Grain Brain: The Surprising Truth about Wheat, Carbs, and Sugar—Your Brain’s Silent Killers
David Perlmutter, MD with Kristin Loberg
Little, Brown and Company 2013
Grain Brain is an ambitious book. Both in style and substance, it is technical enough to provide justification for the dietary principles it espouses, but won’t bog down a less science-savvy reader. The biggest question the book raises for this reviewer is in the soundness of its thesis: are carbohydrates really brain killers?
As its full title suggests, Dr. Perlmutter’s book focuses not solely on grains, but on carbohydrates in general. It takes time to address the fact that modern grains often bear little resemblance to their forbears: “…[because of] modern hybridization and gene-modifying technology, the 133 pounds of wheat that the average American consumes each year shares almost no genetic, structural, or chemical likeness to what hunter-gatherers might have stumbled upon” (page 8). It is interesting to note that while one hundred thirty-three pounds of wheat seems like a lot, numerous other countries consume double or more this amount per person annually, and yet their populations don’t suffer the same health troubles at the same rate as Americans. Even more interesting, we Americans consume four or more times that amount of dairy products, most of which are highly processed industrial milk products from confinement dairy operations.
Second, there is some information that, from a historical perspective, is problematic. Not only does Perlmutter recommend completely eliminating grains from the diet, he further advises to radically restrict carbohydrate consumption to a scant 60 grams per day, or just two ounces. He admits that this is the equivalent of merely a single piece of fruit per day.
His discussion of inflammation, oxidation, diet, and disease is intriguing, but incomplete, as the focus on carbohydrates and grains means that other likely contributors or culprits, like the increased consumption of PUFAs in the general American diet and rancid, overly processed vegetable oils, as well as processed foods in general, are given little consideration or inclusion. Chapter 3, which focuses on fat, cholesterol and statin drugs, is excellent, exonerating saturated fat and cholesterol while indicting statins for the shell game that they are. Perlmutter also takes time to point out that these drugs are well known in his field of neurology to harm the brain, whose dependence on cholesterol for proper functioning is well documented. Perlmutter further reveals other dangers of statin drugs, such as an increased risk of type 2 diabetes.
It is when he gets onto the topic of carbohydrates that some inconsistencies seem to emerge. On the one hand, refined carbs and processed foods are rightly spotlighted as destructive to health. Perlmutter even admits, “Not all carbohydrates are treated equally by the body” (page 106). His discussion of fruit consumption has a few historical flaws, given that some native peoples indeed had access to fruit year round and some of the fruits they consumed were exceptionally high in sugar and low in fiber. (Denise Minger on her rawfoodsos.com blog has a wonderful, picture-laden article on this subject, http://rawfoodsos.com/2011/05/31/wild-and-ancient-fruit/) Perlmutter does cite many excellent studies that show the dangers of obesity, especially to brain health, and the importance of maintaining healthy insulin levels and exercising as ways to protect not only the brain, but the entire body from various degenerative diseases.
Yet the brain requires not only cholesterol to function well, but a certain supply of glucose. To argue for the necessity of the former while neglecting the importance of the latter does injustice to clear metabolic needs of the body. While the body can manufacture glucose from protein and utilize ketone bodies from fat metabolism, not everyone is equipped to function perfectly in this manner without some additional source of carbohydrates. Just as the body can adapt to a low-cholesterol diet, it can also adapt to a low-carb diet, but this does not mean that such a diet is optimal for everyone everywhere and at all times.
Many indigenous peoples of the past few thousand years with excellent cognitive and physiological development consumed moderate to copious amounts of carbohydrates (especially compared to a restricted regime of 60 grams a day), some in the form of grains. Many individuals do not do well on highly restrictive, low-carb diets for an extended time. It is worth noting that many healing dietary protocols temporarily reduce and restrict carbs, but this is not because carbs are inherently bad or dangerous. Rather, we moderns—exposed from infancy to antibiotics, overly sanitized lifestyles, lack of fermented foods, miserable dietary habits, and so on—find ourselves with a compromised and damaged microbiota. Restricting carbs seems to help many people recover from this damage (some, but not all, people achieve healing by eliminating the wrong kinds of carbohydrate sources and incorporating the right kinds).
Grain Brain also includes information on caloric restriction that a number of other works have shown to be incorrect or at least partially so. If the figures cited are true (the average person in United States consumes a bit under 4,000 calories per day), then for many people, reducing this number by 25-30 percent isn’t so much a caloric restriction as a caloric readjustment to levels both more historically accurate and normal for their lifestyles. Interestingly, some of the benefits of caloric restriction may be achievable through ancient practices, such as short-term fasting, something not considered or discussed by Perlmutter, whereas the dangers of longterm caloric restriction are not mentioned at all.
Overall, this book gets a mixed thumbs review. If carbohydrates, including sweet fruits and starchy vegetables and grains are inherently damaging to our health and especially to the nervous system, then many indigenous populations that Dr. Price and others have studied must have missed that memo. Does gluten cause damaged guts or are damaged guts no longer able to digest gluten? Do people benefit from removing gluten from their diet because gluten is harmful or because they have harmed themselves to the point where now normal foods hurt? Or is it because we have tampered with the genetics of grains to the point where our bodies no longer recognize the proteins in them as friends, but treat them as foes? How do traditional preparation techniques on truly organic grains affect all of the above? These are complex questions that elude easy answers such as blaming the entire macronutrient category.
Blame needs to be assigned where it clearly belongs: on our tampering with the genetics and nutritional value of our foods, on our abuse of growing systems through herbicides, pesticides, fungicides and a host of other chemicals that contaminate our foods and render them nutritionally deficient, and on our further destruction of these foods through industrial processing. Contributing factors such as our genetic differences and the many ways American health has steadily declined in the past century also need to be considered as to why some people do well and others do not with carbohydrate foods in the diet.
But the case against carbohydrates as an inherently dangerous and damaging macronutrient isn’t sound, and people ought to enjoy their traditional sourdough breads (if they do well on them!), organic seasonal fruits, and organic starchy vegetables with a sure spirit that suchfoods help rather than harm the majority of bodies and souls. A very qualified Thumbs Up.
This article appeared in Wise Traditions in Food, Farming and the Healing Arts, the quarterly journal of the Weston A. Price Foundation, Fall 2015