When several of my readers were concerned because of Dr. Kaayla Daniel’s report, “Hook, Line and Stinker! The Truth About Fermented Cod Liver Oil,” I started researching into it. The report states that the popular Green Pastures’ fermented cod liver oil is not really fermented, is in fact rancid and putrid (chemically), is adulterated with vegetable oils, and does not contain the reported vitamins and minerals. It goes on to say that the original Dr. Weston A. Price wouldn’t have recommended it at all.
I dismissed this as a bit ridiculous…at first. Surely if the product were not only not beneficial, but actively harmful, we’d know by now, right? People wouldn’t be experiencing health benefits from the product and the truth would have gotten exposed long ago.
But, I owe it to my readers (and my family!) to look into the issue more, and that’s what I did.
You should know that I have no financial relationship with either Green Pastures (GP) nor competing companies. I have been purchasing and taking GP products for several years. I also do not belong to either of the foundations I’ll mention, and never have. I also do not know or have a professional relationship with Dr. Daniel or anyone else that I will name.
Let’s dive in.
Can Cod Liver Oil Be Fermented?
Let’s start with this key question: what is fermented cod liver oil? Can cod liver oil even be fermented?
It’s been driven into us that we need more fermented foods. That fermented foods are to be prized, because of their positive impact on our gut health. And that’s true — real fermented products generally are beneficial to us.
However, the reason they’re beneficial is not just because they are fermented, but because they contain specific strains of beneficial bacteria. It’s these strains that we need (that’s information for another post). Not all fermented foods are good, either — think about a bottle of juice left in your car on a hot day! That is fermented, but there certainly aren’t beneficial strains in it, and I wouldn’t recommend drinking it.
However, in order for fermentation to occur, and especially to produce the beneficial strains of bacteria, it requires carbohydrates. That is, sugar or starch in some form. We can and do ferment fruits, vegetables, and grains. Done properly, with a true anaerobic system, it will produce high concentrations of beneficial microbes (again, information for another post).
We can’t ferment oil, though.
Fat simply doesn’t ferment. It, instead, becomes rancid. It oxidizes. This damages the vitamins and minerals in the oil, and makes it potentially harmful to our bodies.
That’s exactly what Dr. Daniel is claiming has happened in the case of Green Pasture’s products. But Green Pastures says that their products are traditionally-made and beneficial.
Which is correct?
How Was Cod Liver Oil Traditionally Made?
Both are sort of true.
From reading a well-cited history of cod liver oil production from the Price-Pottenger Nutritional Foundation (not associated with the Weston A. Price Foundation, nor any particular cod liver oil company), I’ve learned that the debate over production methods dates back to the early 1800s.
Three main methods for producing cod liver oil are described throughout the literature.
Method one: Bringing the freshly-caught fish to the shore on the same day, cutting out the liver and protecting it from oxygen and allowing the oil to naturally release, possibly with cold pressing. This produces a very light-colored and flavored oil, and is called extra-virgin cod liver oil.
Method two: Either because sea voyages were long, or after the EVCLO was extracted, cod livers were allowed to sit in a vat for weeks at a time, essentially rotting. As they broke down, the oil naturally rose to the top and was poured/scooped off. This produced a dark brown cod liver oil. (This is Green Pastures’ process.)
Method three: Heat or chemical extract, including steaming or boiling the livers, or using solvents like hexane. Steaming or boiling produced pale to light brown oil, while solvents produced dark brown oil, which then underwent deodorizing and other processing.
Chemical solvents definitely aren’t traditional and have only been used for the last 50 – 60 years. Prior to that, it was cold-pressing, “fermenting,” or steaming/boiling.
In the 1800s, they argued over which cod liver oil was really best. Some found that the brown version contained more vitamins than the lighter versions. However, the brown versions were usually used industrially, or topically — not internally.
In the 1900s, some experiments showed that the vitamins in the brown oil were damaged, and that if it was exposed to the sun, it could even cause problems in some people. Plus, this brown oil is known to be acidic, strongly-flavored, and difficult for some people to take.
What we have to know now is, is this brown oil really that bad…or could it still be good for us?
Biomarkers of Rancidity
Have you ever tasted rancid oil?
The other week I asked for some oil for salad when I was out somewhere. I knew that the oil wasn’t used frequently and was about a year old. It had a distinctive rancid taste/smell to it. Liquid oils do go rancid anywhere from a few months to several months after purchase. Oils stored in clear bottles that are exposed to heat and light might be rancid when you buy them (like vegetable oils — it’s just one reason to skip them). Even quality oils stored in dark glass, away from heat and light, will eventually go rancid. That was the case this particular time (olive oil stored in a dark glass bottle; it was just too old).
