The Need for DHA by Vegans (Part 2)

December 20, 2019 by Joel Fuhrman, MD

Health Concerns: Brain Health and Mood

Additional reading and video content:

Read Part 1 of Dr. Fuhrman’s response to the DHA controversy:

The Need for DHA by Vegans


NOTE: This is the transcript of my YouTube video response, with references. 

DR. FUHRMAN: This YouTube video is in response to a series of videos by Jeff Nelson where he promotes his claims about dangers of taking DHA supplement for Vegans, and the worthlessness of doing so to prevent later life dementia.

I had already written an article (The Need for DHA by Vegans (and Near-Vegans) PART 1  published on my blog at in response to his prior videos that discussed this issue and many of his incorrect assertions. My previous, full referenced article challenges the ideas he presented in a manner that I had thought was adequate.

However, since Dr. Klaper, a dear colleague, was featured on Nelson’s video as no longer recommending DHA supplementation, made it evident plant-based consumers may be more confused than ever. I think this is understandable, considering the one-sided information that was presented on this issue by Jeff Nelson. What happened since the filming of that video is that Dr. Klaper has reviewed the studies I am reviewing with you today, revised his thinking, and retracted the statements featured on Jeff Nelson’s video.  

These complicated issues are made even more challenging due to the conflicting nature of some studies. The different conclusions of various studies enable people to choose whatever position they want and support it with some evidence. 

This idea that whatever the facts show – and whatever I say – is invalid because I sell a DHA supplement is not a legitimate argument.  A bias, if one existe, does not change the evidence and the facts.  Everyone giving their opinion on this issue is biased, especially the few in the vegan community who have taken a strong stance against DHA supplementation. And especially that I claim they are taking needless risks with people’s later life brain health. That is not an accusation they will readily accept without attempting a robust defense.

I am all for a healthy debate on whether a vegan should take a DHA supplement. But this has not been a civil scientific debate. Jeff Nelson has added an element of character assassination into the debate against me and other leaders in the plant-based movement, which is uncalled for. 

So, let’s try to unravel the confusion here.

The first claim made by Nelson, attacking the potential benefit of DHA for brain health, was discussing the lawsuit against CVS, who made a marketing claim that DHA supplements have been proven to improve memory.  For some reason, he is associating that claim about improving memory with my assertion that long-standing DHA deficiency can shrink the brain and be a risk factor for developing dementia in later life.

Many observational studies have reported that higher blood levels or intake of omega-3 fatty acids are linked to better cognitive function or prevention of dementia. In the Framingham Heart Study, there was a 47 percent decrease in all-cause dementia in the highest quartile of DHA blood levels.1 This group had an average intake of 180 mg DHA per day, similar to the conservative dose I recommend. In the Rancho Bernardo Study of Healthy Aging, a 73 percent reduced risk of dementia was found for both the top third of DHA intake and a 65% reduced risk associated with the top third of DHA blood levels.2 The report from the Framingham Heart Study was partially industry-funded, but recent meta-analyses of all 21 studies on the subject have confirmed the association between DHA and prevention of cognitive decline and dementia.3 DHA and EPA are important components of brain cell membranes, and it is important to have an adequate supply of these fatty acids throughout life to maintain the health of the brain.

Not only do I not say that DHA can improve memory, but I also say that once you are in your eighties or nineties and have shrunk your brain to the point of dementia from long-standing fatty acid deficiency, and experience memory loss – you cannot regrow your brain and repair your dementia with supplements. 

Nelson then criticized me for saying the shrunken brain cannot grow back by presenting a few studies that show that shrinkage of the brain can be slowed with exercise. That, in no way [negates] my assertion that brain shrinkage, to the point of dementia, induced from decades of fatty acid deficiency, cannot be reversed with a supplement used that late point in the disease process.  The point I was making by this statement was that if you let a deficiency exist for decades. By the time you note a problem with memory, it will be too late to resolve it; in other words, we need to prevent it, not attempt to treat it later in life.  

The fact that this 2012 meta-analysis shows DHA supplementation does not improve cognitive function, supports my assertion that you should not wait until after you develop dementia to think you can supplement with DHA to reverse the condition.4 That’s like waiting until you have lung cancer to quit smoking. 

I don’t want those who follow my advice – to eat a vegan diet, or near-vegan diet – to develop any problems due to my guidance. I want to make 100 percent sure nobody is hurt by such advice. I have a responsibility to warn people about the potential risk of DHA deficiency that can happen with a vegan diet. 

Am I lying about having patients and vegan friends and mentors develop severe neurologic problems in later life just so I can make money selling a DHA supplement?

Let’s consider that accusation as well. I have been the primary care physician for over 30 years, caring for over 10,000 families including a broad community of vegans and other plant-based health enthusiasts. I think I may have had more experience with caring for elderly vegans and observing their medical issues than any other living physician.

Think about which other doctor advocating a vegan diet has had this much primary care experience treating elderly vegans – who have developed medical issues in their eighties and nineties. What if you were such a physician and had your patients and their families, who you cared about, suffer such a life-altering difficulty from your dietary advice?  Wouldn’t you do what you could to make sure these problems don’t happen to you, your family, friends, and those who depended on you for advice. Shouldn’t you share your experience to help others here?

Conventional health organizations and conventional physicians, even those specializing in dementia, typically condone eating animal products, including fish.  They have no expertise or experience in caring for elderly, long-term healthy-eating vegans, noting neurological problems and checking their blood work for omega-3 deficiencies. SAD eaters get dementia from their lack of phytonutrients and all the saturated fat and toxic food they consume. Later-life dementia in healthy-eating vegans is a different animal, with an entirely different subset of potential causes, and not an adequately studied phenomenon for them to have a worthwhile opinion on – so their position is meaningless. Especially since they have had no experience with this phenomenon. 

In the 1950s – way before the plant-based movement became popular in America, Dr. Herbert Shelton, the founder of the American Natural Hygiene movement, was promoting a plant-based, largely raw food diet to his avid followers, my father included.

