The confusion over the Green Pastures’ fermented cod liver oil continues.
Many people feel very uncertain what to believe right now — or who. They aren’t sure which test results to trust, or why. Right now, there’s a lot of he-said-she-said going on, and a lot of wild speculation about who is being paid what to say which.
In my opinion, all parties involved mean well. Nobody is being paid to promote a specific agenda; everyone truly believes in what they are sharing. It’s not really worth our time, anyway, to smear any individuals involved in this situation.
We still need to know the truth, though. What is historical cod liver oil production? What did Dr. Price recommend? And what has modern science taught us about the different production methods — and which is the best now?
First we’re going to look at the history. The majority of sources out there quote Dave Wetzel, the owner of Green Pastures (even Wikipedia does). We need something unbiased. Something original, that doesn’t have anything to do with this current situation.
I was able to find and read a text called Cod Liver Oil and Chemistry, published in 1895. It is a public domain work now, so it was available for free, in full. You can click the link to read it yourself, but it’s long. Skip the first several sections, as they describe what Norway is like, and what fishing is like, before they get down to the nitty-gritty on cod liver oil production.
Interestingly, I read somewhere that this was the book where Dave Wetzel got his process and information. If so, why not be transparent and cite it?
In the text, we learn that cod liver oil production dates back to roughly 1000. From the time CLO production began until 1853, it was indeed done in the method GP uses today. The text states that after catching, cod are split down the belly on the way back to shore. Roe and livers are tossed into separate barrels. A healthy liver is described as cream colored, fat, and extremely soft. An unhealthy liver is slimmer, harder, and reddish in color.
From the text (emphasis mine):
…they seldom find time to open their liver barrels before the month of May. By this time the livers are, of course, in an advanced stage of putrefaction. The process of disintegration results in the bursting of the walls of the hepatic cells and the escape of a certain proportion of the oil. This rises to the top, and is drawn off.
But in 1853, a man named Peter Moller invented a new process for making cod liver oil — steam production. This new method required very fresh livers, less than 12 hours old. It produced a raw, pale, medicinal oil.
The book says about the newly invented processes for extracting these pale yellow oils (emphasis mine):
The buyers, accustomed to the brown oils prepared from putrefyed livers, actually refused to believe that the odorless and almost colorless and tasteless product of the new method could be cod liver oil at all. It was only with great difficulty that they were convinced; but when at length it came to be understood that the oil really could be made without the undesirable qualities which for centuries had been supposed to be necessary — because irremovable — evils, then the whole scene changed.
This new pale-colored oil was considered better, and the only reason that “fermented” cod liver oil was ever produced was because there was no better method. It was considered undesirable but necessary, was knowingly produced by allowing putrefaction to occur with the livers, and was quickly replaced with better methods and cleaner, healthier raw oil as soon as possible.
Why has GP substituted the word “fermented” for “putrefied” used in the book…and gone on to deny that the cod liver oil is, in fact, putrid?
The text also says:
It was these decomposition products that gave the oil what was supposed to be its characteristic brown colour and far from delightful smell and taste. They were derived from the putrefaction of the albuminous constituents of the liver, and it was very natural that they should be supposed to be part and parcel of the oil when that was obtained by leaving the livers until, by putres- cence, the hepatic cells were broken up, and the oil globules in them allowed to exude.
The book even goes on to say (emphasis mine):
The introduction of the steam process, however, showed that these products of putrefaction were not an essential constituent of cod-liver oil from the chemical point of view ; and from the therapeutical, subsequent experience has shown that they have nothing to do with the beneficial action of the oil, if indeed they do not detract from it.
By 1894, the newer methods had taken over in Norway. Almost all cod liver oil produced for medicinal use was of the pale variety. It’s likely that this is the variety that Dr. Price would have run across in his travels, and likely the type he recommended.
It appears that GP read the text, substituted “putrefaction” for “fermentation,” and promoted it as an old-world method that was superior. I believe they actually believed that; but I think doing so was an error. The text is clear that the by-products of putrefaction were undesirable.
However, the fact that people used CLO as a remedy for hundreds of years using that method shows that it is not inherently dangerous, and has benefits. It likely just comes with certain drawbacks vs. the pale-colored, fresh CLO. This is why so many people have still experienced benefit from GP’s products.
