As a Yiddish speaker might say with a sigh, “oy, vey”.
An episode of the widely watched Dr. Oz show drew that exclamation of exasperation from us … and a top scientist we contacted for comments.
We just came across the archived video of his March 8, 2013 show, titled “The Man Who Says You Can Prevent Alzheimers”.
His heart may be in the right place … but his passion for the vegan lifestyle has misled his head.
When Dr. Oz asked whether he would recommend that his viewers stop eating fish, Dr. Barnard replied “Yes, absolutely …”
As renowned brain researcher Michael Crawford, PhD, of Imperial College, London told us, “What that fellow says is based on monumental ignorance.”
Oz Show allowed bogus advice ... unchallenged
The Dr. Oz show has conveyed plenty of good health information over the years.
But one horribly misleading episode on brain health featured Dr. Neal Barnard of PCRM.
We felt a responsibility to respond in our newsletter, because the show continues to circulate via the Dr. Oz Show video archive.
He asked Dr. Barnard to describe the diet he recommends to help prevent Alzheimer's and other forms of dementia or brain decline.
As Dr. Oz said in his introduction, Dr. Barnard's approach “has been called radical” … because it requires a vegan diet, free of all meat, fish, and dairy products.
Our rebuttal to Dr. Bernard's fishy claims and advice
We've posted responses to Dr. Barnard's assertions below, and inserted comments we requested from an internationally respected brain expert.
We're most appalled by his utter rejection of seafood, but our rebuttal starts with his fundamental claim that dietary metals and saturated fats cause Alzheimer's disease ... which, he explains, is why everyone should avoid meat, fish, and dairy.
Dr. Barnard focused blame for Alzheimer's on three metals – iron, copper, and zinc.
These metals – especially copper – are often found at higher than average levels in the amyloid beta plaque seen in all Alzheimer's patients' brains.
In turn, he claimed, excesses of iron, copper oxidize cellular fats and generate damaging free radicals.
Metals do drive oxidation and play a mysterious role in the accumulation of plaque in the brain.
And most – but not all – research finds higher-than-average levels of metals in Alzheimer's patients' brains (Park JH et al. 2013).
Alzheimer's patients' brains also show higher-than-average levels of free radicals … which also result from the excesses of starch, sugar, and omega-6 plant fats in the standard American diet.
It is not clear whether higher brain levels of iron, copper, and zinc are a cause of the disease process or a side effect of either the disease process or of genetic factors known to promote Alzheimer's powerfully.
Nor do we know whether the relatively high concentrations in Alzheimer's patients' brain cause or result from the still-unknown factors (some genetic) that promote the disease.
Also – as with the unclear role of metals – it's not clear whether the plaque in Alzheimer's patients' brains causes or results from the Alzheimer's process.
The higher brain levels of iron, copper, and zinc seen in many Alzheimer's patients' brains come from cookware, supplements, meat, and fish.
The published biomedical research holds little or no evidence the higher brain levels of iron, copper, and zinc seen in many Alzheimer's patients' brains result from any of the animal or plant foods in patients' diets.
A similar claim arose in the 1980's when it was found that Alzheimer's patients' brains tend to have more aluminum than average.
Since then, it's become quite clear that Alzheimer's patients accumulate more aluminum in their brains, versus their healthy peers. In other words, high aluminum levels are a side effect of the disease, not its cause.
And if dietary copper promotes Alzheimer's, then you should avoid the plant foods Dr. Barnard recommends to replace meat and fish.
With the exception of shrimp, all of the best sources of copper – ranked by the amount per normal serving size for each food – are plant foods.
The USDA's “very good or excellent” copper sources include many nuts, whole grains, seeds, and beans, turnip greens, asparagus, crimini mushrooms, and tempeh (a soy-based food recommended to vegans as a source of protein and vitamin B12).
Likewise, the top zinc sources per normal serving size include nuts and seeds as well as beef, lamb, and shellfish … but not fish.
Finally, the richest iron sources are all plant foods, with many containing more than 10 percent of a daily iron requirement per serving.
Some, such as lentils and spinach, contain as much as a third of the daily requirement. Legumes and leafy green vegetables rank among the best sources, and whole grains have significant amounts of iron.
Dr. Barnard damns meat and dairy for their saturated fat – higher intakes of which are indeed linked to higher risk for Alzheimer's and other forms of dementia or brain decline.
It's true that diets high in saturated fat are linked to increased risk for Alzheimer's and dementia.
But these statistical associations from population studies may arise from characteristics common to people with such diets.