We had a connection with a movement of vegans and near-vegans eating a super healthy, whole foods natural diet for many years. I started going to those Natural Hygiene conferences in the early 1970s and became friendly with the leaders, who mostly have now passed away. Over more than 30 years of my medical career, I have cared for many of these long-term vegans, elderly natural hygienists, and some from the American Vegan Society, who ate extremely healthy, took vitamin B12, and generally lived into their nineties. 

I am mentioning real names of well-known whole food plant-based health leaders to demonstrate these people and their neurologic problems were real.  A significant number of people, including many leaders and doctors in this health movement, developed neurological problems – memory loss and dementia being the most common, like my friend Jerry Deutsch’s mom and Dr. Virginia Vetrano to name a few. But also Parkinson’s Disease, like Dr. Kiki Sidwa and Dr. Herbert Shelton. And my good friend, the famous artist Peter Max, also followed a vegan diet and developed dementia and is still living. When I had the opportunity to check on those patients of mine who had developed these problems, I found the levels of DHA and omega-3 index to be exceptionally low and sometimes even non-existent. Some who are still active in the vegan community do not want me to reveal the names of their parents who developed these same issues. These are not fictional characters, but real people who have suffered greatly. In fact, more of these vegan leaders I knew well, developed neurologic problems than did not.   

Of course, it is well accepted that a whole foods, plant-based diet will reduce heart disease and dementia compared to a standard diet, and that taking fish oils or any type of omega-3 supplement on a standard diet won’t help. There are many more contributory causes of dementia besides low DHA, and I expect most people that have dementia do not have DHA deficiency as a cause.  However, in healthy-eating vegans that changes, because they are doing so many things right, yet still developed these problems. And, if we can easily prevent this with a simple supplement, we should do so. 

In fact, I was motivated to produce a DHA supplement years ago, after observing these problems arising, and there were no vegan DHA-EPA supplements around that did not have high rancidity scores.

Non-supplementing vegans have a broad range of DHA omega-3 index levels: some adequate, many borderline, some marginally deficient, some severely deficient, and some with almost no measurable DHA at all.  And this is well documented, at this point.  Our non-profit research foundation funded a study on 166 non-supplementing vegans to better understand the percentage with very low measurable omega-3, and the results reinforced my clinical findings. The average omega-3 index was 3.7 percent. A significant number – 64 percent – were below 4, and 27 percent were even below 3, and some were even below 2. Only 9 percent had an omega-3 index greater than 5. And these number did not corelate well with ALA intake; that means eating more flax seeds and walnuts did not fix the problem. Genetic differences in conversion enzyme was found to be the most likely critical factor.5 The scientific consensus is that conversion from ALA to EPA and DHA is limited,6 and according to the Office of Dietary Supplements of the National Institutes of Health: “Consuming EPA and DHA directly from foods and/or dietary supplements is the only practical way to increase levels of these fatty acids in the body.”7

The often-touted notion that the VITAL study proved fish oils are not helpful for protection against heart disease is misleading.

When the details of that study were published earlier this year, it showed that when a subgroup of people who ate little or no fish was analyzed, dramatic benefits were observed. In this study, the 25,871 participants either took a fish oil capsule or placebo, and median follow-up time was 5.3 years. Even though overall there was no significant decrease in cardiovascular risk in the omega-3 group, they found this was because those individuals were already eating fish.

In participants who ate less than 1.5 servings of fish per week, there was a 40 percent reduction in heart attack rate in the omega-3 group. And in participants who ate fish less than once per month, there was a 57 percent reduction in heart attack rate, for those supplementing.8

Large doses of fish oil may have negative health effects – almost any type of supplement can cause harm in excess. However, the fact that excess may cause harm has nothing to do with permitting and condoning deficiencies. 

What I would say to those leaders advocating a vegan diet without supplementation is: You’ll gamble with people’s lives and brains and won’t even grant the possibility of low levels increasing risk?

In other words, if you were presented with someone with an omega-3 index below 3, you would not do anything?  Below 2?  This position cannot be defended – and if you are unsure about your convictions, you check labs and err on the side of caution. 

To be absolutely clear, my recommendations,based on a comprehensive review of all the corroborating evidence, is for vegans (and non-fish eaters) to supplement with about 250 mg, which is a low-dose of DHA-EPA – or instead, confirm with a blood test that their omega-3 index is above 5 without supplementation.

Maybe this debate is good, so more people are informed about this critical issue and are not tricked into thinking a low-fat vegan diet without DHA is without risk.

Since the only way to disagree with my findings and the findings of many confirmatory studies is to claim [that] I am lying, and the scientists who run the studies are co-conspirators that have been paid off to fake the results. I don’t care that much about Nelson’s name-calling and trying to smear my character, but the problem is, he is doing that so people won’t believe anything I say, thus the outcome can damage lots of people. Let’s look at the evidence to see who is being honest or dishonest here. 

Here is a sample of some of the claims Nelson has made:

  1. He claimed on his video that I charge $60,000 for a 3-month stay at my health retreat. We charge $36,000 for a private room, that’s $12,000 a month, and lower-priced accommodations are available too. 
  2. He claimed the nut studies showing reduced risk of death from all causes, and a 30-40 percent decrease in risk of cardiovascular death in those eating nuts and seeds daily9 were funded by nut companies, thus invalidating all the evidence. Not true – I posted a list of all the major studies documenting these effects, and both the ones partially funded and those not funded showed the same outcome, to about the same degree, including decreased cancer deaths. And similar results were also found in vegan populations in the Adventist Health Study 2, which he denied.
  3. He claimed I put the Cornell banner behind my name to aggrandize myself and my affiliation with Dr. Campbell in the movie Fat Sick and Neary Dead. He knows this is not true and he has the screen shot to prove that it was a research poster seen on a wall, that had Cornell university under Dr. Campbells name, not with my name.
  4. He gleefully promoted that I put Dr. Campbell’s name first in a published research study and used a bogus document in his video, not the original article, to demonstrate that lie with a screen shot.  He was shown the real article and knows this was a hoax, and that I never did such a thing.
  5. He claimed that I “ghost wrote” the DHA study funded by the Nutritional Research Foundation and faked the results.  Yes, I am the president of this non-profit research foundation, but after recruiting the scientists to conduct this study, I removed myself from having any part in the data collection or write up and had no further collaboration with the scientists or even knowledge of the findings until the scientists finished the study. That was the most ethical thing to do. Of course, he has to claim it is faked by me, because it obliterates his argument if true.
  6. And, in his recent video he claims I have 35 employees in my supplement company. I have several aligned businesses, including a health retreat, a book publishing division, a food division, a medical office and a health company that sells educational materials, foods, healthy condiments and supplements.  Yes, I have 35 employees including chefs, a food scientist, research PhD, and a medical office with nurses, food addiction counselors and doctors. Nelson knows this because I told him. He twisted that to say I have 35 working in a supplement company. 

