Omega 3 & DHA (original) (raw)
Omega 3 & DHAJeff2021-05-31T21:25:18+00:00
Omega 3 & DHA
Should You Worry About DHA?
by Jeff Nelson
Do vegans need to be concerned about omega-3 fats? Should they take DHA supplements?
The answer to both questions is: No.
Why do some in the vegan world say you should worry about omega 3 and DHA?
Largely because businesses which profit from the sales of omega 3 supplements and tests have produced research to try to make their products look necessary. They point to a few studies showing vegans may have lower omega 3 blood levels than omnivores – and ignore studies that show the opposite.
Recently researchers involved in selling DHA supplements have tried to convince potential customers that having “higher” blood levels of omega 3 is beneficial to brain health, and that “low” levels are a risk factor. This is based on very weak, contradictory research – tied to the DHA business. They assert that “risk of dementia and Alzheimers” can be lowered by DHA supplements – and fail to produce any credible research to back this up.
I show a number of points on this page that debunk these notions, such as the fact that healthy vegans have been shown to have HIGHER blood levels of omega 3 than omnivores who consume fish (study from Joel Fuhrman MD) – not lower.
It’s important to realize that there is no standardized testing for omega 3 blood levels. You can send the same blood sample to 5 different labs, and get very different scores from each – by a factor of 3.5. We show the published research further down the page.
Omega 3 blood testing is not FDA approved and standardized like cholesterol or lipid tests. These are tests done by labs using wildly varying references, most set by omega 3 industry-related studies. Each lab has references set by different parameters. This is not a credible or useful test.
The research cited by people who sell DHA – or by vegan MDs like Michael Greger and a few others recommending it – has been conducted by people with a financial interest in the outcomes – they sell DHA or Omega 3 blood tests. This is not serious research, and is explicitly rejected by every top dementia expert, as I’ll show.
Omega 3 and Dementia
Let’s start by noting that none of the professional medical organizations which produce guidelines on the treatment or prevention of dementia – none recommend worrying about omega-3s or taking DHA supplements.
For example, guidelines from the WHO, the Alzheimer’s Association, the National Academies of Science, the Lancet commission, and guidelines on dementia from Canada – none makes any mention about DHA possibly being helpful. None have suggested vegans or anyone else need to be concerned about omega-3s, or that a theoretical “deficiency” of DHA could contribute to or cause dementia.
The WHO committee – comprised of 21 of the top neurologists in the world – go a step further. They explicitly recommends against taking DHA to prevent dementia.
So there is no neurological or any major medical body anywhere in the world that recommends DHA supplements for dementia prevention. Here are those guidelines, if you wish to check:
https://www.who.int/mental_health/neurology/dementia/guidelines_risk_reduction/en/
www.alz.org/media/documents/alzheimers-facts-and-figures-2019-r.pdf
https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(17)31756-7/fulltext
https://www.nap.edu/resource/24782/Highlights062217CognitiveImpairment.pdf
Here is the largest analysis ever performed on prevention of Alzheimer’s disease, with 21 recommendations, ranging from weak evidence to strong evidence. DHA supplements (including fish oil) did not make the list at all:
https://jnnp.bmj.com/content/early/2020/06/01/jnnp-2019-321913
The most recent review from the Lancet (August 2020) talks about what you can do to help prevent mental decline – DHA supplements did not make the list.
https://www.thelancet.com/action/showPdf?pii=S0140-6736%2820%2930367-6
Here is a very recent study where they gave people DHA supplements and then actually measured how much was getting to their brain. No study had ever looked at this before. How much DHA in a supplement reaches your brain? The answer according to the researchers: extremely little. Moreover, very high doses (many times what is sold to the public in supplements) would be needed to get any amount into your brain.
https://www.sciencedirect.com/science/article/pii/S2352396420302589
Study: Healthy Vegans Have Higher Omega 3 Levels Than Omnivores
It’s important to note that healthy vegans have actually been found in research to have HIGHER blood levels of Omega-3 than omnivores. Joel Fuhrman MD showed this in a DHA study that he funded, using the DHA product that he sells. (Dr. Fuhrman sells his own private-label brand of DHA, and finances studies to try to market it to vegans.)