This doesn’t, however, make them “superior” or “the best CLO” as advertised. Let’s take a quick look at what modern science says about oxidation and the by-products of such a production method.
First we need to understand what oxidation is, and why it matters with fats. All information about oxidation is taken from here.
Oxidation is the process by which fats break down, due to exposure to oxygen. It happens to all oils and cannot be stopped, but it can be minimized/slowed when oils are processed very carefully. It happens most quickly to oils that are mostly polyunsaturated, because their oils are the most fragile. This is especially an issue for marine oils (like fish and cod liver oils).
Oxidation occurs more rapidly when there is heat, light, moisture, and oxygen exposure. (It’s why most vegetable oils on the grocery store shelves are already rancid when you buy them.)
Signs of primary (early) oxidation:
- Free fatty acids
Signs of secondary oxidation:
There is also tertiary oxidation, or late oxidation.
Let’s look at peroxide values first. The source I cited above states that peroxide values (PV) should be less than 10, and possibly as low as 2. According to Green Pastures’ recent rebuttal, their oil has a high of 20, and a low of around 10 in their tests. This places them on the high side, and shows some rancidity. The long-term PV test shows them peaking around 10 (after 12 months), and then dropping back down to almost nothing by 2 years (which, from what my source says, shows significant rancidity, as PV values drop as they turn into other components).
Green Pastures’ Anisidine levels measure between 3 and 7 over time, according to their data. This is rather odd, because the source I cite above states that a value of less than 30 is ideal, and “as low as 10” may be required. GP’s values are incredibly low.
The test data we have from GP doesn’t make sense — for early oxidation/rancidity. But, we don’t have enough evidence to definitively know what’s going on right now. The evidence points to rancidity but it’s not fully conclusive. We need to test for products of secondary and tertiary oxidation to get a better idea of what’s happening. Historical data supports the idea that it’s rancid, but modern science hasn’t shown for sure.
Let’s take a look now at nutritional profiles.
The two most common species of fish that are used for cod liver oil are the Alaskan pollock, and true cod. The analysis for expected nutrition is from this book. A lot of people have said that the pollock are a type of cod, so it doesn’t really matter which was used. But, in fact, it does. As seen below, the nutritional profiles of the two fish are not the same. Pollock is much lower in the key omega-3s.
Alaskan pollock liver oil analysis:
- A member of the Gadidae family (Gadus chalcogrammus)
- 15% saturated fat
- 50% monounsaturated fat
- 15% omega-3 (13% EPA and DHA)
Iceland cod liver oil analysis:
- A member of the Gadidae family (Gadus morhua)
- 18% saturated fat
- 53% monounsaturated fat
- 24% omega-3s (23% EPA and DHA)
- EPA: DHA ration of 3:5
Brands of CLO
What we need to know now is — how do the major brands of CLO stand up to the expected analysis? Do they contain the right amounts of nutrients, in the right proportions?
I’m going to list all the info for every brand, grouped by “not recommended,” “good,” and “best.” I’ll also give notes on what I think of the brand based on this analysis. All of these are analyzed based on a 1-tsp. serving (5 grams).
Vital Nutrients (Gadus morhua)
- Total fat: 4g
- 0.5g saturated fat
- 2g monounsaturated fat
- 1200 mg omega-3s
- 320 – 510 mg EPA
- 460 – 640 mg DHA
- Vitamin A: 1800 IU
- Vitamin D: 180 IU
- PRICING: Unknown, please find a health practitioner who offers this
This brand is only available to health practitioners. The EPA + DHA ratio is 19.5% – 28.8%. The EPA: DHA ratio is roughly 7:10 which is close. This type, if available, appears to be an excellent choice. The only small red flag is that the A:D ration is exactly 10:1, which is considered “optimal.” It has likely been standarized to be this way, meaning some processing likely occurred.
Rosita (Gadus morhua)
- Total fat: 4.5g
- Saturated fat: 0.9g
- Total omega-3s: 1460 mg
- 500 mg EPA
- 710 mg DHA
- Vitamin A: 3000 – 5000 IU
- Vitamin D: 400 – 500 IU
- PRICING: $50 for 150 mL (5 oz.)
