Have you heard of the #1 New York Times bestseller Grain Brain? In it, Dr. David Perlmutter argues that wheat, carbs, and sugar are the brain’s “silent killers.” He recommends going completely gluten-free and using fat as your main fuel source.
1.5 million people have read his book, and while it has made quite a splash, I must respectfully disagree. Through decades of research and practice, I have come to believe that wheat, in its natural whole grain state, is beneficial in season, and that removing digestive irritants like wheat and dairy will only further weaken our digestion, as we are treating symptoms, rather than getting to the root of digestive disturbances.
In early 2016, Dr. Perlmutter and I had a live debate based on the tenants of my then-new book Eat Wheat. We both received much praise for our ability to come together, share our differences, and do so with incredible respect for one another.
It is important to note that my mother said I won that debate back in 2016. But that did not slow the $16 billion per year gluten-free industry from somehow convincing folks that all wheat is bad and that highly-processed gluten-free alternatives are healthier.
Dr. Perlmutter has totally updated and revised Grain Brain, so I invited him to come on my podcast for Round 2 of this important debate. Dr. Perlmutter is still firmly against gluten, grains, and carbs and cites new research promoting a ketogenic diet. In chapter 1, he presents an unreferenced graph suggesting that our ancestors ate a diet of 75% fat and only 5% carbohydrates.
Unless you live in the Arctic Circle, I could not find any evidence from any published anthropologists that we maintained a diet of 75% fat and 5% carbohydrates. In fact, one of the most respected sources on this matter, Harvard professor Daniel Lieberman, author of The Story of the Human Body, cites the most current thinking that our ancestors ate 20–35% fat and 35–40% carbohydrates.1
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I do believe we all went into ketogenesis during periods of famine in late winter and spring, but once the fruits, tubers, grains, and beans were ripe in the late summer, we quickly left ketosis for a higher carbohydrate diet. I believe that seasonal eating plus time-restricted eating (intermittent fasting) based on circadian rhythms is how we got here and explains why there is positive research supporting both a high-fat ketogenic diet as well as a high-starch carbohydrate diet.
Stay tuned for my upcoming podcast with high-starch vegan expert Dr. John McDougal. Subscribe for updates here.
I wrote about the importance of time-restricted eating and seasonally shifting the diet back in 2000 in my book The 3-Season Diet, where I discuss time-tested Ayurvedic principals, including eating only two meals a day (by skipping supper) and the absolute necessity of seasonal eating.
I also publish a free monthly seasonal eating guide that includes recipes, grocery lists, and superfoods for every month of the year. Sign up free here.
Dr. Perlmutter agreed that seasonal shifts in eating did occur and that his current thinking (which did not make it into his newly revised edition) is leaning more toward a cyclical ketogenic diet, while maintaining being totally gluten-free.
Today the debate on whether we should eat a high-fat ketogenic diet or a high-carb vegan-like diet sports science on both sides, with little common ground in sight. Logic (the basis of Ayurveda), however, clearly suggests that we did swing seasonally from a high-carb to a high-fat diet seasonally.
We are all designed to shift from a higher-protein, higher-fat diet in the winter to a famine-like, ketogenic diet in the spring, and then to a higher-carb (yes, grains included!) diet in the summer.
This is now backed by recent studies on gut microbiomes of the last remaining hunter-gatherer tribe. Researchers found that their gut bacteria shift dramatically from season to season, as they eat more meat during the dry season and more fruit and veggies during the wet season.2
Treat the Cause + Challenge Your Digestion
In Eat Wheat, I cite 600 scientific papers backing the importance of seasonal eating and not taking foods like grain, beans, nuts, and seeds (that may be hard to digest) out of the diet. Of course, if you are wheat sensitive, I suggest to stop eating wheat for a while, as you repair your digestive imbalance.
That is the purpose of my book: to help you not only treat the symptom of wheat intolerance by taking wheat away, but rather to troubleshoot the source of your digestive issue and treat the cause.
There are consequences of globally taking wheat and grain out of the diet if you are not celiac. I have written about this in my article The Dangers of a Gluten-Free Diet and report on two new Harvard studies that follow hundreds of thousands of volunteers for 30 years, which have found links between a gluten-free diet and increased risk of heart disease and diabetes.
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The group that consumed the highest percentage of gluten had a 15% reduction in heart disease and a 13% reduction in diabetes—the opposite of what Dr. Perlmutter argues in Grain Brain.3, 4
Most folks, when they go gluten-free, end up with a dangerously low-fiber diet, which is also linked to heart disease and diabetes.
Dr. David Perlmutter + Dr. John Douillard Find Common Ground
In this very compelling podcast, Dr. Perlmutter finally does agree with the seasonal and circadian evidence-based logic regarding consumption of wheat. In departure from his newly revised Grain Brain, Dr. Perlmutter stated that wheat—with gluten, made from the whole grain, not white bread form the grocery store—can be safely eaten in season!
I love finding thinkers who are as passionate about diet and health as I am. It has been a great joy and honor to share and debate with Dr. Perlmutter—twice! I’m so curious if our conversations will change any minds and diets.