So, if you believe Nelson and think I am a liar, criminally faking data and paying off scientists to publish false information to promote my DHA supplements, then I will not likely convince you otherwise, though I sincerely wish I could.  I suggest that Nelson is not making careless mistakes, but is intent on destroying my reputation and career.  But there is always the possibility he, too, will be influenced by the evidence and decide to remove all the videos with unfair and incorrect accusations and assertions.    

One thing we know for sure is that being severely deficient in almost any nutrient causes disease.

And excessive amounts cause disease too, by the way.  And I warn against taking high-dose fish oils to drive your omega-3 levels into what may be a high-risk zone. I recommend just a low dose of about 250 mg of total EPA and DHA from an algae-derived supplement. People can overdose with almost any supplement such as vitamin D, iodine, or B6. Too much of certain nutrients can be harmful, but neither should we ignore the problems from deficiencies.   

Is DHA some unique substance that it is impossible to have too little of? Is it possible that a deficiency of this important brain nutrient just does not exist on a vegan diet?  That is what is being claimed here. There are two studies I know of evaluating brain volume with respect to omega-3 index (a measure of red blood cell EPA and DHA levels) and they are both credible, with many reputable scientists involved and these studies were federally funded, not industry funded.

In the first study there was a threshold effect for brain volume, showing a lower brain volume when then the omega-3 index was lower than 3.9%10 The second study showed a linear association: a 3.2% increase in omega-3 index was associated with a 4.2 centimeter cubed increase in total later life brain volume. A much larger brain volume was reported in quartile 4 with a mean omega-3 index of 7.5% compared to quartile 1 with a mean omega-3 index of 3.4%.11 The KORA study is another important study including 720 participants that demonstrated a 77% increase in cognitive impairment with omega-3 index below 5.7%.12

That’s 3 separate studies all corroborating that a lower omega-3 index is associated with smaller brain volumes or cognitive decline.  We can’t say exactly what the ideal omega-3 index would be, but 5 seems a reasonable goal, but clearly it is risky to have a omega-3 index below 4, and that is where about 60 percent of non-supplementing vegans were on the study funded by the Nutritional Research Foundation noted above.13   Only 9 percent of non-supplementing vegans tested in this study had blood levels above 5, which is likely the safest place to be. 

Let’s go on to the idea that taking a low-dose DHA supplement can cause prostate cancer and that is why we must avoid this, according to Nelson.

This study appears to be how he first convinced Dr. Klaper to stop taking or recommending DHA.  First of all, the study in question did not look at DHA intake, fish intake or algae DHA supplement intake.  They only looked at plasma phospholipid levels of omega-3, not the standard acceptable research test. An omega-3 index, because it is a measure taken from red blood cells, is more accurate and reflective of longer-term DHA status.14

Nevertheless, the two blood samples used were not drawn decades before and do not reflect years of omega-3 levels or intake, just likely how much fish they were eating in the days or weeks before their blood was drawn.

Keep in your mind that the major finding in this same study was that low levels of trans fat were associated with more cancer, and the lowest levels were found with more aggressive cancer.15  Trans fat, as you might have heard, is outlawed; it is the most dangerous fat a person can eat, yet this study showed higher amounts in the blood was protective against aggressive prostate cancer. If the results of this study are to be taken seriously, we should be eating margarine and Crisco oil to protect ourselves from prostate cancer.

Remember, cancer causes accumulate for decades before diagnosis. The researchers only had two blood draws, and only the first was drawn before the men knew they had cancer. The second one, drawn a few years later, may have included men who found out they had cancer or had at least noted a rising PSA, so they could have modified their diet as a result.

All we know from this study is that men with more advanced or aggressive prostate cancer ate more fish. Men noting a rising pre-cancerous PSA or prostate cancer typically try to eat healthier, with less meat and more fish. So we don’t really know the significance of this trivial finding that found a very slightly higher plasma omega-3 level in this group with more aggressive cancer. It may be from high fish intake causing a problem, or it may just reflect the timing of the second blood draw. Nevertheless, it has nothing to do with vegans using a small dose of DHA to prevent deficiency.

These results can only make sense if some were informed that they were at heightened risk and then started to eat better, with less trans-fat and less junk food and started to eat more fish instead of red meat. The fact that trans fats were so low in those with aggressive cancer indicates that some men who developed these cancers likely were aware they had some problem brewing. There is no way higher levels of dangerous man-made trans fats could be protecting against prostate cancer, so we know these findings must be a red herring.  If we think the findings from this study indicates DHA causes cancer then we should be eating margarine and more potato chips and fried fast food to protect against prostate cancer.  Obviously, the findings in this study are meaningless. 

Prostate cancer is a slowly growing disease taking decades to manifest and advance to those advanced stages.

If this study reflected an actual effect of omega-3 fatty acids, we would see more prostate cancer in Japan where they eat so much fish throughout life, taking in eight times the amount of fish oils compared to Americans and their DHA levels are double the levels compared to the US. But they have less than a third of the prostate cancer we see here.

If we are considering something so surprising and unlikely that even a low dose of DHA would cause prostate cancer, at least the person presenting that position should review all the studies looking at this question and see where the totality of the evidence points.

A fundamental aspect of quality research is consistency and repeatability.

