Important Update on Cod Liver Oil
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Important Update on Cod Liver Oil


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An independent analysis of Green Pastures Fermented Cod Liver Oil suggests that it may not live up to its claims. But is the analysis sound? Get the nitty gritty details and my recommendations.

best cod liver oil
One of the best ways to get a daily dosage of cod liver oil is in capsule form. obewon/iStock/Thinkstock

As many of you know, I’ve long been an advocate of cod liver oil. In addition to being a good source of long-chain omega-3 fats like EPA and DHA, it’s rich in vitamins A and D, which are difficult to obtain elsewhere in the diet.

For several years I’ve recommended Fermented Cod Liver Oil (FCLO) from Green Pasture. I took this product myself, and my wife took it throughout her pregnancy and while she nursed our daughter, Sylvie. I recommended it to my patients, readers, podcast listeners, and friends and family.

About a year ago, I received an email from a new company called Rosita Real Foods regarding a new cod liver oil product (called Extra Virgin Cod Liver Oil, or EVCLO) that they were bringing to market. Leading up to the launch of their product, they sent out a series of emails explaining how it is manufactured, processed, tested, and produced.

I was impressed by their transparency: they provided test results for fatty acids, vitamins, dioxins & PCBs, rancidity, and oxidation by-products on their website, along with a list of institutions that performed the testing as well as the dates of the tests.

As soon as the EVCLO product became available, I ordered some. I noticed right away that it smelled, looked, and tasted fresh. This, together with Rosita’s transparency and third-party testing, was enough to convince me to switch over to EVCLO and begin recommending it to my tribe.

Independent Analysis of Green Pasture Fermented Cod Liver Oil

Last weekend I received an email from Kaayla Daniel, a nutritionist who has been involved with the Weston A. Price Foundation (WAPF) for many years. She had grown increasingly suspicious of the Green Pasture product recently, and she requested that the WAPF conduct independent analysis of it to determine whether it lived up to its claims. The WAPF voted not to conduct this testing, so Kaayla took matters into her own hands.

My take on the recent report on Green Pastures Fermented Cod Liver Oil.

The result is a 110-page report with test data from multiple independent laboratories both in the United States and abroad with expertise in testing marine oils and nutrient levels. You can read the full report for free here. But in short, these were the conclusions from her report:

  • One of the three batches of FCLO that were tested was found to be rancid, based on free fatty acid values.
  • Levels of vitamins D, A, and K are lower than Green Pasture claims on its website.
  • DNA testing of the livers purportedly used to make FCLO suggests that it is not made from cod, but from Alaskan pollock. Oils from Alaskan pollock liver have a different nutritional and fatty acid profile than those from cod livers (which explains the next finding).
  • While all other cod liver oil products contain more DHA than EPA, FCLO contains more EPA than DHA. This EPA-to-DHA ratio is consistent with what you would find in Alaskan pollock liver oil.

Kaayla’s report certainly raises a number of issues that deserve attention. However, I do have some concerns about the data she presents. They arose out of research I did over the weekend, as well as discussions with colleagues in the fields of biochemistry, nutritional science, and lipid science.

Are the Fat-Soluble Vitamin Tests Results Reliable?

Testing for fat-soluble vitamin levels is incredibly complex and not yet standardized. I am concerned that the approach to quantifying them in Kaayla’s report was oversimplified. This is based on communications I’ve had with Dr. Chris Masterjohn, a nutritional scientist and an expert in fat-soluble vitamins.

Chris has noted that there are likely at least half a dozen (if not more) vitamin D compounds in cod liver oil, and it may be that the preponderance of biological activity comes from compounds other than vitamin D3 or D2. (This is the case with cow’s milk, where most of the vitamin D activity comes from 25(OH)D and very little comes from vitamin D.)

In fact, one vitamin D expert has remarked that a scientist could spend an entire career simply characterizing the factors responsible for the vitamin D activity in cod liver oil. Clearly there’s a lot more to this than comes across in Kaayla’s report.

This may explain why Dave Wetzel, the owner of Green Pasture, has been attempting to quantify the fat-soluble vitamin content of FCLO for many years but has never been entirely successful. It seems that there are many different vitamin-D-like or vitamin-K-like compounds in FCLO (and other cod liver oils) that cannot be easily measured with current analytical methods. Measuring the biological activity of vitamin D compounds by feeding the substance in question to rats may be a better method of determining vitamin D content than quantifying the levels of D2 and D3. (Green Pasture did this kind of testing in 2009, and the results indicated that FCLO contained roughly 400 IU of vitamin D per tsp, which is in line with what you would expect for cod liver oil.)

