I’ve written in depth before about the supplements I personally take, which for a long time included fermented cod liver oil.
If you follow many bloggers in the natural health community, you’ve probably seen the recent drama about the potential quality issues with fermented cod liver oil. I delve into this in depth below but the summary of my personal current opinion on the issue is that:
- There is conflicting evidence on the safety of fermented cod liver oil (and more recently even on the safety of any omega-3 supplements) that warrant more research.
- Health and nutrition continue to become more and more personalized so what works for me is not likely to work for you and vice versa.
- I personally am focusing on getting all nutrients from food whenever possible and with rare exception and am sticking to foods like sardines and other low-mercury fish in place of supplements.
It is important to note that this is strictly my personal opinion and is in no way close to medical advice (nor is any information on this website). As always, I encourage you to do your own research and due diligence on any health related decisions.
Fermented Cod Liver Oil is considered a traditional food that has been recommended by the Weston A. Price Foundation and many real food bloggers (including me) for years. It was even the WAPF recommended brand for use in homemade infant formula and many members take it religiously.
On August 21, 2015, Weston A. Price Foundation Vice President Dr. Kaayla Daniel released a 100+ page report detailing the results of independent lab tests that she had on samples of Green Pastures Fermented Cod Liver Oil and that alleged major issues with the brand, including rancidity, lower levels of nutrients than were claimed, and sourcing issues.
Dr. Daniel’s report claims that FCLO is not actually fermented, is rancid, putrid, and adulterated with other (cheaper) oils. It also alleges that there are lower levels of fat soluble nutrients in FCLO than claimed and that the oil isn’t even from cod. Serious claims from a well-respected person in the real food community.
Understandably, this has left many people in the real food community reeling and looking for answers. I’ve gotten many emails, comments, and social media messages in the last few days asking what my take on the subject is, and have spent a lot of time researching this myself.
Below is my personal opinion and research on this issue based on the information available right now. I will continue to update this post as more information is revealed.
My hope is that no matter the outcome of further research and study about fermented cod liver oil, the real food community will take this as a lesson in the importance of verifying the quality of supplements and use this as an opportunity to improve the real food movement, rather than to divide the community.
Is Fermented Cod Liver Oil Safe or Rancid?
In short… I don’t know.
Based on the information available from both sides, I don’t think it is possible for anyone (short of Green Pastures, the company producing the fermented cod liver oil in question) to know the answers to all of the questions that many people are asking right now. At the same time, there are some holes in the report from Dr. Daniels and some potential financial ties that have come to light that call her motivation into question.
When our family first started taking fermented cod liver oil years ago, I did a lot of research on the company and on cod liver oil in general (as anyone should do before taking fat soluble vitamins regularly). The only lab reports I was able to find at the time were from Green Pastures and they showed no rancidity in the fermented cod liver oil and verified that FCLO did contain the fat soluble vitamins it was known for.
The recent report from Dr. Daniel calls these tests into question. Her results have the lab company and the party funding the test blurred out, which is somewhat suspect, though I do not think that this necessarily discredits the information in the reports. The report does, however, make some assertions about certain compounds being harmful as a justification for why FCLO is not safe, and some of these claims are not backed by existing science (or are at least controversial).
In the last six months or so, I’ve actually been researching and testing different forms of cod liver oil after readers have inquired about different brands and reported issues they’ve had with FCLO.
Our family has seen benefits from taking fermented cod liver oil over the years, including reversal of tooth decay. I’ve also noticed that my skin is naturally more sun tolerant since taking FCLO, probably from the fat soluble vitamins it contains.
At the same time, there is the possibility that the quality of Green Pastures FCLO has changed since I researched it years ago, or that more recent lab testing has been able to reveal problems that were undetectable years ago.
Fermented Cod Liver Oil: The Claims
FCLO is Not Fermented:
There may be some truth to this claim. I’ve talked before about the importance of fermented foods for health, and why the naturally created beneficial bacteria in fermented foods are so important.
The red flag that Daniels explains is that oil cannot ferment. The process of fermentation requires the presence of a carbohydrate as the food for the fermentation process. Many people (including me) assumed that an unnamed carbohydrate was used for the fermentation process but was removed by the process so it was not listed on the ingredients or that the livers themselves were fermented and not the oil (as an oil can’t ferment without another ingredient).