Reputable studies looking at this question show the opposite: They show higher DHA levels are associated with lower risk of prostate cancer.  A recent meta-analysis of fish and prostate cancer showed fish had a protective effect on prostate cancer mortality.16  There are many studies, and the results have not been consistent.17 There are some theories about possible reasons for the increases in risk seen in a few of the studies. It could be the accumulated heavy metals or other pollutants in fish.18  And very high doses of EPA and DHA from fish oil can have an immunosuppressive effect.19 There is also the possibility of detection bias, where health-conscious men are more likely to eat fish or take fish oil and have PSA screening, making a diagnosis of prostate cancer more likely.20

My advice for those eating plant-rich diets has always been to avoid high-dose fish oil supplements and instead take a small dose of vegan EPA-DHA instead. The fact that there may be some small potential risk from high-dose fish oil or from eating lots of fish, has no bearing on the recommendation for non-fish-eaters to take a small insurance dose of algae-derived EPA and DHA to prevent insufficiency and protect brain health with aging.

Dr. Ornish showed his nutritional program reversed prostate cancer – and his program included 3 grams of fish oil supplement a day. The idea that a well-designed vegan diet with just a low dose algae supplement (250 mg) to avoid a deficiency in DHA would cause prostate cancer is not only unsupported, but ludicrous. And, mentioning Dr. Ornish – his recent review of much of this science had him change his prior advice, and now he recommends not only DHA, but also that his heart patients and others consume some nuts and seeds in their diet. 

Of course, all of you are free to have your own conclusions and beliefs without being attacked.  

Nelson’s attacks on Dr. Greger are also without substance; they are false and devious.

He suggested that I am funding Dr. Greger’s salary or work, so that would make him beholden to me to promote DHA.  I think it was about 6 years ago when Dr. Greger was first starting up Nutrition Facts, I donated $1000 to help his website get started.  Many thousands have donated money to help Dr. Greger’s noble work, and that wide base of support removes conflict of interest and does not create them.  And many scientists serve as advisors for our non-profit research studies, none of them are paid anything. They exist so we can get their opinion on studies to financially support. A smear campaign attacking Dr. Greger is beyond belief, considering Dr. Greger’s authenticity, dedication and being so independent of influence, and being so helpful to many thousands of people.  I guess Greger’s major crime (according to Nelson) is agreeing with me. The facts are we both review the science carefully ­– and have no predetermined agendas to protect.

The profits in my business are not dependent on DHA sales and selling more DHA is not my agenda. Protecting people is my agenda.   

Yes, I am saying that Nelson and the very low-fat plant-based colleagues who exclude nuts and seeds, or only allow trivial amounts without DHA, are placing some people at needless increased risk. That does not mean that these individuals have not helped lots of people too, by getting them off their oils, meats and junk food. But I don’t take needless risk lightly, and I am not going to take a chance with the people depending on my advice to even have a small chance of being damaged from such low-fat extremism.

I’m sure this won’t stop them and their loyal followers from denying the preponderance of evidence here. But at least you now know important information to an informed decision about your health. And maybe some of these doctor-gurus will actually be influenced to modify their recommendations with all this hard-to-deny evidence. 

What is so ironic is that there is a false concern about a tiny dose of DHA to protect the brain being prostate cancer-causing, when there is irrefutable evidence from numerous corroborating studies showing that diets omitting nuts and seeds and eating so little fat dramatically increase both cardiovascular death and cancer deaths, but that does not seem to be a concern to these low-fat extremists.  Correct science always prevails in the long run, as more evidence accumulates. 

Wishing you all great health and much happiness.

  1. Schaefer EJ, Bongard V, Beiser AS, et al. Plasma phosphatidylcholine docosahexaenoic acid content and risk of dementia and Alzheimer disease: the Framingham Heart Study. Arch Neurol. 2006;63(11):1545-1550.

  2. Lopez LB, Kritz-Silverstein D, Barrett Connor E. High dietary and plasma levels of the omega-3 fatty acid docosahexaenoic acid are associated with decreased dementia risk: the Rancho Bernardo study. J Nutr Health Aging. 2011;15(1):25-31.

  3. Zhang Y, Chen J, Qiu J, Li Y, Wang J, Jiao J. Intakes of fish and polyunsaturated fatty acids and mild-to-severe cognitive impairment risks: a dose-response meta-analysis of 21 cohort studies. Am J Clin Nutr. 2016;103(2):330-340. Yurko-Mauro K, Alexander DD, Van Elswyk ME. Docosahexaenoic acid and adult memory: a systematic review and meta-analysis. PloS one. 2015;10(3):e0120391.

  4. Sydynham E, et al. Omega 3 fatty acid for the prevention of cognitive decline and dementia. Cochrane Database syst Rev 2012 Jun 13;(6):CD005379.

  5. Sarter B, Kelsey KS, Schwartz TA, Harris WS. Blood docosahexaenoic acid and eicosapentaenoic acid in vegans: Associations with age and gender and effects of an algal-derived omega-3 fatty acid supplement. Clin Nutr. 2015;34(2):212-8.

  6. Arterburn LM, Hall EB, Oken H. Distribution, interconversion, and dose response of n-3 fatty acids in humans. Am J Clin Nutr 2006;83:1467S-1476S. Davis BC, Kris-Etherton PM. Achieving optimal essential fatty acid status in vegetarians: current knowledge and practical implications. Am J Clin Nutr 2003;78:640S-646S.

  7. Office of Dietary Supplements, National Institutes of Health. Omega-3 Fatty Acids. Fact Sheet for Health Professionals. .

  8. Manson JE, Cook NR, Lee IM, Christen W, Bassuk SS, Mora S, Gibson H, Albert CM, Gordon D, Copeland T, et al. Marine n-3 Fatty Acids and Prevention of Cardiovascular Disease and Cancer. N Engl J Med 2019, 380:23-32.

  9. Grosso G, Yang J, Marventano S, Micek A, Galvano F, Kales SN. Nut consumption on all-cause, cardiovascular, and cancer mortality risk: a systematic review and meta-analysis of epidemiologic studies. American J Clin Nutr. 2015;101(4):783-793.

    Mayhew AJ, de Souza RJ, Meyre D, Anand SS, Mente A. A systematic review and meta-analysis of nut consumption and incident risk of CVD and all-cause mortality. Br J Nutr. 2016;115(2):212-225.

  10. Tan ZS, et al. Red blood cell omega-3 fatty acid levels and markers of accelerated brain aging. Neurology. 2012;78(9):658–664. 