Many people say that fermented cod liver oil doesn’t taste or smell rancid. In fact, that was my first reaction when I heard about this report — I’d know!
However, it’s a little more complicated than that.
There are several actual biomarkers of rancidity. It’s not just a smell/taste thing, it’s something that you can test. That’s what Dr. Daniel’s report does. She sent unopened bottles of FCLO to several different labs to test these specific biomarkers to get a clearer picture of whether or not the oil was rancid.
One of the early markers of rancidity is peroxide. This is what tips us off to rancidity when we smell and taste a rancid oil. Peroxide values start out very low, then increase sharply as an oil becomes rancid, and then drop back down because the peroxide is broken down further. FCLO is at the late stages, so peroxide values are low. This, and other markers, have been used to prove that the oil isn’t rancid.
However! The free fatty acids are extremely high in fermented cod liver oil. That is a clear marker of rancidity. GP claims that it is not, and that there are benefits to free fatty acids. However, this study shows that free fatty acids in the body contribute to insulin resistance and the development of diabetes. This study links them to obesity, heart disease, stroke, and more. There are dozens more studies that I ran across attributing FFAs to cause insulin resistance and obesity. There is clearly no health “benefit” to these!
On the issue of oxidation and virgin cod liver oil, Dave of Green Pastures has this to say (from the FAQs):
“Virgin fish oils or ‘extra low oxidize oils’.??The production of ‘extra low oxidized oils’ differs from traditional production methods for fish oils and fish meals. Extra low oxidized oils’ are produced from materials from food operations. This can for example be material’s from food operations. This can for example be material after filleting of high quality (i.e. very fresh) salmon and herring. The raw material is processed very shortly after catching. The process involves heating to below 100Degrees C for example to a temperature around 90*95 degrees C for the time needed for the material to pass through an indirectly heated tubular scraped surface heat exchanger. The heated suspension is then separated in a suitable decanter in order to isolate the oil. The semi solid protein phase that is obtained from the same process can be valuable starting material, for example for production of marine protein hydrolysates. Because of the gentle processing conditions and selections of raw materials these oils are generally suitable for direct use as ingredients foods and beverages.??An example in Norwegian virgin cod liver oil production. The preparation for this product, including winterization, distillation, blending drumming and bottling is conducted in a manner that ensures the product is carefully processed to concentrate the healthy long chain omega-3 EPA and DHA fatty acids while removing the unwanted environmental chemicals ………………
I’m big on Bio-feed back testing and energetic testing. You know what is real and not real for each individual and product. I prefer this over defining a product on a label or fancy advertising. One can manipulate words and defining terms to meet a goal. But Bio-feed back testing and energetic testing can’t be fooled by words.”
This is not really an answer; Dave is merely summarizing the process used to produce virgin cod liver oils (with random punctuation to show how ridiculous he finds it), then suggests that if you think it’s good, it is good, and that scientific testing isn’t actually important.
What’s This Oil Made Of?
We’re not done yet.
As I have been looking into this issue, I have researched several different cod liver oil companies from all over the world. Some currently only sell in Iceland. What I have noticed is that they all deliver very clear details about the fish they use and how they process it. The fish used in most cod liver oils is the Gadus Morhua, a specific type of cod that is high in the desirable EPA and DHA fatty acids.
However, when asked where GP’s fish comes from, Dave says this (again, from the 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’.
That is…bizarre, frankly.
There’s no mention of exactly what type of fish is used or where it actually comes from. The issue is actually skirted. (Dr. Daniel’s report, and comments from several others I talked to, note that Dave often skirts questions about fish type, location, fermentation process, etc.)
The DNA tests in Dr. Daniel’s report show that the fish in fermented cod liver oil can’t be the Gadus Morhua cod. Rather, it is likely to be pollock (closely related to cod) or dogfish (much cheaper and often substituted for cod). But, we don’t actually know at this point. The lab reports aren’t conclusive and Dave isn’t saying.
There’s more to the report than I’ve shared here — it’s more than 60 pages. Feel free to read it for yourself.
How Did This Happen?
If you’ve been taking fermented cod liver oil, you probably feel about like I do — upset, frustrated, disbelieving. This is a product I actively recommended for years, and have taken myself and given to my family. It’s basically considered the “Gold Standard” in health supplements in the real food world.
I’m going to make this part brief, because it’s not the truly important information, but it bears mentioning.
The work of Dr. Weston A. Price has proven extremely valuable to a number of people. I stand by the dietary recommendations based upon his work. In fact, there’s the Price-Pottenger Nutritional Foundation dedicated to spreading these principles. PPNF dates back to the early 1950s and is a non-profit organization that shares this information but, as far as I saw, has no financial relationship with companies that make specific products (that is definitely true for cod liver oil; I haven’t looked further).