Green Pastures owner Dave Wetzel has been less than transparent about this fermentation process, though supposedly he has brought several WAPF members and high profile bloggers to his facility to see the process and verify its quality. (I have never been to the facility and have no firsthand knowledge of this process, so I have to rely on Dave’s explanation of his process).
This is one area that I hope we see more detail on from Green Pastures and from independent sources in the future. For now, the debate about the process used and what part of the process actually requires fermentation does not necessarily mean that the final product is not high quality, but it does raise some interesting questions to explore.
FCLO is Rancid:
Fats and oils cannot ferment without carbohydrates, so what happens when they are exposed to the conditions of fermentation? In short, they go rancid.
This is the basis for the claims in the new report. The independent lab results from Dr. Daniel show several biomarkers of rancidity in the samples tested (these were not present in the reports I found in my initial research).
In Daniel’s tests, peroxide, free fatty acids and other biomarkers of rancidity were found. I was unable to find clear answers directly from Green Pastures, though I found several older articles and interviews in which Dave states that his product does not contain these biomarkers or that the substances are not harmful. Again, more research is needed from independent sources on this.
Low Levels of Vitamins:
Another claim in the reports is that FCLO contains less fat soluble vitamins than claimed and that the Vitamin D is in the form of D2 and not D3.
The common consensus among medical experts is that D3 is the preferred form, though Green Pastures claims that D2 is equally safe and effective. To be fair, all forms of cod liver oil contain higher levels of D2 and this does not necessarily raise a red flag, but again, more research is needed.
Also, Green Pastures has never made claims, to my knowledge, about the levels of nutrients in their products, carefully explaining that they are a food product and that levels can change.
Not Actually Cod:
The report further claimed that the DNA tests on Green Pastures products showed that the livers used were from Alaskan Polluck, not cod. This seems to be partially an issue of understanding of fish species and families, since:
The Alaska pollock or walleye pollock (Gadus chalcogrammus, formerly Theragra chalcogramma) is a marine fish species of the cod family Gadidae. Alaska pollock is a semipelagic schooling fish widely distributed in the North Pacific with largest concentrations found in the eastern Bering Sea.
After hours of research, I could not find any definitive answer directly from Green Pastures about the origin or species of the fish they use. The closest I could find was Dave’s vague answer from his own FAQs:
Ok, The question arises on the topic of location of the fish. The fish school in the northern, cold waters around the Arctic Ocean. They do not have a nationality and a fish can school for a 1000+ miles in its life. So the relevance of the specific spot the fish is cleaned is not relevant to the discussion, ‘is the fish safe to consume’.
Red Flags from the Report
While Kaayla’s report certainly raises some concerns about FCLO, it also raises some concerns about its own validity. For instance:
- The labs used for the testing and who paid for the independent testing is not disclosed. This isn’t necessarily a red flag on its own, but given the rumored history of drama within the WAPF organization, I think it deserves further investigation. Given how much heated press this report has generated, I can certainly understand the potential desire of a donor to remain anonymous in the report, but it does raise a red flag.
- Though I have no firsthand experience with any of the board members of WAPF, including Sally Fallon or Dr. Daniel, reports of internal drama run rampant in the real food community. In fact, I avoided joining the WAPF for years partially because of these claims. We have not heard an official response from WAPF or Green Pastures yet, and I think that thoroughly evaluating both sides will be an important step for any of us looking to understand the long term validity of these claims.
- The one funding source that Kaayla mentions in the report, Dr. Ron Schmid ND, has a long and somewhat dramatic history with FCLO. He reportedly took (really large doses- above the recommended amount) of regular cod liver oil and then fermented cod liver oil for decades and attributes them to his severe heart disease. He has also stated publicly that he attributes his miraculous recovery from heart disease with discontinuing taking FCLO. Not exactly an unbiased source. Again, this does not discredit the information, but does raise some additional questions.
- While Daniels lists sources for many of her claims, she doesn’t list her sources for many of her quotes. In fact, while she says she talked to many experts (including “top university professors, scientists, researchers, lab managers, doctors and other health care practitioners”), these sources are unnamed for many of her more serious allegations. Obviously, these claims would carry much more weight if they were substantiated and sourced.
- It also raised a red flag for me that Daniel has a call to action for her own services in the report, saying: “Finally, if you think you have health challenges related to FCLO consumption, share your story with friends, colleagues . . . and me. If you think you’ve been harmed, I would like to offer you a FREE mini appointment by phone or face-to- face on Skype. To share your story or to make your appointment, contact me at ***********@earthlink.net.” I can understand her desire to help others if she truly feels that FCLO is harmful, but a report making these allegations does not seem like the appropriate place to make this offer. Again, not a reason to discredit the report, but a red flag.