  11. Potalla JV, et al. Higher RBC EPA + DHA corresponds with larger total brain and hippocampal volumes. WHIMS-MRI Study. Neurology 2014;82(5):435–442.

  12. Lukaschek K, von Schacky C, Kruse J, Ladwig KH. Cognitive Impairment Is Associated with a Low Omega-3 Index in the Elderly: Results from the KORA-Age Study. Dement Geriatr Cogn Disord. 2016;42(3-4):236-245.

  13. Sarter B, Kelsey KS, Schwartz TA, Harris WS. Blood docosahexaenoic acid and eicosapentaenoic acid in vegans: Associations with age and gender and effects of an algal-derived omega-3 fatty acid supplement. Clin Nutr. 2015;34(2):212-8.

  14. Sun Q, Ma J, Campos H, et al: Comparison between plasma and erythrocyte fatty acid content as biomarkers of fatty acid intake in US women. Am J Clin Nutr 2007;86:74-81.

  15. Brasky TM, Darke AK, Song X, et al. Plasma Phospholipid Fatty Acids and Prostate Cancer Risk in the SELECT Trial. J Natl Cancer Inst 2013.

  16. Szymanski KM, et al. Fish Consumption and prostate cancer risk: a review and meta-analysis. Am J Clin Nutr 2010;92(5):1223-1233.

  17. Aucoin M, Cooley K, Knee C, Fritz H, Balneaves LG, Breau R, Fergusson D, Skidmore B, Wong R, Seely D. Fish-Derived Omega-3 Fatty Acids and Prostate Cancer: A Systematic Review. Integr Cancer Ther 2017, 16:32-62. Dinwiddie MT, Terry PD, Whelan J, Patzer RE. Omega-3 Fatty Acid Consumption and Prostate Cancer: A Review of Exposure Measures and Results of Epidemiological Studies. J Am Coll Nutr. 2016;35(5):452-468. Fu YQ, Zheng JS, Yang B, Li D. Effect of individual omega-3 fatty acids on the risk of prostate cancer: a systematic review and dose-response meta-analysis of prospective cohort studies. J Epidemiol 2015, 25:261-274. Crowe FL, Appleby PN, Travis RC, et al. Circulating fatty acids and prostate cancer risk: individual participant meta-analysis of prospective studies. Journal of the National Cancer Institute. 2014;106(9).

  18. Fu YQ, Zheng JS, Yang B, Li D. Effect of individual omega-3 fatty acids on the risk of prostate cancer: a systematic review and dose-response meta-analysis of prospective cohort studies. J Epidemiol. 2015;25(4):261-274.

  19. Office of Dietary Supplements, National Institutes of Health. Omega-3 Fatty Acids. Fact Sheet for Health Professionals.

  20. Fu YQ, Zheng JS, Yang B, Li D. Effect of individual omega-3 fatty acids on the risk of prostate cancer: a systematic review and dose-response meta-analysis of prospective cohort studies. J Epidemiol 2015, 25:261-274. Crowe FL, Appleby PN, Travis RC, et al. Circulating fatty acids and prostate cancer risk: individual participant meta-analysis of prospective studies. Journal of the National Cancer Institute. 2014;106(9).


Joel Fuhrman, M.D. is a board-certified family physician, seven-time New York Times bestselling author and internationally recognized expert on nutrition and natural healing, who specializes in preventing and reversing disease through nutritional methods. Dr. Fuhrman coined the term “Nutritarian” to describe his longevity-promoting, nutrient dense, plant-rich eating style.
For over 30 years, Dr. Fuhrman has shown that it is possible to achieve sustainable weight loss and reverse heart disease, diabetes and many other illnesses using smart nutrition. In his medical practice, and through his books and PBS television specials, he continues to bring this life-saving message to hundreds of thousands of people around the world.


Comments (0):


Ron Weiss, MD

12/21/2019 03:28 PM

For years in my primary care practice we have been monitoring omega 3 indexes and have noted a good number of plant-based individuals who eat flax seed, nuts and seeds, and are still deficient. I agree that in the face of this deficiency, at this time, given the available data, it is most reasonable to supplement with algae sourced DHA/EPA to avoid an apparent higher risk of dementia later in life. 

Ron Weiss, MD
Ethos Primary Care


12/25/2019 03:23 PM

Is there a link to Dr. Klaper's retraction of the statements featured on Jeff Nelson’s video, as mentioned in the 3rd paragraph (after the "Note")?  Thanks.

Dr. Fuhrman

01/02/2020 10:48 PM

He said he was going to post it shortly--I will find out. 


02/03/2020 03:40 PM

Since Dr Klappers post I stopped taking an Algae oil DHA Suppliment as I concluded the risks of Developing Prostate cancer were significant. Having now read all the information I can find on this subject to date, including Dr Klapper's original post and this very well worded explanation, I am concluding that any link between Prostate Cancer and Algae oil/DHA Suppliments is in effect unproven and therefore it is relatively safe to take a low dosage (500mg Algae Oil 250mg DHA / Day esp. given the upside benefit(s). I'm assuming this is what Dr Klaper will in effect be posting on his web site in due course. Is this a fair assumption do you think ? 

This comment was last edited on 02/03/2020 04:02 PM

Dr. Fuhrman

02/04/2020 09:48 AM

I did communicate with Dr. Klaper about a week ago, and he did still say he was still going to come out with a video shortly to correct his prior one.  I am not certain what is holding him up, but I know he has been intimidated by Nelson.  I think he is worried about having his character attacked and being slandered publically, as I and others have for telling the truth.  

Dr. Fuhrman

02/10/2020 01:17 PM

Dr. Klaper recently posted another YouTube video on this subject. But shockingly he only has it on Nelson’s channel, that means, I cannot comment there (Nelson blocks me and my staff and hides any disenting comments).  So that means that Dr. Klaper is allowing Jeff Nelson to control the narrative on this issue and is not open to letting others hear an opposing view. He has joined forces with Nelson in disseminating their brand of radical veganism mixed in with hate for those with opposing viewpoints and character assasination. 