I am personally aware of the health of many of the subjects who participated in Dr. Fuhrman’s study – many of the people who enrolled in his study followed a McDougall diet. If you look at the study, you will see researchers listed my website vegsource.com as a major source of study participants – see image. Dr. Fuhrman asked for my help to recruit participants since many of his followers already purchased his DHA product, and were thus ineligible to be in his study.
Dr Fuhrman’s study showed healthy vegans have higher Omega-3 blood levels than omnivores. Fuhrman had previously written many times that vegans have lower omega-3 levels than omnivores and thus should be very concerned.
But his own study showed that the vegans he tested had a mean omega 3 blood level of 3.7%, while a group of omnivores from another study Fuhrman’s researchers selected for comparison – had a mean omega-3 blood level of 3.45%. So a group of omnivores – who all ate fish and shellfish according to the study cited by Furhman – had lower omega 3 blood levels than healthy low-fat vegans.
In fact, rather than mention that the vegans actually had higher omega 3 levels, the Fuhrman researchers state that vegans had “low” baseline levels, “but not lower than omnivores who also consumer very little DHA and EPA.”
Not only did the vegan group have higher omega-3 blood levels, it was disingenuous for Fuhrman’s researchers to assert that the omnivore group they selected consumed “very little DHA and EPA.” When you check the study in question, you see this statement in Fuhrman’s study is false.
Here is Fuhrman’s study, you can read that the mean omega-3 blood level for vegans at the start of his study was 3.7%:
https://www.sciencedirect.com/science/article/pii/S0261561414000764#bib10
And here is the study of fish-eating omnivores Fuhrman’s researchers selected to use as a comparison with his vegan group. (Both studies used the same omega 3 blood testing system.) You can see the omnivores started with a mean omega-3 blood level of 3.45%:
https://pubmed.ncbi.nlm.nih.gov/22748167/
Full study available here: https://sci-hub.se/10.1179/1476830512y.0000000025
Prior to Fuhrman’s study there had been studies of less healthy vegans, who consume diets high in oils, nuts, and processed foods (high in omega 6 fats, which crowd out omega 3 absorption). These less healthy vegans had lower levels of omega-3 than the omnivores they were compared with. But this was not the case with the healthy lowfat vegans in Fuhrman’s study.
Is “Low” Omega-3 a Cause for Concern?
It’s important to note that having “low” omega-3 has never been identified as an actual risk for anything. Eating a junk food diet, vegan or otherwise, isn’t healthy. But it’s not something that taking an omega-3 pill would in any way impact or improve.
Is there such a thing as having “too-low levels” of DHA? The NIH has looked at the question and produced an info sheet on essential fatty acids, it says:
“There are no known cut-off concentrations of DHA or EPA below which functional endpoints, such as those for visual or neural function or for immune response, are impaired.”
https://ods.od.nih.gov/factsheets/Omega3FattyAcids-HealthProfessional/
Translation: there is no lower level of DHA or EPA in the blood that is associated with any harm – on the eyes, brain, or immune system.
In fact, having higher levels of omega-3 fats in your blood may in fact raise risk of cancer. There’s a growing body of research on this, which is covered further down this page in both text and in the videos there.
DHA-pushers Are Using Amateur-hour Blood Tests
Anyone listening to gurus pushing DHA needs to understand that there is no established, standardized measurement of omega 3 in blood. Labs don’t agree on how to measure it. This is not an area like cholesterol where everyone agrees on a standard measurement and what it means.
So what is the “desirable” blood level of omega 3? It depends who you ask.
Quest, the nation’s largest laboratory, says greater than 3.2% is “optimal” see:
Dr Joel Fuhrman’s study on DHA says “assuming under 4% [blood level] to be undesirable…” Why did Dr Fuhrman make the assumption that under 4% is not desirable? Why does Dr. Fuhrman believe that Quest is wrong? There’s no explanation in Fuhrman’s study of why or how he came up with his cut-off.