In the late 1990s, one of the board members, Sally Fallon Morell, had a disagreement with the PPNF board over an issue, and left the foundation. She then started the Weston A. Price Foundation in 1999. WAPF is similarly dedicated to the principles of Dr. Price’s nutritional studies and advice. Neither foundation actually was started by or endorsed directly by Dr. Price; they are just based on his research.
This is where it gets dicey. According to reports from former chapter leaders in WAPF, leaders in WAPF have significant paid relationships with a number of companies, including GP. This isn’t necessarily problematic; as a business owner, I seek out financial partnerships with companies whose mission and products I believe in and want to endorse. I assume WAPF is doing the same.
However, many of the details of WAPF’s positions on various issues are not in line with Dr. Price’s research at all. Dave states on GP’s site that a good dose of cod liver oil is up to 3 tablespoons per day, and that there are sources claiming 6 – 8 oz. per day is beneficial. PPNF quotes Dr. Price’s actual work, where he states that doses should not exceed 1.5 tsp. per day. That “3 tablespoons” suggestion exceeds Dr. Price’s recommended dose by a factor of 6.
WAPF also has unusual and controversial positions on several other issues, including breastfeeding, and has given out poor breastfeeding advice.
According to my contact who is a former chapter leader, Morell and others in the organization lead with an iron fist, essentially kicking out people who do not agree with her positions. Those who have called out Morell and others for recommendations that clearly go against science have been ridiculed and ignored. The organization is extremely powerful, a central part of the real food/traditional foods movement, and has serious political issues. Their positions are partially informed by Dr. Price’s work, and partially by Morell’s personal experiences and beliefs.
That is what occurred here. WAPF/Morell and GP have an ongoing partnership. WAPF has made sure that GP is seen as the top brand — so much so that all other cod liver oil companies have to field questions about how theirs compares to GP and why it isn’t fermented (from my experiences reading their FAQs plus their social media pages). There’s no evidence that it’s specifically beneficial or that their process is safe or healthy, but Morell and GP stand firmly behind it anyway — this stubborn stance is typical of their actions on many key issues.
It’s notable that Dr. Kaayla Daniel, who issued this report, is (or was, possibly until right after this came out), the Vice President at WAPF, and that she issued the report despite being told by the other foundation members not to do so.
I’ve seen some of this occurring and have slowly distanced myself from WAPF itself over the last few years, although as I said, I continue to recommend the dietary principles from Dr. Price’s work. This foundation is not representative of him or his work.
What About Cod Liver Oil Now?
The thing is, we can’t throw the baby out with the bathwater. In fact, cod liver oil absolutely is beneficial. There is a large body of evidence, both recent and historical, showing this.
There is first, Dr. Price’s work. He shows a small dose, 1 – 1.5 tsp. per day of equal parts cod liver oil and butter oil, are very beneficial to health. He does caution against overdoses (the vitamin levels required from these natural foods is far less than WAPF claims).
There is also quite a lot of recent research. This study shows that cod liver oil is anti-inflammatory. This one shows it helps prevent upper respiratory infections. Basically, it contains good levels of vitamins A and D, omega-3 fatty acids, and co-factors not yet discovered that make it more effective and beneficial than vitamin D supplements alone (which some health professionals now think may be dangerous, at least in excess).
You can read a lot more on my blog: Everything You Need To Know About Cod Liver Oil
I still recommend cod liver oil.
I needed to figure it out because I wanted one for my family to use. I looked through many brands and processes. I looked for one that I felt was safest and best for my family, and now I offer it through my store (Earthley Wellness) for you too! It is made from Alaskan Cod and left virgin. You can get it here: Earthley’s Cod Liver Oil
My original feeling, when I began looking into this issue, was that there was some missing information and fermented cod liver oil was really just fine. After all, I just bought more and I have plenty of it sitting in my fridge and cabinet now. I’ve been taking it daily and have even shared that.
After I read for a while, I thought, “We’ll probably finish up what we have, then look into something else.”
When I finished reading everything, I thought, “We have to stop this now, and get on some true anti-inflammatories to get rid of the effects of this stuff.” I have a whole bunch of things I now suspect may have been related to fermented cod liver oil use, but I’m not going to talk about those today. This is about the controversy, not my personal situation.
That’s the bottom line. Cod liver oil (or whole cod livers) can’t be fermented, it is rancid, rancid foods are high in free fatty acids that are linked to cancer and diabetes. There is nothing beneficial about this “special process.” Virgin cod liver oils, however, are beneficial and that’s what I recommend.