What is also strange and alarming is that during the last few months Dr. Klaper communicated to me an entirely different view compared to what he finally came up with and posted on Nelson’s site. I am surprised by his recent message as it is not science based. In other words, he could not point to studies to back up his speculative fears and assertions because there are none, and he ignored the numerous studies that conclusively document brain shrinkage and cognitive impairment occurs from a low omega-3 index. 


Here are 4 studies that clearly document brain damage from low omega-3 index: 


Tan ZS, et al. Red blood cell omega-3 fatty acid levels and markers of accelerated brain aging. Neurology. 2012;78(9):658–664. This study found reduced brain volume in older adults with an omega-3 index lower than 3.9 percent[1] Potalla JV, et al. Higher RBC EPA + DHA corresponds with larger total brain and hippocampal volumes. WHIMS-MRI Study. Neurology 2014;82(5):435–442. In this study of older women, a 3.2 percent increase in omega-3 index was associated with a 4.2 cm3 increase in total brain volume 8 years later. Greater omega-3 index also correlated with larger volume of the hippocampus, a region of the brain associated with memory. [2] Lukaschek K, von Schacky C, Kruse J, Ladwig KH. Cognitive Impairment Is Associated with a Low Omega-3 Index in the Elderly: Results from the KORA-Age Study. Dement Geriatr Cogn Disord. 2016;42(3-4):236-245. This study found a 77 percent increase in cognitive impairment in participants with an omega-3 index below 5.7 percent.[3] Coley N, Raman R, Donohue MC, et al. Defining the Optimal Target Population for Trials of Polyunsaturated Fatty Acid Supplementation Using the Erythrocyte Omega-3 Index: A Step Towards Personalized Prevention of Cognitive Decline?. J Nutr Health Aging. 2018;22(8):982–998. In this trial of omega-3 supplementation, analysis of the placebo group showed that those in the bottom fourth of omega-3 index (below 4.83 percent) had more cognitive decline over three years than the rest of the participants.[4]


Do vegans have some unique physiology that make them immune to brain shrinkage from DHA deficiencies?  I already presented the well-known vegans I knew and some that I cared for, who followed a Natural Hygiene or healthy vegan diet, and still developed dementia or Parkinson’s. I named names and explained my unique experience in caring for this community, where many well-known, leaders in this community developed later life brain problems, yet Dr. Klaper has chosen to ignore this.  Remember, no primitive society ever lived on a vegan diet, they all had some EPA-DHA in their diet from animal products. A vegan diet with no DHA-EPA exposure is an experiment in human history with unknown consequences.


Let me say this as clearly and as strongly as I can: There is zero evidence that eating or ingesting DHA or EPA in any form, in the small amount recommended, could cause EPA levels to rise in cells and cause harm. Not only is that not shown to happen in any study, but it is not even a logical hypothesis.  When your body has a low omega-3 index and is starving for omega-3, it cannot build up high in tissues.  It can’t build up in tissues and be deficient in tissues at the same time. 


Klaper cites this paper and claims it indicates potential harm from taking a DHA supplement.  His assertion is ridiculous as no such evidence in this study he presents supports his position. 


Metherel AH, Irfan M, Klingel SL, et al. Compound-specific isotope analysis reveals no retroconversion of DHA to EPA but substantial conversion of EPA to DHA following supplementation: a randomized control trial. Am J Clin Nutr. 2019;110(4):823-831. 


In this study, participants supplemented with 3g/d DHA, 3g/d EPA, or a control supplement (olive oil) for 12 weeks. It does make sense that taking such huge amounts of supplemental DHA supplementation would lead to more plasma EPA and a slowing of EPA metabolism, as the body does not need to make more DHA from EPA. 


There is no indication or discussion in this paper of any potential negative effect of this increased EPA. This study used 3 g/day DHA, which is 17 times what we recommend and have in our supplement, so that says nothing about using a small dose to prevent deficiency.  Besides there is no evidence of negative effects of higher circulating EPA: higher circulating EPA has been associated with reduced risk of all-cause mortality, cardiovascular mortality, coronary heart disease, and  cardiovascular events.[5]


As we know, very high daily doses of fish oil have been associated with suppression of immune function: higher than 900 mg/day EPA + 600 mg/day DHA for several weeks. Also, doses above 2 g/day might increase bleeding time.[6] Again, these are much higher doses than what we recommend (for healthy people) and like with all other nutrients, both too little and too much may be harmful.  In conclusion, this study does not support any of Dr. Klaper’s fabricated fears or concerns. 


And not only is it false information to claim that higher (adequate) levels of DHA and EPA increase exposure to toxins and inflammation, but the exact opposite is true.  It is low levels of these omega-3 fatty acids that increase inflammation and susceptibility to toxins.[7]  In fact, the mechanism via which deficiencies in EPA-DHA likely increase risk of Parkinson’s is likely by increasing the susceptibility of brain cells to the chemicals that cause Parkinson’s.[8]  


Dr. Klaper references a few studies to incorrectly claim that DHA effects on intestinal epithelial barrier function could increase permeability to toxins/carcinogens.  In fact a review of those studies and others explaining the role of DHA in cell membranes demonstrate the opposite.  When treated intestinal epithelial cells or animals with DHA plus a pro-inflammatory stimulus or heat stress found that DHA or EPA prevented the increase in permeability that the inflammatory stimulus/stress alone caused.[9] Similarly, intestinal epithelial monolayers treated with DHA/EPA plus a toxin (cyclosporin A – DHA or deoxynivalenol – DHA and EPA), the omega-3 fatty acids blocked inhibited the increase in permeability due to the toxin.[10] DHA has also been found to protect barrier integrity in brain endothelial cells and reduce toxicity in brain endothelial cells, pericytes, and glial cells following treatment with amyloid-beta.[11]  So his concern about DHA increasing intestinal membrane permeability or susceptabilit to toxins is unfounded and incorrect.


Certainly, I am disappointed in Dr. Klaper, and I think anyone who would allow even some people to potentially suffer with later life dementia as a result of their nutritional advice is irresponsible, especially since there is no evidence to  demonstrate harm from this valuable preventive measure. In other words, he expressed irrational fears with no scientific support for them. Where are the referenced scientific papers that support his concerns from taking a small dose of DHA-EPA?  None! Furthermore, from my three decades of practicing medicine, I have had the most experience caring for this long-term vegan population and have witnessed the development of dementia or Parkinson’s with a concomitant low level of DHA-EPA over and over again.