And this link is far stronger in people with the powerful genetic risk factor for Alzheimer's known as ApoE4, which affects fat and cholesterol blood profiles.
Conveniently for his case against “meat”, he does not mention poultry or fish, which have much less saturated fat (and iron) than red meats do.
Avoid all seafood, because “other” foods – by which Dr. Barnard meant plant foods – have all of the good fats you need.
This incorrect and irresponsible claim provoked Dr. Crawford's comment, “What that fellow says is based on monumental ignorance.”
First, the “long-chain” omega-3s in seafood (DHA, EPA, and DPA) are the ones our bodies actually need.
They are far more valuable to health than the short-chain omega-3 in plants (ALA), just one to 10 percent of which the body converts into the essential long-chain forms found only in fish and seafood.
Second, the few plant foods “high” (actually very small amounts) in omega-3s (walnuts, flaxseed, hemp seed, chia seed, and leafy greens) are proportionally much higher in omega-6 fats, which, as Dr. Crawford notes, “… the American diet delivers in the extreme excess linked to dementia and other major diseases.”
Finally, the evidence shows that discouraging fish consumption causes the brain-health harm it's alleged to prevent (by avoiding mercury).
Fish is loaded with these metals, because they live in “what is effectively the human sewer”.
Actually, fish are not loaded with iron, copper, and zinc.
Shellfish have relatively high levels of iron and zinc (two to three times more than fish) … but so do many of the plant foods urged by Dr. Barnard. See “Iron-Rich Foods
” at Web MD.
Oddly, Dr. Barnard didn't mention mercury, as that would have been a handy – if inaccurate – way to attack seafood.
It would be an inaccurate attack because the vast majority of fish are perfectly safe and positively healthful to eat despite traces of mercury.
The only exception is frequent consumption of the tiny minority of ocean creatures that contain significantly more mercury than selenium:
- Shark, swordfish, tilefish, and king mackerel
- Marine mammals (whales, seals, and porpoises)
We urge you to read the “Why is seafood so clearly safe, despite mercury?” section of our Purity Story page
, follow the links in it, and click the video links the sidebar titled “New science exposes most fish-mercury fears as baseless”.
As the authors of two evidence reviews concluded:
- “being subject to environmental influences from its habitat, seafood also entails water-borne health risks such as organic pollutants, toxins, parasites, and heavy metals. Nevertheless, the vast majority of experimental and epidemiological studies have proven that the benefits of fish intake exceed the potential risks even for vulnerable consumer groups.” (Oehlenschläger J 2012)
- “For major health outcomes among adults, based on both the strength of the evidence and the potential magnitudes of effect, the benefits of fish intake exceed the potential risks. For women of childbearing age, benefits of modest fish intake, excepting a few selected species, also outweigh risks.” (Mozaffarian D, Rimm EB 2007)
While 15 to 30 percent of the fats in fish are omega-3s (EPA, DPA, and DHA), the other 70 to 85 percent are a mixture of “bad fats and other fats that only fatten you up and don't do any good”.
The proportion of omega-3s to all other fats he cites is accurate, but very misleading.
Fish contain far more omega-3s – and in much greater proportions and far superior forms – than any other food.
Even the best plant-food sources of (nutritionally inferior) omega-3 fat (called ALA) have much smaller amounts (whether measured per serving or by weight) and produce very small amounts of essential, seafood-type omega-3s in our cells. Most of dietary ALA gets burned for quick energy, similar to dietary sugar.
And plant sources of omega-3s have greater proportions of omega-6 fats, which, as Dr. Crawford says, “the American diet delivers in the extreme excess linked to dementia and other major diseases.”
Whole plant foods don't deliver large amounts of omega-6s, but cheap vegetable oils do, including corn, soy, safflower, sunflower, and cottonseed.
Instead, use olive oil, macadamia nut oil, non-GMO canola oil, coconut oil, or hi-oleic sunflower oil.
Dr. Barnard recommends fortified soy milk as the source for vitamin B12 … which, as he said, is essential to brain health.
We're content to quote Dr. Crawford again:
“He fails to note that vegan diets are notoriously prone to B12 deficiency. And processed soy is high in omega-6 fats, which the American diet delivers in the extreme excess linked to dementia and other major diseases.”
We hope Dr. Oz shows better judgment in future, and at least challenges guests who make demonstrably bogus claims.