It was difficult to find information for this brand, and I spent quite a bit of time searching their site. It’s all buried somewhere, but not easily accessible as it should be. This seems a bit secretive and annoying. The DHA + EPA percentage is 26%. which is high even for true cod. The EPA: DHA is about 5:7, which isn’t quite right. It seems to be a very good choice, though. The ranges of A:D are within what we would expect for this type of fish and the ratios are close but not exact — meaning they likely haven’t been altered.
Dropi (where to buy) (Gadus morhua)
- Total fat: 4.6g
- Saturated fat: 0.8g
- Monounsaturated fat: 2.3g
- Total omega-3s: 1150 mg
- 450 DHA
- 350 EPA
- Vitamin A: 2417 IU
- Vitamin D: 172 IU
- PRICING: $53 for 220 mL (7.3 oz)
Cod liver oil is cold-pressed and not refined or processed. This brand is coming to the US in September. The EPA + DHA percentage is 17.4%. The EPA:DHA is 7:9 which is a little off, but not much. The A:D ratio is a little off, and a little low, but I translated these numbers from ug, so it’s possible they may be a little off — they’re close to what we’d expect, though.
NutraPro International (they confirmed they only use Gadus Morhua)
- Total fat: 5g
- Saturated fat: 1g
- Total omega-3s: 600 mg
- 700 DHA
- 500 EPA
- Vitamin A: 2500 IU
- Vitamin D: 250 IU
- PRICING: $33 for 8 oz.
Edited: The company contacted me and pointed out that the DHA and EPA levels were incorrect. They are actually what is now listed. The company had switched the EPA and DHA levels on the labels, and I forgot to double them to account for serving size. It’s now 24%, which is a little high but pretty close to right. It’s also got a ratio of 5:7 which is fairly close. They also confirmed that they only use Gadus Morhua. The A:D is also 10:1, suggested that it’s been standardized, and both are on the low side.
Carlson’s (fish type not stated)
- Total fat: 5g
- Saturated fat: 1g
- Monounsaturated fat: ?
- Total omega-3s: 1100 mg
- 500 DHA
- 400 EPA
- Vitamin A: 850 IU
- Vitamin D: 450 IU
- PRICING: $30 for 500 mL (16.7 oz)
Oil is extracted through steaming, which is a traditional method but not the optimal choice. The vitamin A:D ratio is concerning as well, it’s almost 2:1 when it should be closer to 10:1. The EPA + DHA is 18%, which is lower than we’d expect for true cod, and higher than for pollock. EPA:DHA is 4:5 which is off.
Sonne’s(fish source not stated)
- Total fat: 4g
- Saturated fat: 1g
- Monounsaturated fat: 2g
- Total omega-3s: 1000 mg
- 440 mg EPA
- 440 mg DHA
- Vitamin A: 4000 IU
- Vitamin D: 400 IU
- PRICING: $17 for 16 oz.
This cod liver oil says that it’s from Norwegian cod, but doesn’t state which variety. Its EPA:DHA is way off, at 1:1. The A:D is exactly 10:1, which means it’s likely standardized. The amounts of omega-3s and vitamins are good, though. It is also purified by molecular distillation (which means the vitamins are likely added/synthetic).
Garden of Life (cod source not named)
- Total fat: 4.5g
- Saturated fat: 1g
- Total omega-3s: 1400 mg
- 400 DHA
- 447 EPA
- Vitamin A: 4500 IU
- Vitamin D: 450 IU
The DHA + EPA percentage is 18.8%. The EPA:DHA is almost 5:4 which is way off. The A:D ratio is exactly 10:1 which likely means it has been standardized. This may well have been refined in some manner, and is likely a mix of different fish.
Nordic Naturals (fish type not stated)
- Total fat: 5g
- Saturated fat: 1g
- Monounsaturated fat: ?
- Total omega-3s: 1050 mg
- 485 DHA
- 350 EPA
- Vitamin A: 425 – 2950 IU
- Vitamin D: 0 – 20 IU
Their ingredients include “purified arctic cod liver oil” which means some type of refining has occurred. Baby versions use soybean oil mixed in. The percent of EPA + DHA is 16.7%, which is close to what we’d expect for pollock, and much lower than what we’d expect for true cod. The EPA:DHA is 7:10, which is close. A and D are incredibly low, especially D! Basically no benefit in this area. I would absolutely not recommend this.