Interestingly, I even told Dr. Klaper about another couple who both became demented after they followed the lead of my father to follow a natural whole foods vegan diet about 40 years ago.  An unscrupulous person “stole” their house from them, convincing them to sell at a very low price and I had to vouch for their dementia with a judge to get their home back. 


Dr. Klaper’s assertion that DHA deficiency is not a generally recognized cause of dementia in the general population is irrelevant. I have already addressed the fact that most dementia in the general population is caused by lack of vegetables (anti-oxidants), not lack of DHA.  These so-called experts are not experts in plant-based nutrition and are not studying the unique causative pattern in healthly-eating vegan populations who still get dementia.  And, we already have conclusive data showing that non-fish eaters and low omega-3 index causes brain shrinkage and cognitive impairment (or dementia).


If the liver could make all we need, we would not see such a high percentage of vegans with a very low omega-3 index; this is also well established.[12]  It is also irrelevant if high ALA intake would aid in raising the index in some people, because if you are one of those who can get your body to get an index above 5 or 6 via nutritional gymnastics, then great, it is unnecessary for you to take DHA.  But if you, like most of us, can’t get your omega-3 index above 5 or 6 with a great diet, then it would be very foolish to not take a DHA-EPA supplement.  Dr. Klaper’s experiment on himself is irrelevant. Why would it matter if his index is good or not good in 6 months; we are all not the same.  If his number turns out to be above 6, that does not mean yours will. 


If these omega-3 index tests were almost useless, as Dr. Klaper seems to believe, then we would not see consistency among studies showing low levels associated with brain shrinkage. Then we would see no correlation between low levels and brain disease.  The facts are the exact opposite of what Dr. Klaper asserts. 


Also just because synthetic folic acid, beta carotene and vitamin A are harmful, and best ingested via plants in a complex form, that does not make all supplements dangerous. That is irrational to use that information to make the argument that all supplements therefore are harmful. Is B12 harmful if you are B12 deficient?  Is Vitamin D harmful in vitamin D deficiency, is zinc or iodine harmful in deficient individuals whose dietary exposure is lacking?  Is DHA-EPA from a supplement harmful when hundreds of studies show benefits to the brain from it?  And, there never been a shred of evidence to the contrary.


It also is anti-science to claim that DHA supplementation is associated with prostate cancer. Dr Klaper ignored all the studies that one would need to review to make that claim.  In my previous posts and videos, I addressed the falsity of that claim.  For Dr. Klaper to mention that here when that claim has already been shown to be false is demonstrative of something fishy.  I would think he would be aware of the many studies showing DHA-EPA is protective against all cancers, including those of the prostate.  


We have to go with science and facts—we have to err on the side of caution and not what could potentially damage people’s brains.  Unfortunately, I not only disagree strongly, but I sincerely hope vegans choose to adhere to the science and not these invented fears without scientific support. I have always liked and respected Dr. Klaper, but I’m afraid that there is some undisclosed reason for his twisting the science here and trust my experience working with this community. There are intimidating people on the internet and it takes courage to disagree with them. Fortunately, I am but one of many doctors in the plant-based community and lifestyle medicine community that agree and support this cautionary approach. 


Besides my video here, if you want to read the transcript and my other detailed blog posts on this issue go to.

[1] Tan ZS, et al. Red blood cell omega-3 fatty acid levels and markers of accelerated brain aging

 Neurology. 2012;78(9):658–664. 

[2] Potalla JV, et al. Higher RBC EPA + DHA corresponds with larger total brain and hippocampal volumes. WHIMS-MRI Study. Neurology 2014;82(5):435–442.

[3] Lukaschek K, von Schacky C, Kruse J, Ladwig KH. Cognitive Impairment Is Associated with a Low Omega-3 Index in the Elderly: Results from the KORA-Age Study. Dement Geriatr Cogn Disord. 2016;42(3-4):236-245.

[4] Coley N, Raman R, Donohue MC, et al. Defining the Optimal Target Population for Trials of Polyunsaturated Fatty Acid Supplementation Using the Erythrocyte Omega-3 Index: A Step Towards Personalized Prevention of Cognitive Decline? J Nutr Health Aging. 2018;22(8):982-998.

[5] Harris WS, Luo J, Pottala JV, Espeland MA, Margolis KL, Manson JE, Wang L, Brasky TM, Robinson JG. Red blood cell polyunsaturated fatty acids and mortality in the Women's Health Initiative Memory Study. J Clin Lipidol 2017, 11:250-259 e255. Miura K, Hughes MCB, Ungerer JP, Green AC. Plasma eicosapentaenoic acid is negatively associated with all-cause mortality among men and women in a population-based prospective study. Nutr Res 2016, 36:1202-1209. Mozaffarian D, Lemaitre RN, King IB, Song X, Huang H, Sacks FM, Rimm EB, Wang M, Siscovick DS. Plasma phospholipid long-chain omega-3 fatty acids and total and cause-specific mortality in older adults: a cohort study. Ann Intern Med 2013, 158:515-525.

[6] Office of Dietary Supplements, National Institutes of Health. Omega-3 Fatty Acids. Fact Sheet for Health Professionals []

[7] Calder PC. Omega-3 Fatty Acids and Inflammatory Processes. Nutrients 2010 Mar;2(3): 355–374. 

[8] Bousquet M, Saint-Pierre M, Julien C, Salem N Jr, Cicchetti F, Calon F. Beneficial effects of dietary omega-3 polyunsaturated fatty acid on toxin-induced neuronal degeneration in an animal model of Parkinson's disease. FASEB J. 2008;22(4):1213–1225.

