Celiac disease is widely known to cause digestive problems. That's just the tip of the iceberg, according to the book Grain Brain : The Surprising Truth about Wheat, Carbs, and Sugar—Your Brain's Silent Killers, by David Perlmutter. The intestinal difficulties associated with celiac disease are caused by an immunological response triggered by gluten, similar to an allergic reaction but less violent. This response, which leads to inflammation in the gut, can happen elsewhere in the body too. Inflammation is at the root of many diseases and complications, including, Perlmutter argues, brain decay. Gluten can lead to inflammation in the brain, which Perlmutter believes leads to conditions like dementia and Alzheimer's.
A practicing neurologist, Perlmutter's experiences with patients and his study of medical research have led him to piece together a theory behind brain degeneration that's based on a foundation of gluten and high blood sugar. He also argues for the importance of cholesterol to maintaining brain health, and makes a compelling case that cholesterol-lowering statin drugs are bad for the brain.
Perlmutter says gluten teams up with high blood sugar to wreck the brain. The presence of high blood sugar, he explains, causes a reaction throughout the body called glycation, which he describes as "... the biological process whereby glucose, proteins, and certain fats become tangled together, causing tissues and cells to become stiff and inflexible, including those in the brain." Gluten, by triggering the immune system, causes inflammation in the brain, which encourages the brain's glycation by sugar circulating in the blood. And gram for gram, wheat raises your blood sugar more than sugar, Perlmutter writes.
Glycation can't be entirely avoided, but high blood sugar, as found in diabetics, Perlmutter writes, exacerbates it. When blood sugar is high, the brain is constantly bathed in a glycating sugar bath. Recent studies show that having diabetes doubles one's risk of contracting Alzheimer's disease, he points out, early and often. The growing understanding of the connection between the two diseases has prompted some researchers to suggest that Alzheimer's be re-labeled as "Type-3 Diabetes." "The origin of brain disease is primarily dietary," he concludes, and not hereditary, as is most commonly assumed.
There is a wide spectrum of gluten intolerance in the population, with celiac disease at the extreme end. Perlmutter recommends six markers you can have run on your own blood to determine your level of gluten intolerance. Along with these, not surprisingly, he also wants you to keep track of your fasting blood glucose and insulin levels.
But he could care less about your blood cholesterol numbers. Perlmutter falls into the increasingly populated camp that believes cholesterol does not cause heart disease. The neurologist takes it a step further by arguing that cholesterol is essential to proper brain function. Statins, which are prescribed to lower cholesterol, have been linked to problems with cognitive function, and Perlmutter presents recent evidence as to how that might be happening: The lowering of cholesterol levels muffles communication between neurons, and stifles the production of new brain cells.
Statins appear to influence the body's susceptibility to diabetes, as well. One recent, large study he points to "...demonstrated an astounding 48 percent increased risk of diabetes among women taking statin medications."
The book ends with a recipe section, filled with gluten-free, low-carbohydrate, high-fat meals. In some ways, these manifestations of Perlmutter's dietary protocols read like a sophisticated foodie's Atkins menu, with more vegetables. There are lusty recipes for steak, fish and other fatty meats, as well as dips, desserts and sauces. But some people might find themselves missing their favorite carbohydrate pleasures, like fruit, not to mention the grain-based likes of pasta and bread. And forget about that chocolate croissant: Perlmutter recommends a diet of 60 grams or fewer of carbohydrates per day.
Barely two months after publication, Grain Brain is already a bestseller, and many people are wondering if they should take drastic dietary action in order to save their brains.
Not surprisingly, the many dramatic dietary changes Permutter advocates have drawn their share of criticism. There are concerns about potential negative health consequences of a high-fat, low-carb diet, both in healthy people and for those with specific conditions, like adrenal or thyroid issues. The specific recommendation of 60 or fewer grams of carbohydrates per day has drawn a lot a blowback, including from active people who say that it simply isn't enough to sustain their lifestyles.
While people with certain neurological conditions, like epilepsy and muscular dystrophy, often respond very positively to a low-carb, high-fat diet, prescribing it to the population at large is jumping the gun, critics say. If your blood sugar isn't high, they argue, why avoid carbs? And turning away from whole fruit and whole grainseven gluten-free grainsis more extreme than even a lot of self-identifying low-carbers want to go.
But nobody is disputing the basic premise behind Perlmutter's theory of brain glycation, that gluten triggers an immune response in many people, which can lead to inflammation, which can lead to disease. And the connection between diabetes and Alzheimer's is on firm footing as well, although there remain more questions than answers.
And while Perlmutter focuses on the effect of gluten-triggered inflammation on the brain, there are other parts of the body that could be inflamed as well. This is a rapidly changing field, with much active research. For the moment, at the very least, Grain Brain makes a compelling case for getting a panel of blood markers for gluten sensitivity. If you're sensitive, experimenting with gluten-free diet is in order. And check your blood sugar.