It appears to be a number Fuhrman has simply invented which happens to create a “deficiency” in both vegans and omnivores. Fortunately Dr. Fuhrman can “fix” the problem with the special private-label DHA pills he used in his study – and which he conveniently markets in his online store for 57permonthandofferswithauto−shipsoyoucangetyourmonthlyrefillswithoutworry.Thisisabout57 per month and offers with auto-ship so you can get your monthly refills without worry. This is about 57permonthandofferswithauto−shipsoyoucangetyourmonthlyrefillswithoutworry.Thisisabout700 per year Dr. Fuhrman is suggesting you spend in his store to address a very theoretical “deficiency.”
William Harris MD is deeply involved in the omega 3 business. He owns an omega 3 testing lab, where he earns millions selling tests. He is also on the board of a DHA fish oil supplement company. Dr. Harris was involved in Dr. Fuhrman’s study and provided the omega 3 tests used by Fuhrman. (Dr. Harris is involved if many – if not most – of the omega 3 studies done in the past couple decades.) Dr. Harris says your Omega-3 blood level should be >8%.
While Quest sets “desirable” omega 3 blood levels at 3.2% or greater, Harris and Fuhrman – both of whom profit from DHA – set higher levels for “adequacy.”
Omega 3 Blood Testing Isn’t Reliable or Consistent
Every lab doing omega 3 blood testing – gives wildly different results, different numbers with the same blood sample. Harris himself admits this on his website where he sells is omega-3 blood test:
Other fatty acid tests do not use the same analysis methods and cannot be interchanged with the Omega-3 Index. So your EPA+DHA, for example, might be 6.7% in Lab A and 5.2% in Lab B. Which one is “right?”
In a review paid for by Harris, it was noted that:
In fatty acid analysis, methods have a large impact on results: when one sample was sent to five different laboratories offering determination of an Omega-3 Index, results differed by a factor of 3.5 [34]. While results may be internally valid in one laboratory, a difference by a factor of 3.5 makes it impossible to compare results among laboratories.
So Dr. Harris says if you send your blood sample to five different labs, you will get five different answers. Does this sound like a serious, reputable test? And the results will differ by a factor of 3.5 – three and a half times higher at one lab than another.
To review – Harris sets >8% as “desirable” as his reference. Fuhrman used Harris’ omega 3 blood test but disagrees with Harris’ >8% reference, and invented his own reference of >4% as “desirable.” Quest’s reference finds >3.2% as “optimal.” Then there are European omega 3 labs which use different testing modalities and have their own unique levels. And what most of these places all have in common is they are related or connected to companies that make money selling DHA.
This is what happens when a test has not been proven to mean anything and does not have FDA approval – unlike a CBC, lipid panel, TSH, and other credible tests.
This is supplement-industry “science” – from people actively making money off DHA supplements and funding “research” to try to create “science” for marketing purposes.
No Omega 3 References Based on Dementia Risk
To come up with his omega 3 blood level reference, Harris used a study of 992 people (80% men), average age 67, all of them had heart disease and the majority were taking multiple medications like beta-blockers, statins, ACE-inhibitors and aspirin. Here’s the study group Harris states he used to create his reference range:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2717185/
Quest used a younger and much healthier group – 22,000 men average age 57 at time of study, followed over 17 years in the Physicians Health Study. None of the participants had heart disease at the start. So the lower omega 3 reference from Quest is based on a much larger, younger and healthier population than Harris, which probably makes Quest’s reference a lot more reliable. Here is the study Quest used:
https://www.nejm.org/doi/full/10.1056/NEJMoa012918
And of course all these references for omega-3 blood levels – were created for CVD risk, not for dementia risk.
To my knowledge, no one has gone in and set references for omega 3 and dementia using studies of dementia patients. It’s just a bunch of weak assumptions about “brain volume” and other indirect associations – made by people who make money selling tests and DHA.
It’s one set of assumptions on top of another, on top of fundamental unproven speculation – that DHA supplements might actually confer a benefit for brain health. Not to mention, the industry studies purporting to show some benefit of omega-3 supplementation all used much higher doses than what people like Fuhrman and Harris sell, often by a factor of 10 to 16x.
The Framingham Brain Volume Study Was Conducted by Dr. Harris (who profits from the results)
A principal study cited by vegan DHA-pushing doctors, including Michael Greger of Nutrition Facts, was done by the DHA-peddler Harris using data from the Framingham study. It was not a study that looked at dementia in any way, but at brain volume. It was a cross-sectional study using Framingham data that examined blood DHA levels in relation to changes on MRI and tests of visual memory, executive function, and abstract thinking.