[9] Xiao G, Tang L, Yuan F, Zhu W, Zhang S, Liu Z, Geng Y, Qiu X, Zhang Y, Su L. Eicosapentaenoic acid enhances heat stress-impaired intestinal epithelial barrier function in Caco-2 cells. PLoS One 2013, 8:e73571. Li Q, Zhang Q, Wang M, Zhao S, Xu G, Li J. n-3 polyunsaturated fatty acids prevent disruption of epithelial barrier function induced by proinflammatory cytokines. Mol Immunol 2008, 45:1356-1365. Zhao J, Shi P, Sun Y, Sun J, Dong JN, Wang HG, Zuo LG, Gong JF, Li Y, Gu LL, et al. DHA protects against experimental colitis in IL-10-deficient mice associated with the modulation of intestinal epithelial barrier function. Br J Nutr 2015, 114:181-188. Beguin P, Errachid A, Larondelle Y, Schneider YJ. Effect of polyunsaturated fatty acids on tight junctions in a model of the human intestinal epithelium under normal and inflammatory conditions. Food Funct 2013, 4:923-931.

[10] Thakkar RR, Wang OL, Zerouga M, Stillwell W, Haq A, Kissling R, Pierce WM, Smith NB, Miller FN, Ehringer WD. Docosahexaenoic acid reverses cyclosporin A-induced changes in membrane structure and function. Biochim Biophys Acta 2000, 1474:183-195.                  Xiao K, Liu C, Qin Q, Zhang Y, Wang X, Zhang J, Odle J, Lin X, Hu CA, Liu Y. EPA and DHA attenuate deoxynivalenol-induced intestinal porcine epithelial cell injury and protect barrier function integrity by inhibiting necroptosis signaling pathway. FASEB J 2020, 34:2483-2496. Veszelka S, Toth AE, Walter FR, Datki Z, Mozes E, Fulop L, Bozso Z, Hellinger E, Vastag M, Orsolits

[11] Veszelka S, Toth AE, Walter FR, Datki Z, Mozes E, Fulop L, Bozso Z, Hellinger E, Vastag M, Orsolits B, et al. Docosahexaenoic acid reduces amyloid-beta induced toxicity in cells of the neurovascular unit. J Alzheimers Dis 2013, 36:487-501.

[12] Sarter B, Kelsey KS, Schwartz TA, Harris WS. Blood docosahexaenoic acid and eicosapentaenoic acid in vegans: Associations with age and gender and effects of an algal-derived omega-3 fatty acid supplement. Clin Nutr. 2015;34(2):212-8. Sanders TA. DHA status of vegetarians. Prostaglandins Leukot Essent Fatty Acids 2009, 81:137-141. Davis BC, Kris-Etherton PM. Achieving optimal essential fatty acid status in vegetarians: current knowledge and practical implications. Am J Clin Nutr 2003;78:640S-646S.


This comment was last edited on 02/14/2020 01:21 PM


03/19/2020 08:31 AM

Dr. F - I find it infuriating that you need to spend your valuable time combating this. Your time is better spent helping those of us who need your expertise and yes, your products! 


08/12/2020 03:37 PM

The topic came up today in the comments on  To me, whenever it comes up, the fact that Dr. Ornish succeeded at reversing prostate cancer and he has patients taking Omega 3 supplements is enough for me.

Dr. Fuhrman

08/12/2020 07:50 PM

Is in indeed sad that some people are following a small voice in the plant-based world that are denying the reality that DHA deficieny is real and can damage and shrink your brain.  My hope is for all to be safe.  It reminds me of the denial of climate change and that humans are unable to band together to fight a unified war against destruction of the earth.   

This comment was last edited on 08/13/2020 02:27 PM


08/28/2020 12:15 PM

I appreciate this more than you can possibly know. I have been plant-based for 13 years since I read Eat to Live. (My husband has been pretty much plant based since a stay at True North a few years ago, but has gotten serious about it since March.) However, I listened to a Santa Rosa plant based doc's talk about fat vegans and nuts. As a woman with a lifelong eating disorder, I jumped into the "stay skinny with no nuts" pool without looking. I feel ok, but have never gained the vibrant health I desired. I developed PMR and still suffer from chest pain and nausea most of the time. I consulted another famous plant doc in Cleveland, who further insisted no nuts was the right thing to do. I am slim and fit, but super depressed. I fight the depression with exercise, positive mental attitude, prayer, meditation, and the most excellent nutrition I can get, but it is always there. I listened to Jeff's first couple of videos on this before blocking him from my YT and FB feeds. Negativity fuels depression. Anyway, I felt impressed by God to re-read Eat To Live the other day, which led me to your newest book Eat For Life. Then I looked up your talks on YT and came to this video. Wow! This is the missing piece. It's kind of infuriating that it was my original piece, and I somehow let myself be talked out of it. Finally, I took care of both my in-laws through dementia (and cancer) and really don't want to go there. I ordered DHA tests for both my husband and I as well as the sup. Dementia is way more difficult to deal with than cancer. If hubby gets prostate cancer from the sup, so be it. We don't want dementia. Thank you, so much.


Dr. Fuhrman replies:

08/29/2020 05:18 PM

The idea that a low dose DHA-EPA supplemnt would increase risk of prostate cancer is absurd and without scientific support. For depressun high dose EPA, tryptophan, saffron, Same, and others can be extremely helpful.   OUr Mood Biotect may be helpful for you.  

Come into the member center Ask The Doctor so we can discuss further and offer further help if needed. 


11/30/2020 03:13 AM

Oh my a 30 minute post I typed on my phone  got wiped out on the save. :-(


My journey, MCI, diverticulitis, memory issues, and a recent decision to 'supplement" with meat and eggs after being WFPB for about 5 to 10 years (80 to 85 meals out of 90 per month)  

The spatial imagination loss, memory and name recall, project frustration (almost ADHD like?) Maybe chronic dehydration?

My favorite mem/quote is "I dont mind dying, I just dont want it to be my fault."  Dr. Kim somebody. 

I feel like this road and maybe my alcohol issues (4.5 years sober) and maybe the stress of the stress of memory concerns, maybe be NOT good for me.  and my brain and hippocampus is suffering or deteriorating. My wife says I am and "ask-hole" but after all the Greger, Essylstyn, mr and mrs Klapper, Fuhrman and McDougal and etc.  . Is it my fault and my interpretation or path??   

Need a sherpa/guide I cant guess wrong.

Thomas Lynch  [email protected]