| Potentially edible!|
“”Taken as a whole, Perlmutter’s career — his support for unproven treatments, his profiting from those treatments, his endless “miracle”-talk — suggests he probably isn’t a misunderstood genius who will be vindicated by time. Rather, his work places him squarely in the medical arm of the self-help industry, which stars figures like Dr. Oz (who has hosted Perlmutter and blurbs his books) and the notorious anti-vaccine quack Dr. Joseph Mercola (Perlmutter wrote the foreward to Mercola’s latest best seller, Effortless Healing).
|—Professor Alan Levinovitz on Perlmutter|
Perlmutter is known for promoting bizarre health claims including eating carbohydrate increases the risk of dementia and high levels of blood cholesterol are healthy for the brain. He has been criticized by medical experts for making dangerous and misleading health claims unsupported by scientific evidence. Perlmutter is known to change his views on nutrition depending on his audience, for example, he used to criticize fruit consumption but now recommends it in moderation. Quackwatch has noted that "much of what Perlmutter is now saying is the opposite of what he wrote—just as confidently—15 years ago."
Perlmutter wrote a bestseller called Grain Brain in 2013 which launched a bunch of nutty sequels. His book series claims that gluten grains and sugar are destroying people's health by causing practically every mental or neurological disorder such as ADHD, Alzheimer's disease/dementia, depression, Tourette’s syndrome, anxiety, epilepsy, movement disorders, migraine and schizophrenia. He says that grains, including whole grains, are "a terrorist group that bullies our most precious organ, the brain."
Perlmutter claims our ancestors ate a high-fat low-carb diet but he failed to back this up with any reliable evidence:
On page 6, Grain Brain states "I believe that the shift that has occurred over the past century—from high-fat, low-carb to today’s low-fat, high-carb diet, fundamentally consisting of grains and other damaging carbohydrates—is the origin of many of our modern scourges linked to the brain, including chronic headaches, insomnia, anxiety, depression, epilepsy, movement disorders, schizophrenia, attention deficit hyperactivity disorder (ADHD), and those senior moments that quite likely herald serious cognitive decline and full-blown, irreversible, untreatable, and incurable brain disease." The book doesn’t provide a reference to support this statement. In fact, the best historical data we have on the US diet are from the US Department of Agriculture. These data go back to 1909, and suggest that the US diet a century ago was probably higher in carbohydrate and lower in fat than what we eat today. Total carbohydrate intake was also higher. Worse, our consumption of wheat flour—the arch-nemesis of Grain Brain due to its concentrated carbohydrate and gluten—was higher a century ago than it is today. This claim in Grain Brain is not only incorrect, it’s backward. — Stephan Guyenet
Perlmutter promotes a very-low-carbohydrate ketogenic diet which is very high in saturated fat for brain health and to prevent neurodegenerative diseases such as Alzheimer's disease (AD) but there is no scientific evidence that such a diet is effective to prevent the disease. Contrary to what Perlmutter claims, reviews of studies have found that higher saturated fat consumption increases the risk of AD and dementia. Perlmutter rarely cites reviews of studies such as meta-analyses and most of the scientific sources he cites have small sample sizes.
Another of Perlmutter's claims is that a ketogenic diet is beneficial for the heart, although no long-term clinical trials have demonstrated this.
Perlmutter's statements about non-gluten grains have confused reviewers. Science writer Alex Ruani noted that "it isn’t always clear whether Perlmutter is discussing the effects of carbohydrates or gluten, as the language shifts throughout. To add to the confusion around exactly what Perlmutter links to the cause of neurological degeneration, in the diet section of Grain Brain, carbohydrate-containing foods such as legumes, rice, quinoa, and oats are allowed to be included."
Perlmutter allows moderated consumption of amaranth, buckwheat, rice (brown, white, wild), millet, quinoa, sorghum, teff and gluten-free oats so contrary to what has often been reported he is not anti-grain, he only opposes grains that contain gluten.
Perlmutter is an anti-sugar fanatic. He has claimed that all sugar including fructose is bad for health and that people should limit their fruit consumption to a few berries. In his book Grain Brain and in interviews on YouTube Perlmutter has advised people to limit their fruit consumption but in June, 2021 he admitted on his website that "up to three servings per day is actually associated with lowered risk of type 2 diabetes." This contradicts the statements in his book.
Since writing Grain Brain, Perlmutter has changed his views about fruit. He now claims "there's nothing wrong with fruit" but it should be consumed in moderation.
“”If there’s one health myth worth dispelling, it’s the long standing falsehood that fat clogs the arteries and that’s what causes heart disease.
Perlmutter is a cholesterol denialist and he thinks that everyone should eat a diet high in saturated fat because LDL cholesterol does not cause or increase the risk of cardiovascular disease. This advice has been described as dangerous:
[Perlmutter's] second claim is that high levels of blood cholesterol are healthy for the brain, including the so-called “bad” LDL cholesterol that causes cardiovascular disease. This is not only probably incorrect, it’s also dangerous. Grain Brain cites evidence that high blood cholesterol late in life is associated with better brain health and greater longevity. What it fails to consider is that dementia, like cardiovascular disease, is a condition that develops progressively over a long period of time. If we want to understand what causes it, we have to look at what’s happening in the years before it’s diagnosed. To get a clearer picture of this, I located a meta-analysis (study of studies) that examined the association between blood cholesterol levels and dementia in both midlife and late life. Meta-analyses give us an overview of the whole research literature and help protect against cherry-picking. This study found that high blood cholesterol in midlife is strongly associated with the later development of Alzheimer’s disease, and high blood cholesterol in late life has no association with risk. This shouldn’t be surprising. Overwhelming evidence suggests that high levels of LDL cholesterol damage the blood vessels, leading to cardiovascular disease and inflammation (a fact that Grain Brain denies), and cardiovascular disease is probably harmful to the brain. — Stephan Guyenet
Perlmutter bizarrely claims that a ketogenic diet might actually reduce risk of heart disease. There is no reliable evidence for this in the medical literature.
On his website in the past Perlmutter has sold a bunch of vitamin woo and other pseudoscientific nonsense including a $90 "Scholar’s Advantage Pack" for "young adults seeking to optimize cognitive function," and the $160 "Senior Empowerment Pack," a "combination of formulas designed to help keep you cognitively sharp as you age." Perlmutter has run a $8,500 brain detoxification retreat which has included shamanic healing ceremonies.
In 2018, Perlmutter teamed up with the vitamin supplement company Garden of Life® to sell "Dr. Formulated Brain Health" supplements that are alleged to improve "mental sharpness". One of these products, "Dr. Formulated 100% Organic Coconut MCT Oil", is said to provide "fast fuel for brain and body" and is recommended to those on a ketogenic or paleo diet.
- Grain Brain: The Surprising Truth About Wheat, Carbs, and Sugar– Your Brain’s Silent Killers Written by David Perlmutter], reviewed by Stephan Guyenet (May 9, 2018) Red Pen Reviews.