Green Pastures (fish source not stated; thought to be Alaskan pollock)
- Total fat: 5g
- Saturated fat: 1g
- Monounsaturated fat: ?
- Total omega-3s: 21.2%
- 5.8% DHA
- 12% EPA
- Vitamin A: 2350 IU
- Vitamin D: 980 IU
Most of the data is not included on the product label (except total and saturated fat) and has been pulled from their test results here. This has about 17% DHA and EPA, which is more than we’d expect from pollock (around 13%), but less than we’d expect from true cod (around 23%). This may mean a mix of different fish. EPA:DHA is almost 2:1 which is extremely far off. A:D ratio is rather high, and D especially is very high for what we’d expect. There is no evidence that D is increased by their “fermentation” process, although a lot of people have speculated or assumed this.
So how did this all happen?
We’ve come to trust “natural” and “traditional/ancient” processes more than we do more modern processes. And usually, that’s a good thing!
We also have come to believe that color is a sign of nutrition and health benefits. We’ve believed that the more pale something is, the more it lacks nutrition — or, it may have even been bleached or deodorized to obtain that pale color. We’ve seen other CLO and fish oil brands advertise their amber color vs. others’ nearly clear color as being better because it’s obvious that it’s unrefined. So, the “color scheme” played a big role.
And, we’ve come to believe that “fermentation” is always a good thing. Which it is, when it produces those awesome strains of bacteria that help our guts! But this is not one of those cases.
All of these combined to make FCLO seem like the perfect product. It was using an ancient process, it was dark in color, and it was supposedly “fermented.” All the things we typically look for in a super food!
Only, most of us had no idea what to really look for in a quality CLO. And in fact, “best practices” for CLO don’t match the above criteria! Instead, we have to look at the nutritional analysis, and we have to look for rapid cold-pressing and careful handling (which produces that pale oil). Both the historical text and modern science support this.
I believe everyone got a little carried away by the traditional/color/fermentation issues — including GP itself. And I believe that for many people, FCLO can and did produce good results. Cod liver oil is that powerful and that amazing that even produced through allowing livers to putrefy, it still has health benefits. But, many people are also very sensitive to the by-products of this method, and experienced serious drawbacks.
I can’t say that you “must” stop taking FCLO if you believe it is best for you. I would advise serious caution, though. And I would never advise anyone who felt they were reacting badly to keep trying it — look for another brand! I will definitely be looking for another brand for my family — one of the ones I listed above. Once I’ve had a chance to try it, I’ll report on how we’re liking it.
DO any of the brands offer a variety that includes the butter oil, to get the synergy from cod liver oil and butter? Or would you just recommend taking it with a meal that includes grassfed butter, as I think you did when you first starting taking CLO?
[…] the follow-up post, How to Choose and Understand Cod Liver Oil, for more […]
Wow… excellent article. Glad you mentioned NutraPro as it’s listed as ‘best’ choice from WAPF (a bit pricey). I’ll be striking that one off my list as well as TwinLabs (listed as ‘good’ choice: EPA is 1.5 times DHA though A to D ratio seems good). Any thoughts on Nature’s Answer? Again listed as ‘best’ choice from WAPF, A is 4000 IU, D is 430 IU, DHA is 460 and EPA is 430. The numbers look good to me… I’m keeping Sonne’s and Rosita on my list (though Rosita better taste awesome (or not at all) for the price they want… I may wind up circulating between the 2-3 brands I pick in the end. Thanks again for doing this analysis – very helpful.
Thank you so much for this analysis! I will definitely share it with others.
Thank you for putting together this post. A couple days ago I made a call to Nutrapro and in that conversation, the man stated that Rosita and Nutrapro get their cod from the same place in Norway. He assured me that buying from nutrapro was the same, if not better (because he does the processing himself) than Rosita. I’m not sure what to believe and I don’t want to have wasted another $80 on CLO and butter oil! I’m wondering if there is a way to find out the validity in what he is saying? This is getting so confusing!
Thanks. Great review. It would be interesting to have a cost comparison included in your comparison of CLO products – I guess I want you to do ALL the work for me!