Is FCLO Really Rancid?

If FCLO were truly rancid, we would expect to see very low levels of EPA and DHA in the oil. Once fatty acids (like EPA and DHA) undergo peroxidation, they cannot be regenerated from their peroxides. However, on page 102 of Kaayla’s report, the lab results show that FCLO has approximately 315 mg/tsp of DHA and 685 mg/tsp of EPA, for a total EPA/DHA content of 1,000 mg. According to Rosita’s website, EVCLO has approximately 1,200 mg of EPA/DHA combined. So, while the batch of FCLO tested in Kaayla’s report contained less EPA/DHA than EVCLO, it still contained a substantial amount—which would not be expected if the oil were rancid as claimed.

The claim that FCLO is rancid was based on high levels of free fatty acids found in the oil. Kaayla suggests that this is an accurate way to determine rancidity in marine oils. However, according to most lipid scientists, hydrolysis of triglycerides and other esterified lipids into free fatty acids is completely unrelated to oxidation and is therefore not an accurate measure of rancidity.

Instead, TOTOX, anisidine, MDA, and TBA/TBARS are better indicators of whether an oil is rancid. In Kaayla’s report, FCLO received good scores from all of the labs on TOTOX, and all but one lab (which was not able to obtain a result at all) on anisidine. Two of the labs reported normal TBA values. One lab reported a TBARS value that was high, and another reported an MDA value that was 10 times higher in FCLO than in other cod liver oils.

These results are somewhat mixed. The majority suggest that FCLO is not rancid, while two of the test results suggest that it is. I think more investigation is needed on this before any firm conclusions are drawn.

Variability in Test Results from Lab to Lab

There was significant variability in test results from lab to lab and test to test. The samples Kaayla sent in for testing had manufacture dates ranging from 2012 to 2014. It’s conceivable that Green Pasture changed its production methods during that period of time, which could explain the variation in the results.

Another possibility—and one that is likely—is that the variability is at least in part explained by different methodologies and techniques used by different labs. Unfortunately, this is difficult to verify and investigate further because Kaayla was not able to name the labs in her report (due to legal agreements).

Though this seems to be common practice in this field, I feel that the omission of the names of the labs that performed the analysis weakens the reliability of the findings. Given the known complexities involved in this kind of testing, as well as the variability between labs, it’s unfortunate that we can’t ascertain which lab did which tests. This isn’t a criticism of Kaayla, because I imagine it was beyond her control, but I do see it as a downside.

Summary and Recommendations

Kaayla’s report does raise some concerns, but clearly there is a lot more to it than initially meets the eye. Rather than viewing her report as the final word, I hope that it’s the spark for an informed and forthright investigation into the issues that she has raised.

Green Pasture has issued a preliminary response here. Interestingly, it makes some of the same points I have made in this article (that biological activity may be a better measure of vitamin D content than quantifying D2 or D3 levels, and that free fatty acids are not an accurate measure of rancidity in marine oils). They are also working on a more detailed response, which I look forward to reading.

One of the lingering issues that Kaayla raised in her report is the finding that the livers used to make FCLO were not from cod, but from Alaskan pollock. I certainly hope Green Pasture addresses this in their upcoming response.

Frankly, I feel that I don’t have the information I need to make a clear decision about whether to continue recommending FCLO. I am in touch with several people with expertise in marine oils, lipid science, and nutritional biochemistry in an attempt to better understand the implications of Kaayla’s report. I will report back to you as I learn more.

In the meantime, I do feel confident in recommending EVCLO from Rosita Real Foods. As mentioned above, they are transparent about their manufacturing process, they post independent lab results (including the names of the labs that performed the tests) on their website, and their product smells, tastes, and looks fresh. They also have an extensive FAQ with answers to many questions about their product and process.

How Concerned Should You Be If You’ve Been Taking Green Pasture FCLO?

Kaayla’s report identifies some issues that deserve further attention, including lower-than-reported levels of vitamins A, D, and K, possible rancidity, and a different ratio of EPA to DHA than would typically be found in cod liver oil.