In this convoluted study Harris looked at participants’ blood levels of omega 3 eight years earlier – and compared them with the individual’s brain volume today, along with certain memory tests. He found an association of those having lower omega 3 blood levels 8 years earlier having lower brain volume today.
But the difference was miniscule, and clinically unimportant. It was in no way sufficient evidence for any professional to recommend DHA for dementia prevention.
This is the study: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3286229/
To confirm this is an unimpressive study, I asked one of the top brain volume experts in the world – who also serves on the WHO’s expert committee which creates WHO guidelines on dementia – a neurolorigst named Darren Gitleman MD – his opinion on Harris’ Framingham DHA study.
Here is what Dr. Gitleman wrote:
The study is interesting, but does not provide sufficient evidence to justify treating patients with DHA to prevent dementia. In brief, here are my thoughts.
- The study is retrospective and not prospective. Therefore, it is difficult to provide appropriate controls and to have the strongest evidence that the intervention makes a clinical difference.
- The study examined brain volumes and cognitive performance, not the development of dementia. While we think that people with lower brain volumes and lower cognitive performance may be more likely to get dementia, the study has not actually addressed the issue of dementia.
- Although the results are significant, this is probably due to the large sample size. Calculating a Cohen’s d (effect size) of the results for brain volumes, for example, gives a value of 0.06, which is very tiny, suggesting not much of an effect.
Bottom line, DHA is unlikely to prevent dementia.
Dr. Gitleman notes the “Cohen’s d” (effect size) is “very tiny” at 0.06. This means that if there is any relationship between omega 3 blood level and brain volume 8 years later, it’s barely nothing.
To understand the significance of Cohen’s D: a calculation of 0.2 is considered a ‘small’ effect size, 0.5 represents a ‘medium’ effect size and 0.8 a ‘large’ effect size. The effect size Harris found in his Framingham study of 0.06 – is so small a change as to be irrelevant. (To learn more about Cohen’s d and what it means, click here.)
Your Omega 3 Blood Levels Can Vary Widely Over Short Periods of Time
Moreover the idea that a person’s omega 3 blood level eight years ago had any relevance to brain volume today – is shown to be nonsense – because your omega 3 blood levels can change all the time. All you have to do is look at the omnivore DHA research Dr. Fuhrman used to compare to his group of healthy vegans for his DHA study.
Harris used the same study participants and published a second study called: Effects of Omega-3 Fatty Acid Supplementation on Neurocognitive Functioning and Mood in Deployed U.S. Soldiers: A Pilot Study. The full study is available here:
https://academic.oup.com/milmed/article/179/4/396/4160759
At the start of the study, researchers found a mean omega 3 blood level of 3.4% in the placebo group. After 60 days when participants were re-tested for omega-3 blood levels, the placebo group’s levels went from 3.4% to 4.2% – without any DHA supplementation.
This shows that one’s blood levels of omega-3 can change significantly over short periods of time. A reading of 3.4% this month, can turn into 4.2% a couple of months later, without taking any expensive DHA supplements.
Here is the table from this omnivore study noting the increase in omega-3 in the placebo group in 60 days – without receiving any DHA supplement:
Again, this shows that one’s omega-3 blood levels can vary significantly over a short period of time (60 days).
Thus, in the Framingham study, cited by some vegan doctors, that tried to correlate one omega-3 blood test from eight years earlier, to brain volumes eight years later – is completely meaningless, based on how changeable one’s omega 3 blood levels are over short time spans.
And again, the variety of the non-standardized testing systems used to measure omega-3 blood levels – underscore that you are going down a corporate-sales rabbit hole, and not getting anything clinically relevant. In fact, these tests aren’t taken seriously in the medical field and few, if any, reputable doctors ever order omega-3 tests for their patients.
DHA Supplements May Promote Prostate Cancer
Researchers at Fred Hutchinson – a respected cancer research org in Seattle – first reported on the association between higher blood levels of omega-3 and prostate cancer, in 2011:
A high percentage of omega-3 fatty acids in the blood is linked to an increased risk of aggressive prostate cancer
Analyzing data from a nationwide study involving more than 3,400 men, researchers at Fred Hutchinson Cancer Research Center found that men with the highest blood percentages of docosahexaenoic acid, or DHA, an inflammation-lowering omega-3 fatty acid commonly found in fatty fish, have two-and-a-half-times the risk of developing aggressive, high-grade prostate cancer compared to men with the lowest DHA levels.