- Emerging information has also revealed some potential political ties from the new organization Dr. Daniels founded after leaving/being forced out of WAPF and the makers of the Extra Virgin Cod Liver Oil product she recommends. In other words, the company she recommends as an alternative to FCLO is a sponsor of her new organization so she may have a bias here. Additionally, there is a lot of information floating around about potential conflict within the old organization hierarchy of WAPF that suggests there may be much more to the story on both sides.
The Bottom Line
Based on the available information at this time, it is extremely difficult or impossible to draw a definitive conclusion on the issue of the quality of Green Pastures FCLO or other CLO products. I think that this whole “scandal” is a symptom of a much bigger problem- the mud slinging between competing companies and emerging attacks on both sides of the fence.
The report brings up some serious points and hints at some possible misleading information from Green Pastures over the years. As a mom who has given FCLO to my own family for years and seen good enough results to share my experience with you, I am extremely angry and disappointed in Green Pastures if any of these claims turn out to be true. At the same time, there are some serious holes in the Dr. Daniel’s report and the potential financial ties to the new company bring up more questions.
I think more research and disclosure is needed from both parties, and like I said, I hope that all of us in the real food community will use this as an opportunity to improve, learn more, and get to the truth, and not as an excuse to argue and divide.
At the end of the day, I have to hope and trust until I see evidence to the contrary that both the founders of Green Pastures and Dr. Daniel are interested in health and serving their communities and continue to evaluate any information as objectively as possible.
At the same time, I don’t think either side is unbiased.
Green Pastures, of course, derives a profit from the sale of their FCLO. Dr Daniel has a rumored history of contention with different parties within WAPF and with Green Pastures as well as potential financial ties to the new EVCLO company. Again, none of these are relevant to the validity of the data in the reports or even necessarily to the motivation of either party, but they do provide a possible motivation for slanting information one way or the other.
At the end of the day, things are rarely what they seem on the surface and my guess is that we will continue to find more from both sides of this story.
What Our Family is Doing
As I mentioned, after many reader questions, I have been researching FCLO and alternative cod liver oil sources for months.
For now, my family is not taking any of these products and I am not linking to or sharing about these products.
Since there is so much conflicting information on the issue right now, please share any information or research you’ve found in the comments below. Has your opinion of FCLO changed as a result of this report?
Discussion (315 Comments)
I remember Green Pastures being the usually recommended FCLO manufacturer. There are no other fermented fish oils?
Does the report mention where the batches were procured from? Has anyone tried to reproduce the study?
I am not sure where I stand on this either. I really don’t like the idea of taking non-fermented fish oil as it seems like it would go rancid far too quickly.
Thanks for another great article
Green pastures is the only available FERMENTED cod liver oil. All other brands are fresh and un-fermented. The problems that the study points out is that the “fermentation” process is really just rancidity, because you can’t ferment fats. So would you rather take cod liver oil that may go rancid after a while, or “fermented” cod liver oil that’s already rancid?
When I first heard of the FCLO, I was skeptical. I was like “how do you ferment oil?” but people were so rabidly in support of it, I thought I’d give it a try. I bought a bottle of the liquid and took 2ml daily until the bottle was gone. I never saw any benefits, but I did burp up awful cinnamon and rotting fish taste for hours after taking it. I never bought any more.
They do not ferment the oil, they ferments the liver in saltwater (+ a culture as a starter), and they extract the oils that flows out of the fermented liver and to the top of the salt water.
What Christer says seems to make sense. People have fermented meat for a while so I presume
fermenting cod liver oil is certainly doable. I still don’t know what to make of the report and don’t know how green pastures handles it’s particular fermentation process.
If I don’t continue with FCLO (which I probably won’t at least until I hear more). I will probably just eat fish. Fish oil from what I can tell goes rancid rather quickly and I don’t feel safe keeping a bottle around for months after it presumably has already been shipped/stored in a store for months. I liked FCLO as it presumably protected the oil from such problems.
you can not ferment oils, and that makes the whole questioning about if the oil is fermented or not stupid. The oil should not contain any lactic bacteria. The whole attack from Dr.Daniels is with out any logic. Either is she paid to break down the respect of WAPF and GP, or she has an own agenda. I am totally confident with the products, and I know they are not rancid. I also know that big forces want WAPF and GP and their likes dead because they are industry killers (making people look at real foods). The whole Dr. Daniel stinks !