Hello Kate, I`m from Norway and just want to inform you that Rosita oil was tested by Norwegian food department and the result showed high and dangerous content of PCB and dioksines. I do not recomend you to use this oil. Here is a link to an article, hope you are able to translate it into you language as it is written in norwegian:
It’s not an accurate statement to say that David Wetzel isn’t admitting where he got his information and process. He actually cites it in this article he wrote for Wise Tradition, back in … 2006, yes 2006! http://www.westonaprice.org/health-topics/cod-liver-oil-manufacturing/ 9 years ago he talked about the process and where he got the information. I don’t know how this could get missed but then with all the brouhaha…
I know that my daughter has responded very well to the FCLO/HVBO combination (since before we knew about her allergy), and as she has an anaphylactic reaction to all other dairy, that’s saying something. I’m not sure I would trust any other option, and certainly wouldn’t feel comfortable just handing her a spoon of plain grassfed butter. Something about the combination and quantity must inherently work. I myself have used it to successfully chase away stomach viruses and other issues. We have quite a bit left and I don’t plan to chuck mine in the trash like all the other knee-jerkers out there.
I think this whole thing has gotten blown WAY out of proportion and has villainized someone that doesn’t deserve such a negative response. Given how big it got I wouldn’t be surprised that he couldn’t sue for libel and damages, and win. I’m disappointed in most of the whole food community and many of my favorite bloggers for jumping on the bandwagon instead of stepping back and looking at the bigger picture. I’m glad that this website at least takes a more objective view than most. Kudos.
I don’t take any cod liver oils anymore. But I would say that I contacted NutraPro some while back asking them why they had copied the Rosita labelling (I am very suspicious of companies that copy others and if you look carefully you will see that Dropi has copied Rosita too including using the word “ancient” technique and showing a very similar video to theirs). NutraPro actually replied, did not explain why they copied, but simply said that Rosita was a very different oil to theirs and was “Extra” Virgin and not simply “Virgin” like theirs was. They seemed to be saying that their brand was not as good. I still have their email.
Dropi was actually founded by 2 businesswomen who obviously saw the potential to make money.
After the shocking revelations about FCLO I for one will not take any more cod liver oil but will eat organ meats, fish and eggs instead. My husband is very pleased with that choice! Good summary by the way.
I’m not going offer an opinion on the current controversy as that’s all it would be . . . an opinion. Few, if any of us, really know the facts at this point. I would point out though if they are using any Alaskan Pollock at all mixed with Icelandic Cod, I would have a huge concern about the radiation levels in any fish from Alaska right now as Fukushima continues to dump nuclear waste into the ocean every day.
I was wondering if you ever heard of the brand, Standard Process. They carry a line of Cod Liver Oil capsules and a couple people including my husband’s chiropractor recommended it! Wondering if it’s another one worth adding to your list or not?!
Oh my goodness….last year I was a little pinched for cash, so I switched from GP FCLO to Sonne’s CLO. Everytime I took it, I was on the toilet for 2 hours at a time with liquid stools. The cramps associated with it were excruciating! My other family members, however, did great on it. Perhaps it was the synthetic A & D I was sensitive to? Not sure. Never really had a problem with GP, although sometimes it made my stomach sour, but it was nothing a small piece of ginger couldn’t cure.
I came across this article about contamination in the Rosita brand and some others, what do you make of it?
I would like to take cod liver oil, but I will not until I can confirm that the source of fish is NOT from the Pacific Ocean. With Fukushima being an ongoing problem, this is a real concern!
You obviously put a lot of work into this, and I applaud the effort, but I think you may be stating things overly confidently that you don’t have full understanding of. I encourage you and your readers to see Chris Masterjohn’s very informative post on the great FCLO debate, which will help you understand the terms you are using such as “rancid,” “rancidity,” and “fermented.” These terms are all in general use in a non-technical sense, and they have different technical meanings, depending on the scientific discipline using them.
Any given supplement is not going to suit everybody; some do well on FCLO, some will do better on EVCLO. The oils that have been deodorized with the vitamin content destroyed or removed and partially replaced by synthetic vitamins are especially poor choices, no matter how palatable they may be. Just because something smells or tastes bad does not mean it is not healthful. That’s a good standard when it comes to deciding whether leftovers at the back of your fridge are still edible, but when it comes to inherently stinky foods like some aged cheeses, natto, and cod liver oil, that’s not a helpful measure.