However, it’s worth pointing out that I have numerous patients whose health noticeably improved after taking FCLO. I’ve heard similar reports from hundreds of readers and podcast listeners, as well as from women who went through my Healthy Baby Code program. In fact, my wife would count herself among this group, and if you search around on the internet, you’ll find testimonials from many people with similar stories.

So, while I do think this report warrants more investigation, I don’t think it is cause for panic. I will continue to investigate this issue and update you when new information becomes available.

Dr. Chris Masterjohn, a nutritional scientist with expertise in fat-soluble vitamins, published his preliminary thoughts on Kaayla’s report. It’s worth reading.


Join the conversation

  1. Great link posted below, I’m resending it as everybody should know (and based on some of the comments after the link was posted, it seems that some overlooked it):

    Please take the time to read it! Their summary (provided at the end) is excellent too:

    Corganics invested heavily into the development of EVCLO, upon release of this product, the WAPF rated it below FCLO, and so sales were poor. Either in reaction to this, or as part of their marketing plan, Corganics/ EVCLO and Rosita launched a malicious campaign against Green Pastures, which included accusing them of purchasing ingredients from China, lying about their producing methods, and saying that FCLO is lower in vitamins than EVCLO. This campaign got EVCLO noticed, but the lies and rumours they were spreading were unfounded and obviously malicious, so peoples opinion of the company fell. After a warning from the WAPF about EVCLO’s behaviour, they apologies for their actions, and removed much of their campaign.

    The slander campaign seemed to end in late 2014, which is when I suspect Corganics started conferring with Dr. Kaayla, because shortly after the end of the slander campaign Dr. Kaayla voices her concern about FCLO being rancid. The WAPF sent out samples of FCLO to Midwest Labs and Leicester School of Pharmacy which shows that FCLO had no lipid peroxide species and is safe. Despite the evidence showing that FCLO is not toxic, Dr.Kaayla decides to do her own research (you need to ask yourself why), and publishes a damning report against FCLO. Dr. Kaaylas research is riddled with flaws but this seems to mean very little considering her position of trust in the WAPF (vice president). People read her conclusions and chaos ensues, resulting in the WAPF and Green Pastures being accused of fraud, lying and worse.

    As a result of the chaos Dr. Kaayla establishes her own foundation (PPPF), people are encouraged to get rid of their FCLO and take EVCLO, and according to Archie Welch sales of EVCLO are starting to increase.

    I’m quite surprised that Chris did not update his article in light of this, and would be very interested in knowing why.

    • Thank you for this helpful information.

      What do you think about the EPA/DHA ratio? Do you think GP’s product is cod or pollock?

        • I am currently considering buying the green pastures butter oil/fermented cod liver oil blend for my 3 year old in hopes of benefiting dental health. Hate there was/is so much controversy surrounding it because I don’t know which way to go. Just looking to help him any way I can.

          • Hi there, I read this article a while back as I was also wanting to purchase some for my daughter’s teeth. I went ahead with the Rosarita evclo and I also went to a local dairy and purchased some raw grassfed milk. My daughter’s teeth are doing alot better now. I initially wanted the green pastures because they blend it with the high vitamin butter oil too. But decided to wait and try the combo of the milk and evclo and its working.

            • Hi deana,
              Great news about your daughter. I am having trouble with my 3.5 year olds teeth and heading down this path for cavities due to hypo mineralisation. I can’t find a dentist on the same page. Can you recommend anyone? I am in Melbourne but willing to travel.

  2. We used the GP FCLO a few years back. We had no issues at all, and only stopped due to the cost. We LOVED the Cinnamon Tingle gel–even our kids took it willingly, and I would’ve taken more could we afford it.

    Recently got a new jar, after using the skate oil because it was cheaper. Perhaps my age, perhaps due to getting close to menopause, I have had constant edema, even though I tend to run a bit low on my body’s sodium tests our clinic runs. I read about sometimes fermented foods cause this, and so I backed off the FCLO and homemade kombucha. Swelling reduced. Coincidence–maybe.

  3. HI all, I bought a bottle of GreenPastures FCLO Sunday and took two mls mixed in yogurt Monday morning. I became violently ill within a few minutes of ingestion! I got severe stomach pain,diarrhea,and vomiting. Today is Wednesday and the first day I could keep any food down. I returned the product to our local health food store along with the story of my reaction. I would NEVER recommend this product to anyone. I have taken it in the past, perhaps, two years ago with no reaction at all.