This is what I thought. Who would want to ferment oil? Of course it’s the liver that got fermented.
I’m from Newfoundland, which was THE place for the cod fishery from several hundred years. Overfishing has mainly wiped out the stocks, in particular since the 1970’s, when the use of radar and very efficient “harvesting” tech started to be used.
But I remember my grandmother, who was born in 1921 and has now passed, telling me about cod liver oil. Most everyone in the family worked in the small-scale inshore fishery. Using small boats, nets and hand-lines, they made their catch, and it was sustainable. She described the process of harvesting the livers.
The cod were cleaned (gutted), split, washed and then brined before laying out in the sun to dry. This was their only way to preserve anything back then, there was no electricity and no refrigeration.
When each fish was gutted, the liver was taken out and tossed into a wooden barrel. I should’ve asked her if they washed them first in salt water. I’m not sure. The barrel would eventually be filled with livers, and these would be melted down to extract the oil, when they had accumulated enough.
Did they rot? Apparently not. Maybe they weren’t in the barrel long enough. I wish I knew more about the process they used. She is gone now and can’t tell me. The melting down would be over a wood fire heater, and probably would just be high enough to melt out the oil.
She said she would go to the fishing stage (like a shed, on a wharf by the water), and dip up a cup of cod oil and sip it. She loved it. She went on to have 12 children, over a 30 year time frame! I have an uncle and an aunt not much older than myself, as my father was in the middle!
ANYWAY, I don’t think they “fermented” it so much, consciously. But the livers were in the barrel for some time before it was melted down, and didn’t spoil. It was also cold there, even in summer, it wouldn’t get very hot. Especially by the sea.
I asked her if it tasted “strong” like the cod available for sale does. She said no, it was very light and not at all fishy or strong-tasting. If she could drink it on occasion by the cupful, it surely didn’t taste like the commercial products being sold, including the “fermented” brands–which I can’t speak to, I have not tried them.
I went to a GP lecture many years ago, and they are located in Nebraska. Seeing pictures of the vats, this made me uncomfortable as the climate in Nebraska is a far cry from a Northern country where these types of traditional liver oil practices would take place. I asked about it and was told it was fine, but it still made me uncomfortable… to just ignore the fact that the original method came from a completely different climate. It can get hot in Nebraska. Not sure if it matters or not (or even if the situation is still the same) just my own observation.
What a beautiful share Carmel. What a gift that your grandmother had this experience and had the opportunity of sharing it with you.
I just received my 1st two bottles of FCLO from Green Pastures. Split a bottle between my 80 yr old mother and 90 yr old mother in law. I’m wondering if I should get it back and dump it. ;[email protected]
I was about to buy this to replace my current supplement, but for now, I’ll hold off. I’ve been taking Nutricology D3 Complete and will continue to for now. https://www.amazon.com/Nutricology-Vitamin-Complete-Capsules-Count/dp/B003YQCZDC
Thanks for this. The whole thing has been stressing me out and as the mom of a little one and starting a business I haven’t had the time to do all the research. My LO coughs and cries from the burn of FCLO every time so I don’t give it to her. I am going to try EVCLO next and see. When this was all first going down I was really bummed at how it was being handled by some of the WAPF folks. My chapter leader sent out an email to our local people raising her concerns around FCLO and she got a direct call from Sally who scolded and attacked her on the phone. It was really disappointing. Why so much drama? Can’t we just come at it from a place of curiosity and understanding? Thanks for being so calm and wise about the whole thing. And for doing the research.
I’m pretty sure there is some affiliation between Green Pasture as a company and the WAPF, which I think is an important point for the discussion.
There has never been, and is not now any affiliation. This point has already been discussed in length on various blogs. Green Pasture simply makes a great FCLO product, and tries to follow the traditions revealed by Dr. Weston A. Price.
I thought i read somewhere that GP contributes money the the WAPF
They help sponsor their annual conference but so do lots of other companies and that’s all fully disclosed.
The traditions revealed by Weston Price make no mention of FCLO. Only of seafood consumption. Dr. Price used non-fermented CLO in his patients.
I so much appreciate your thoughtful and unbiased review of the FCLO controversy. My grandson and I have been taking it in recommended doses; however, we have stopped for now until more definitive research and testing emerge. I’m anticipating info from Chris Kresser as well.
Thanks again for all you do within the healthy living community!