Well no response on a refund from GP. Why did i get sucked in by this sheet. 500 dollars down the drain.
“If it tastes like sheet, smells like sheet then it is sheet”.
I have been told that it is a mistake to use “label data” to compare different oils. It is important to understand that the number on the label can’t represent the true number of the product. The number on the label is based on statistic analysis of your past products, however, due to different variations, such as season, feed, harvesting location, etc, the vitamins, EPA/DHA, even the polyunsaturated fatty acids will be varied. Sometimes the seasonal variations can be larger than the different fish species. That is the reason all scientific papers and other official documents, such as FAO Codex gives the range of those nutrients instead of a certain number. If you find the exact number in one product for different batches, that may mean the producer adds something to standardize the ration to meet their standard.
First of all, Vital Nutrients CLO is now available through Swanson’s for $20.70 per 200mL (6.76 oz.) bottle.
Second, can someone please explain to me how the exact same species of fish (i.e. gadus morhua) can have such drastically different amounts of Vit D? Vital Nutrents and Dropi’s both have ~ 180 IU, but then Rosita’s supposedly has 400-500 IU?!! That doesn’t make any sense to me!! Please help! Thank you.
My son was diagnosed with autism last year and since the diagnose we places him on a strict diet and added supplement. Our big problem is the fatty acids, I was trying to find mercury free cod liver oil and I was always told that the best out there for toddlers is Nordic Naturals. I’m a bit confused and its hard to get an honest or knowledgeable answer from his doctors. What would you recommend ?
I see that Vital Nutrients is now availalbe on Amazon and pureformulas
I used to take CLO but my Naturopath is completely opposed to anyone taking Cod Liver Oil now because it all has some content of mercury in it and no amount of mercury is acceptable. He much prefers a weekly meal of organic, grass fed liver and small daily amount of organic grass fed butter. I also used to enjoy adding seaweed to my diet for the iodine but we have polluted our water so badly that I have stopped doing that as well not knowing what could be in it.
I am looking for capsules as we can’t stomach the taste of the CLO. Any of these recommended ones come in pills?
[…] But, I looked into it more, and discovered — unfortunately — that there was a legitimate concern. Read my take on all of the controversy. Plus, my original follow-up on how to choose quality cod liver oil. […]
Is the Dropi deal still available? It doesn’t say how many people are needed by 2/8.
Great information! This is so helpful. Thanks for sharing!
However, you stated that “Interestingly, I read somewhere that this was the book where Dave Wetzel got his process and information. If so, why not be transparent and cite it?” Please note, he did cite it in Wise Traditions in 2006, which you can read here: https://web.archive.org/web/20150108142530/http://www.westonaprice.org/health-topics/cod-liver-oil-manufacturing
Hi! I was wondering which extra virgin cod liver you preferred… Rosita or Dropi. Even with my healthcare professional discount, Dropi comes out cheaper. The differences in both are that Rosita says they use a “rare ancient” extraction method that doesn’t require heat, whereass Dropi is cold pressed. Have you tried either? I heard Dropi is better, but it’s really getting me to think… thanks for your help! Great blog!
Oops, you need to change the omega 3 in Nutrapro brand to 1200mg for a teaspoon. In the info you still show 600mg which is what is just for 1/2 teaspoon. Thanks for caring to do a comparison for all these cod liver oils! 🙂
Do you know any thing about Innate Choice?
How would Innate Choice Cod Liver Oil compare to Rositas Extra Virgin Cod Liver Oil?
[…] or otherwise altering or preserving it may cause rancidity and ruin its effects. This is you should do your research, and purchase a CLO which is sustainably-made and minimally processed. Other fish and vegetable […]
[…] forget the vitamin D. Best form of supplementation is fish liver. I personally like cod liver oil. If you live in a cold climate and don’t get a lot of […]
I wanted to start taking cod liver oil, but im so confused that I don’t know what to get…….I am type 2 diabetic, high blood presser, high cholestoral, I take meds for it all, omega 3’s 6 per day. I want to get of it all……but, now i’m so confused as what to do or take. a woman on Home and Family says cold liver oil is good for your hair. really? my daddy gave it to us when we were children to keep us from getting colds….awful stuff. thanks Grandmommy