    • You probably had food poisoning, it takes 24 hours for a ingested food to affect you. People always blame food born illnesses on the last thing they ate, but in reality it is what you ate 24 hours prior .

      • Not necessarily true. Depending on the strain and bacteria, food borne illness can strike anywhere from 3 to 6 hours after consumption and last up to a week.

  4. Your information is great and I would gladly switch because quality is very important to me. But I have two big problems with the new company. I am a super taster and I can’t handle the taste of the oil, so I NEED it in pill form in order to consume it. Also the new company does not offer a mix of the cod and butter oil. Can you suggest to them that they develop there product in pill and mixed form so that us picky tasters can use it. Oh and my 9 year old daughter is using it as well and she HATES fish. The pill is the only way I could even hope to get her to consume it.

    • Because our lives are riddled with chemicals, it is no longer enough to simply eat wholesome foods. With the normal amount of stress, chemicals, and lack of wholesome food in our environment we have to step it up a level to stay above water – so to speak.

    • 1) “Wholesome”, unprocessed foods (e.g. vegetables, fruits, etc…) no longer have the nutrient profiles they once had due the soil corrosion and mineral depletion over the decades. The expansion of factory farming has also made it difficult to obtain meats that are free of toxic residues from hormones and antibiotics.

      2) Even if you enjoy great health from a whole foods diet, taking extra supplements can always make you even healthier. And you can never be too healthy.

      3) Related to point #2, there are many examples of nutrients/herbs that the average person simply cannot get (or is very difficult to obtain) from food. For e.g., resveratrol.

  5. This isn’t a comment on the actual concerns about GP FCLO, so much as a something-to-consider if you’re one of the several people who have tried this product and had heart palpitations, brain fog, joint pain, fatigue, nausea, dizzy spells, or any of the other issues that I keep seeing this product blamed for.

    I would really like to encourage you to look into the concept of histamine intolerance if you’ve had a bad reaction to this product.

    I have two children. One can handle (and loves) FCLO, one cannot – she breaks out in eczema and has the equivalent of a mental breakdown for about 24-36 hours afterwards. If not for my older daughter, I would have assumed that the FCLO was bad, but she has never had a reaction to it and they both consistently took doses from the same bottle.

    After a lot of digging, reading, researching, and food trials, we uncovered quite by accident that my youngest has an extremely low tolerance for histamines. FCLO is a *very* high histamine food, being sourced from aged fish. If you’re having reactions to the GP FCLO, I would highly recommend trying trying a low histamine diet for a few weeks, then trying a binge of several high histamine foods that are not FCLO and seeing if you have similar symptoms. If you are, it’s probably not the FCLO, it’s probably a histamine sensitivity.

    • I totally agree with this! My daughter was taking FCLO from 6 months-present, and it took me over 6 months to finally figure out she has a histamine intolerance!! She has emotional “flooding”, and also breaks out with super red cheeks (first step) and then a huge rash on her back (really bad reaction). One big food item also contributing to it for her was Bone broth! It can be higher in histamine if it’s cooked a long time, as can many other very healthy, natural foods that many of us are eating. If you have reactions, definitely look into this.

    • Thank you! I seem to be having the same issue, stuffy nose and nausea. I think it must be histamine intolerance. So what are the alternatives to Fermented Cod Liver Oil? Just straight Cod Liver Oil I presume?

    • Is there a way to “flush” it out of your system or could you take an antihistamine like sudafed, etc. to combat the reaction symptoms? This has happened to me today and is unreal! I need this OUT of my system!!!

      • Omg, I’m not taking any of this then. By the way if you eat something like that unless you vomit (which can be a good thing) or unless you are having severe enough reaction to go to the ER (anaphalactic shock/severe breathing etc problems) you have to wait it out. And it seems the best thing is to keep sipping water, if you can handle it take an Epsom Salt bath, it seems to help stimulate the system and get the “poison” out a little. It’s HORRIBLE and I was actually considering taking this but not now. :/

  6. Bought the FCLO/HVBO Blend, tried it for 2 days, 2 capsules a day, once with breakfast, once with lunch. On the second day after lunch, I feel so nauseated that I need to go to bed right away, I’ve never had such reaction before. I stop taking the pills, I felt much better couple of days later.