A few years later another study with similar findings:
https://www.fredhutch.org/en/news/releases/2013/07/omega-three-fatty-acids-risk-prostate-cancer.html
Link between high blood levels of omega-3 fatty acids and prostate cancer – Fred Hutchinson Cancer Research Center
Consumption of fatty fish and fish-oil supplements linked to 71 percent higher risk
A second large, prospective study by scientists at Fred Hutchinson Cancer Research Center has confirmed the link between high blood concentrations of omega-3 fatty acids and an increased risk of prostate cancer.
Published in the online edition of the Journal of the National Cancer Institute, the latest findings indicate that high concentrations of EPA, DPA and DHA – the three anti-inflammatory and metabolically related fatty acids derived from fatty fish and fish-oil supplements – are associated with a 71 percent increased risk of high-grade prostate cancer. The study also found a 44 percent increase in the risk of low-grade prostate cancer and an overall 43 percent increase in risk for all prostate cancers.
The increase in risk for high-grade prostate cancer is important because those tumors are more likely to be fatal.
Newer studies have found the same troubling trends.
Plasma Phospholipid Fatty Acids and Prostate Cancer Risk in the SELECT Trial:
This study confirms previous reports of increased prostate cancer risk among men with high blood concentrations of LCω-3PUFA. The consistency of these findings suggests that these fatty acids are involved in prostate tumorigenesis. Recommendations to increase LCω-3PUFA intake should consider its potential risks.
https://academic.oup.com/jnci/article/105/15/1132/926341
So they cautioned against potential elevated risks of the long chain omega-3’s which are EPA and DHA. And that men should consider the risk before they start trying to raise their omega 3 blood levels.
Another study – Fatty acid composition of plasma phospholipids and risk of prostate cancer in a case-control analysis nested within the European Prospective Investigation into Cancer and Nutrition:
There were significant positive associations between myristic, alpha-linolenic, and eicosapentaenoic acids and risk of high-grade prostate cancer.
CONCLUSION: The associations between palmitic, stearic, myristic, alpha-linolenic, and eicosapentaenoic acids and prostate cancer risk may reflect differences in intake or metabolism of these fatty acids between the precancer cases and controls and should be explored further.
https://www.ncbi.nlm.nih.gov/m/pubmed/18996872/?i=6&from=crowe%20fl%20and%20prostate%20and%20fatty%20acid
Watch the videos below for many more studies on this.
Think about the folly of suggesting someone take a supplement that appears to increase cancer risk, like DHA.
We know higher beta-carotene blood levels are associated with much better health outcomes. Following the logic of the supplement-pushers, shouldn’t we buy beta-carotene supplements to raise our beta-carotene blood levels, and thus, theoretically, lower mortality risk?
Researchers actually tested this, and we now know when researchers gave beta-cartotene supplements to study subjects – the beta-carotene supplements were shown to increase lung and prostate cancer incidence, while conferring no benefits. This is what profit-motivated speculation on supplements can sometimes lead to: cancer.
We have seen the same happen with some B vitamin supplements. Supplementing a “healthy” substance can lead to increase in fatal diseases.
Here is a researcher talking about supplement studies, where researchers originally thought they might be helpful, but actually ended up raising cancer risk. In this case he is observing about a finding that high B12 blood levels appear to cause cancer in smokers:
Langhammer says there is a tendency for people to think that the more vitamins, the better.
“But the body is a finely balanced system. You don’t need to consume more vitamins or minerals than the body actually needs, and it may be that B vitamins are of the type where it is particularly important not to take too much,” Langhammer says.
“Everything you consume as extra vitamin supplements beyond what you need for normal levels is unnecessary, and can be harmful. People who eat a varied and regular diet and live moderately, usually do well,” he said.
Amen.
To learn more, watch these videos below from Dr. Klaper and from Jeff Nelson, examining the subject of DHA supplements in greater detail.
