, and threaten to do even more damage if fish and fish oil consumption increases.

Much has been written about this elsewhere. Charles Clover’s The End of the Line: How Overfishing is Changing the World and What We Eat provides a particularly astute (and scary) analysis of the impacts of current methods of fishing on global ecosystems.

In short, I believe the most responsible choice we can make is to limit the fish we eat to those certified by groups like the Marine Stewardship Council (MSC).

However, even those groups are not infallible. Recently concerns have been raised over MSC’s decision to certify a salmon fishery in British Columbia where the salmon population is declining rapidly. Environmentalists and scientists have protested the decision, but the MSC seems to have moved ahead regardless.

Unfortunately it’s not a cut and dry issue, and those who are interested in eating fish harvested in a sustainable matter will have to do their own research and stay abreast of changing policies and practices.

In general, though, most environmentalists and scientists support the MSC certification. MSC has a list of fish they consider safe to eat on their website, which you can refer to.

MSC also has a certification label (pictured below) they provide to vendors of MSC-certified fish that you can look for when you’re shopping.

The sustainability of fish oil production is even more difficult to gauge. Some oils are produced as a byproduct of fish harvesting, and manufacturers claim that they are simply making use of something that would normally be discarded. While this is certainly better than harvesting fish solely for their oil, it still supports harmful fishing practices.

The safest bet is to only use fish oil that is made from fish that are certified by MSF or a similar organization, such as the Environmental Defense Fund. Vital Choice Wild Salmon Oil is one example, as is Jarrow Max DHA (which is made from anchovies and sardines, both of which are generally regarded as safe to eat from an environmental standpoint).

The verdict

The question of whether fish or fish oil is a better choice is complex and depends upon several different factors. These include whether DHA is needed for maintenance or therapeutic effect, access to sustainability caught wild fish, financial considerations, and the presence of other nutrients in fish.

For those who are generally healthy and want to stay that way, I think reducing omega-6 consumption and eating a moderate amount of oily fish (2-3 6 oz. portions per week) is the best choice. This will get you plenty of EPA & DHA along with high quality protein, selenium and vitamin D. If wild salmon is out of your price range, mackerel and sardines are both high in EPA and DHA and certified by the MSC as safe to eat.

For those who have a chronic, inflammatory condition such as cardiovascular disease or an autoimmune disorder, I would recommend a combination of whole fish (perhaps the same 2-3 6 oz. portions per week) along with a high quality fish oil. This ensures that you are getting the benefits of whole fish along with the added therapeutic effect of higher doses of DHA and EPA. Somewhere around 1.5g per day of DHA would be a good therapeutic dose, which would mean taking 1g/day of DHA in fish oil capsules in addition to the three 6 oz. portions of oily fish.

In the next and final article of this series, I’ll discuss the criteria for choosing a fish oil and make recommendations based on those criteria and clinical experience.

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Join the conversation

    • Watch documentary “Salmon Confidential” and then you’ll understand better the state of our fish farm/wild caught industry.
      Mind Blowing Documentary!

      • Mind Blowing is looking into the credentials and motives behind the “documentary’s” creator. It is a shame such flare is put into misinformation to capture the publics attention instead of presenting credible and accurate material on an important industry. Could the industry improve? YES, but it is a necessary industry and one that strives for continuous improvement, the same as other food industries.

  1. Fish is safe???? Is that suppose to be a joke? Is consuming plastic safe? What about the chemicals that build in the larger fish such as tuna? Not to mention the BPA that most containers have…

  2. So unfortunately I have a chronic, inflammatory condition. inflammation on the joints caused by arthritis(RA) been taking Advil for the relief for quiet a while now and I stumbled on your previous article about Omega 3. For the past couple of months i started taking these Omega 3 supplement derive from fish oil(http://visiongroupcorp.com/omega3.html), My rheumatologist suggests 3g max daily intake(taking to gel caps/day). My wife is cooking loads of fish almost every meal and the never ending salmon sandwich for breakfast with sprinkled chias, I aint complaining coz it helps keep the condition of arthritis at bay. But I was wonderin is, would I already be taking enough from the supplement and too much with the daily fish meal? That I can probably tell my wife to Include some steak on the menu at least once a week(or twice) and tell her hey Chris told me I’m taking too much Omega 3 that any more and i’ll transform into a merman… 😀 Thanks Chris!