  7. For me FCLO is a great product. I take the unflavoured liquid because it doesn’t taste of fish to me, just peppery cream and it tastes the same after months in the fridge. If it was rancid, surely it would taste abominable, like all rancid oils do. Ever eaten a rancid nut?
    All I know, is that within weeks of taking half a tsp per day of FCLO, my knees where no longer stiff in the mornings and when I stopped taking it the stiffness returned within weeks. Two years later and my knees are fine even if I stop taking it for a month.
    I have never had any negative reactions from FCLO but then I’m not a headachy kind of person.
    Someone above described it as a risky supplement and suggested that people should just eat other animal products instead. Unless you hunt and prepare your own food, then all the food you eat is, to some extent, processed, so what makes consuming any fermented product more risky than consuming store bought products, that are all mass prepared, packaged and stored? Also, define supplement. Butter is food, if I package it in a little capsule does it suddenly become a supplement? Is a pickle a supplement?
    Fermentation is a great way of giving food a shelf life without having to add a bunch of dodgy chemicals, so I, for one, am glad that the Green Pastures folk have revived this simple way of processing fish livers and add my voice to the testimonials of others with happy knees and other joints.

    • Thank you so much for your wonderfully unbiased analysis of the data… I hadn’t yet purchased any of Green Pastures products or any other fermented cod liver oils… and of course was concerned over the conflicting information… I have decided to try Green Pastures brand and will be sure to monitor for any negative health differences in myself since I understand the minimal risks involved.

      I hope for Dr. Daniel’s sake that she examine her motives so she doesn’t lose her following. I know I won’t be a fan… unless she issues an apology and changes her ways… I see her as a politician at this point instead of a health pioneer.

  8. Chris, I think you need to update your info to include everything. Green Pastures have done extensive 3rd party testing for trans-fats etc with nothing found, and there is a clear slander campaign against FCLO instigated by Corganics. The campaign includes (but isn’t limited to) the owner of Rosita (makers of EVCLO) making a video about FCLO, claiming it is bought from China!

    You can read about it all here:

    This kind of action is really despicable, and needs to be made as public as possible.

    • My daughter was born with eczema, a small coin shaped area on her ankle. It got worse from there. She developed the typical looking infant eczema and then it mostly cleared except for the spot on her ankle until she was 16 months old and then the backs of her thighs became covered in nummular eczema.

      I tried everything, natural anyway. I use natural products at home for cleaning and body care. I started klaire labs infant probiotics at 9 weeks old. I didnt use soap on her. I applied all the recommended oils including jojoba, tamanu, etc., raw shea butter. Badger diaper cream helped soothe the itch and redness the most but nothing cleared it. She was exclusively breasted until about 10 months old, not that it matters, she was born with it.

      At 21 months, I started giving her green pastures brand fclo, despite my hesitation from what I’d learned in nursing school about the dangers of excess vit a. Within a week, her legs were nearly clear! She is now 31 months and I find I have to give her 5 ml/day to keep her legs from breaking out. I tried the fclo/high vit butter oil combo for a couple months but the same 5 ml dosage did not manage her eczema as well as fclo alone. Despite her success with fclo, the report is concerning. With all of the mixed information about vit a, even preformed vit a, i still worry about the amount she requires and certainly the source. Please keep us updated!

      I will try the evclo noted and compare the results. It is more expensive. I hope it won’t be a waste. I am inclined to believe the traditional method of extracting the oil will prove better.

    • I purchased the Rosita brand and it is rancid – horrible fishy smell and taste! wasted my money.

  9. As an aside to all the bickering regarding FCLO, I happened upon a site “keeper of the home” wherein the author explained that one set of her Grandparents came from Newfoundland, Canada. The Grand father explained that they used to take the livers from Atlantic Cod and store them in barrels where the liver and impurities would sink and the clear oil would rise. Children would take the oil directly from the barrels into their mouths.

    This story is not unlike that told by others regarding how cod liver was stored in sealed barrels before consuming the oil.

    So argue all you want, the truth is that CLO was traditionally processed in just this manner not some steam processed, deodorized, re-vitaminized goo.

  10. Chris,

    The whole article from Dr Kaayla was very demeaning and antagonizing. If someone was to write a legit artivle, why not maintain a clear head and a clear article with no misemotion.