Katie, once again you have proved why you are one of my favorite bloggers. Thanks for wading through all the details of the reports and the accusations on both sides to give your readers an accurate, fair picture of what is happening with the FCLO issue.
Katie, thanks so much for dealing with this issue so quickly. Obviously a lot of us are stressed about it. Would you continue using the FCLO in your diaper cream recipe?
Yes, I have no concerns with topical use and nothing in the report was definitive or made me doubt the safety of cod liver oil, just potentially its effectiveness
The question of whether the oil is rancid is in itself a question of whether it is safe to consume. Rancid oils/foods are unsafe to consume, and according to some scientists, they are actually dangerous to consume.
Thank you for sharing your research on Green Pastures FCLO. I’m going to try your new recommendation.
I’m interested in knowing what size serving of the Rosita Extra-Virgin CLO you would give to an 8 year old. Do you have a suggestion based on your experience with your own children?
Hi. Does this apply to all cod liver oil or just the liquid type and the brand you mentioned? We currently take it in gel cap form and a different brand. Thanks so much.
As far as I know, Green Pastures is the only brand of FERMENTED cod liver oil available. It is the one the article by Dr. Daniels was written about and the one that has come into question as to the quality and validity of it’s claims. Other brands of cod liver oil are fresh, un-fermented cod liver oil and do not have the same potential issues of rancidity and putrefaction as the fermented cod liver oil. All other brands of cod liver oil (NOT fermented) should be perfectly fine to take as a vitamin supplement.
Thanks. That’s what I thought. Just wanted to be sure. 🙂
All other brands? No. There are many other issues of concern in the way cod liver oil is processed than the ones mentioned here that are to do, specifically, with fermented oil. Do your research on any oil and brand you take.
I took fermented cod liver oil from Green Pastures for a short time but discontinued use because it gave me extreme diarrhea each time i used it. I quit and have taken a couple of other none fermented brands without any of those problems.
The “study” you posted a link to isnt at all what an actual factual study looks like. It appears to be more of an opinionated based article and not even close to an actual study that was performed properly….I went to school to learn how to decipher real studies from false studies from sketchy studies and this was is definitky sketchy. I’ll continue taking FCLO with zero hesitation.
Yes, me and my family will continue to take it as well. I went to green pastures website and I personally feel they have been very upfront about everything and have explained, in depth, the process they use. I don’t honestly see the freak out here. I truth their company and their products.
Jackie- Do you have a link to a scholarly article on the benefits of FCLO? I couldn’t find one.
Katie, I have a question, you said you are testing a virgin cod liver oil, is it Rosita brand? I had impression that it was reading your other post.
Katie - Wellness Mama
It is. And I still am researching and have mixed feelings. Some research is now indicating that any omega-3s that aren’t from a fresh fish source can be harmful.
By fresh fish do you mean only raw? As in never frozen or cooked?
I think she means fresh food ,not supplement form.
You may wish to look at Ray Peat’s view on this http://raypeat.com/articles/articles/fishoil.shtml. he called out that fish oil and all PUFAs go rancid very quickly. It is a minefield. Long term studies do not appear to have been conducted on fish oil, even if they work at reducing inflammation it is said this is due to the omega 3’s initially balancing the omega 6 which we have a much higher imbalanced intake of, but what happen long term.
Do you take any FCLO or CLO now ,when there are a lot out there?Or you still don’t.
Interesting. I have read your previous posts, but always felt a caution about the FCLO. Consequently, I instead purchased Nordic Naturals CLO, simply because it is a brand I trust. I will be interested to see how this all plays out….
interesting article about Nordic Naturals though – backed by scientific evidence from the looks of things.
Love the honesty and forthright nature of this article !
It is a touchy and confusing subject…. I stopped taking FCLO because the vitamin A was giving me headaches….
I hope (& believe there will be) a regulatory committee (not bought out like FDA) which stringently researches and ‘qualifies’ vitamins and supplements.
Love your articles Wellness Mama! xo
Skate liver oil contains more D-vitamin and less A-vitamin then FCLO, and is recommended to people eating foods rich in A-vitamins, such as raw liver.
Taking zinc will cure the headache caused by too much Vitamin A. The bodies zinc stores are depleted by metabolizing the Vitamin A. That’s why I am personally very careful with consuming too much Vitamin a rich foods. Especially since nowadays we are surrounded by a zinc depleting environment (e.g. Xenoestrogens, metabolic disorders caused by medication leading to high needs of zinc).