    • I know this wasn’t your question, but a lot of inflammatory conditions can be helped by avoiding foods that increase inflammation in your digestive system. Gluten is a prime example, lactose and other dairy products too. Have you considered trying to incorporate that into your diet too? Hope it helps!

    • Let me expand since you pretty much answered that question in your article.. I am trying to think of a way to produce fish oil in a more sustainable manner because scientific research is showing that fish oil pills as a dietary supplement for human consumption is a growing industry.

  3. Chris, which one has higher omega 3 content, sardines canned in water or in oil? I’m looking up but can’t find if sardines canned in water have good amounts of omega 3. Could you help with this? Thanks.

    • Good question. I know I am not clear on the oil that sardines are canned in. good? bad?

      • Matt – I always insist on Extra Virgin Olive Oil (the same when I buy tinned mackerel). I then save the oil to use in salad dressings or for pouring over cooked vegetables. I trust Chris would agree with me, but perhaps he will let us know.

    • I have seen John West canned Canadian sardines in Spring Water. This is available in NZ so I am sure you could get it in other countries.

  4. Does a small drink – like 30 ml of brandy or 60 ml of wine improve absorption of fish oil[esp the liquid version ] ?Alcohol is supposed to dissolve fat.

  5. What if you took your fish oils supplement with a meal containing fish? Would this help with the absorption of the supplement?

  6. Are there concerns about lipid peroxidation and canned fish like sardines or herring?

    • Marge, you have asked a good question, as have others here. I wonder when we are going to get some answers.

  7. When considering cost, consider this. You don’t have to take a fish oil supplement, but you have to eat. You are already spending money on dinner, why not spend it on salmon instead of steaks. Do this a couple times a week and it’s really costing you little, if and extra money to eat fresh, wild caught salmon and get your omega 3’s from a whole food source.

  8. Hi Chris, I enjoyed your article, and think its great your spreading the word on the benifits of fish and increasing consumption as part of a healthy diet! It’s so important and such an easy thing to do for ourselves to contribute to a healthy lifestyle. I noticed that you specifically name wild fish as dietary sources, and as we all know wild capture fisheries are on decline for many species and it would be worth pointing out farm raised and sustainably grown fish are excellent sources on par with wild caught Omega content, as recent research has shown. It is also the more environmentally concious choice for some fish such as Atlantic Salmon as farms have minimal environmental impact while reducing pressure on wild stocks.

    • Watch “Salmon Confidential” documentary online, and then comment to whether fish farms harm wild fish.

  9. Chis to Robb’s defence he does make 3 recommends of fish oils in his book and I think he has made some on the podcast as well.

    Chris COD, FCLO, Nordic Naturals, Mercola krill & Salmond oil(same as Vital) all seem to make cracking in my boones worse, do you have an explanation for that? That is the very same reason for me to take it in the first place. I do eat a low carb paleo diet & the carbs I do eat coming post workout

  10. Am I too late to ask whether there is any goodness left in canned salmon (wild-caught Atlanitc) and tuna except protein?

  11. I have a serious IgE allergy to all things seafood. Even fish oil capsules. What is my best course of action?

  12. I love fish but don’t understand the benefits of eating it. All fish I eat is COOKED. Don’t the Omega-3 fats and other good things in fish get oxidized or corrupted when heated??
    Please, can Dr. Kresser or somebody clarify this? This has bothered me for a while.
    Thank you.

  13. Hi Chris,
    I have seen a TV show where some MD claimed that EPA and DHA compete between themselves, so he suggest to get different capsules (one only EPA and the other only DHA) one in the morning and the other at night in order to mitigate this compete problem.
    Any thoughts about this?

  14. hi chris,

    are you familiar with professor brian peskin and his theory that fish oils are very harmful? he says we should get our omega 3s from the parent essential oils, from plants, and that our bodies convert them to DHA and EPA in the amounts that we need. http://www.brianpeskin.com/
    i’m pretty confused about this, because other natural health “gurus” agree with him. i’d love your opinion on this. thanks.