    That being said, I called Rosita and here’s the problem that concerns me. They process their oils in a “proprietary way” and use a family that processes the oil many thousands of miles away. They process sufficiently to not have any detectable levels of crap and they said they had to add Vitamin E to their oil (so they do process enough that they have to add a vitamin) and they will not disclose the source but said it’s also proprietary. How are they being transparent and much more important, has WAPF taken this oil and tested it? Just all smells fishy. Whats even more alarming to me was the verbal attack that Corganic/Rosita has had for a number of years. So, I would like way more transparency and I hope you demand that too.

  11. Ok, i only found out this a few minutes ago, so I hope people are still reading this topic. Sally Fallon Morrell was married to John Fallon. I did a search on John Morrell and found his obituary in 2014. Just search on forevermissed dot com for john baptist Fallon. It mentions that John was survived by his ex wife Sally Caroline Weztel. So her maiden name is same as Green Pastures David Wetzel. I wonder if that explains why she’s supporting GP at all cost. Is it a coincidence? I don’t know enough about these people to know for sure, but I always thought it’s strange that Sally would put her reputation on the line for any company.

      • If I’m following correctly, you are saying that Sally Fallon is David Wetzel’s sister? Did I get that right?

            • Sally Fallon who heavily promotes Green Pastures as being exactly the right thing to take to be healthy may have a family relationship with a key person at Green Pastures. Since she’s never mentioned it she could obviously be biased and have ulterior motives for promoting the company. In other words she’s promoting a family business but keeping quiet about the fact that it IS a family business. Which seems suspicious.
              I don’t think it’s hard to understand at all.

  12. Hi,

    I posted this following message earlier this morning on another blog discussing fermented cod liver oil:

    I write to you as I recover from some incredibly uncomfortable food poisoning symptoms after taking green pastures fermented cod liver oil.
    After taking 2 servings on day one (of 2ml) when I tried to sleep that night I woke up at around 2am with really bad acid re-flux. I quickly googled a cure and found that some people have tried apple cider vinegar (luckily I had some) so I sipped some of that and after 10 mins (feeling absolutely awful and very close to vomiting) I was able to get back to bed. The next day I woke not feeling too bad so I decided that I’d probably just overdone it and instead, early in the day this time, took a single 1.5ml dosage with some food. I didn’t feel anything up until bedtime.
    That night was pretty much sleepless as I developed sharp pains in the stomach and cold sweats. I got out of bed early the next day telling myself I’m done with the FCLO (angry because I paid $80 AUD for it after an emphatic recommendation by the staff at a local health store)
    I felt incredibly drained and told myself ‘you just need to get some food in’ well as soon as I took my first bites of the eggs I had made for myself i had instant gurglings and pain in the stomach and ran to the toilet with diarrhea. So the rest of the day was spent either on the can or lying in bed. In the evening I had a similar experience to previous nights but this time with constant stops to the toilet.
    It is now 5:34am, the same morning, I haven’t had a wink of sleep and i’ve just emailed work saying I will be sick and unable to work tomorrow (of which i get paid pro rata so now a payless day!)
    I don’t know what can be done, but i’m tired and angry about it!


    • Do people with posts like this really think that this means the product is bad, or to be blamed? So many people take the product without adverse reactions, it seems that those who experience unpleasant side effects are forgetting that their own body’s chemistry plays a part. For one thing, it could be an allergy or sensitivity to some part of the supplement. Another possibility is that your body needs to adjust to the new supplement, thus you need a smaller dose for a while until your body adjusts. This goes for any supplement, any of this could apply. You can’t just outright blame the product for the way your body reacts to it, without considering the possibility that it’s your body, not the product. Different people react differently to everything in our world. If you have an adverse reaction, it’s likely that someone else could take the same dosage from the same bottle of product and be just fine with it.

  13. What are your views on nutra pro virgin cod liver oil vs Rosita EVCLO? The former appears to be a lot cheaper while being the same. They say the oil is centrifuged but otherwise not put through any heating process..

  14. Chris,
    How do they ferment a fatty acid? I thought fermentation could only take place with carbohydrates….

    • Traditional Inuit staples included fermented fish, and I believe that traditional Chinese cuisine boasts of fermented eggs. So apparently, no, sugar is not essential for fermentation.

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