- Di Lorenzo F, Di Lorenzo B. Iron and aluminum in Alzheimer's disease. Neuro Endocrinol Lett. 2013 Nov 2;34(6):504-507. [Epub ahead of print]
- Dr. Oz Show. The Man Who Says You Can Prevent Alzheimer's. March 8, 2013. Accessed at http://www.doctoroz.com/episode/man-who-says-you-can-prevent-alzheimers
- González-Domínguez R, García-Barrera T, Gómez-Ariza JL. Characterization of metal profiles in serum during the progression of Alzheimer's disease. Metallomics. 2013 Dec 17. [Epub ahead of print]
- Grubman A, White AR, Liddell JR. Mitochondrial metals as a potential therapeutic target in neurodegeneration. Br J Pharmacol. 2013 Nov 11. doi: 10.1111/bph.12513. [Epub ahead of print]
- Harvard School of Public Health (HSPH). New Study Shows the Benefits of Eating Fish Greatly Outweigh the Risks. October 17, 2006. Accessed online September 10, 2008 at http://www.hsph.harvard.edu/news/press-releases/2006-releases/press10172006.html
- Jellinger KA. The relevance of metals in the pathophysiology of neurodegeneration, pathological considerations. Int Rev Neurobiol. 2013;110:1-47. doi: 10.1016/B978-0-12-410502-7.00002-8.
- Lee JY, Kim JH, Choi DW, Lee DW, Park JH, Yoon HJ, Pyo HS, Kwon HJ, Park KS. The association of heavy metal of blood and serum in the Alzheimer's diseases. Toxicol Res. 2012 Jun;28(2):93-8. doi: 10.5487/TR.2012.28.2.093. Mozaffarian D, Rimm EB. Fish intake, contaminants, and human health: evaluating the risks and the benefits.
- Mozaffarian D, Rimm EB. JAMA. 2006 Oct 18;296(15):1885-99. Review. Erratum in: JAMA. 2007 Feb 14;297(6):590.
- Oehlenschläger J. Seafood: nutritional benefits and risk aspects. Int J Vitam Nutr Res. 2012 Jun;82(3):168-76. doi: 10.1024/0300-9831/a000108. Review.
- Oken E, Kleinman KP, Berland WE, Simon SR, Rich-Edwards JW, Gillman MW. Decline in fish consumption among pregnant women after a national mercury advisory. Obstet Gynecol. 2003;102(2):346-51.
- Oken E, Osterdal ML, Gillman MW, Knudsen VK, Halldorsson TI, Strøm M, Bellinger DC, Hadders-Algra M, Michaelsen KF, Olsen SF. Associations of maternal fish intake during pregnancy and breastfeeding duration with attainment of developmental milestones in early childhood: a study from the Danish National Birth Cohort. Am J Clin Nutr. 2008 Sep;88(3):789-96.
- Oken E, Radesky JS, Wright RO, Bellinger DC, Amarasiriwardena CJ, Kleinman KP, Hu H, Gillman MW. Maternal fish intake during pregnancy, blood mercury levels, and child cognition at age 3 years in a US cohort. Am J Epidemiol. 2008 May 15;167(10):1171-81. Epub 2008 Mar 18.
- Park JH, Lee DW, Park KS, Joung H. Serum Trace Metal Levels in Alzheimer's Disease and Normal Control Groups. Am J Alzheimers Dis Other Demen. 2013 Oct 27.
- Park JH, Lee DW, Park KS. Elevated serum copper and ceruloplasmin levels in Alzheimer's disease. Asia Pac Psychiatry. 2013 May 9. doi: 10.1111/appy.12077. [Epub ahead of print]
- Rembach A, Hare DJ, Lind M, Fowler CJ, Cherny RA, McLean C, Bush AI, Masters CL, Roberts BR. Decreased copper in Alzheimer's disease brain is predominantly in the soluble extractable fraction. Int J Alzheimers Dis. 2013;2013:623241. doi: 10.1155/2013/623241. Epub 2013 Oct 21.
- Squitti R, Lupoi D, Pasqualetti P, Dal Forno G, Vernieri F, Chiovenda P, Rossi L, Cortesi M, Cassetta E, Rossini PM. Elevation of serum copper levels in Alzheimer's disease. Neurology. 2002 Oct 22;59(8):1153-61.
- Squitti R, Polimanti R. Copper phenotype in Alzheimer's disease: dissecting the pathway. Am J Neurodegener Dis. 2013 Jun 21;2(2):46-56. Print 2013.
- Zhao Y, Zhao B. Oxidative stress and the pathogenesis of Alzheimer's disease. Oxid Med Cell Longev. 2013;2013:316523. doi: 10.1155/2013/316523. Epub 2013 Jul 25