David Perlmutter, MD, FACN, ABIHM discusses new edition of “Grain Brain”

When David Perlmutter MD, FACN, ABIHM, board-certified neurologist and New York Times bestselling author, originally published his book, “Grain Brain: The Surprising Truth about Wheat, Carbs, and Sugar—Your Brain's Silent Killers,” the medical community did not actively embrace the ideas put forward. Five years later, both the research landscape and public awareness has changed significantly to recognize the power of lifestyle interventions in preventing and reversing cognitive decline.

We sat down with Perlmutter to discuss his new edition of “Grain Brain,” which will be released later this month, how science has progressed to investigate the role of carbohydrates and gluten play in health, and how the message has moved to the mainstream.

Integrative Practitioner: What have been some of the most significant changes you’ve made in the new edition?

Perlmutter: Our message at its fundamental has not really changed. What has happened in the past five years is there has been huge validation globally on the ideas that we had put forth and a tremendous amount of research and scientific support in moving forward.

Our original contention was a higher dietary sugar, carbohydrates in general, and gluten were threatening to the brain. What’s happened over the past five years is those ideas have been borne out. We put forth a notion that gluten sensitivity could happen even without having Celiac disease. Back then, that was looked upon as being something no one wanted to embrace. Even five years ago, there was plenty of literature that suggested that to be the case. Now, we’re quite familiar with the term non-Celiac gluten sensitivity, even to the extent that it was published in the Journal of the American Medical Association in 2017. That is really pushing us towards the notion that something that was never in the human diet, gluten, is not something we would suddenly be able to tolerate or would suddenly be good for us.

The other big push of our recommendations over the years has been the idea that higher blood sugar, a derivative of a higher dietary sugar consumption, would be bad for the brain. That was what we talked about, even in the subtitle of the book, “The Surprising Truth about Wheat, Carbs, and Sugar—Your Brain's Silent Killers.” That was bold to say that, but it turns out that even when we first wrote the book, there was plenty of literature supportive of the notion that even mild elevation of blood sugar would be threatening to the brain, and that has absolutely been confirmed.

We now recognize that this major dietary shift in the developed world over the past 30 years away from dietary fat and towards higher levels of sugar and carbohydrates, has been profoundly detrimental not only towards health in general, but specifically with respect to the brain. When we see study after study demonstrating increased risk of cognitive decline—including a study published in the journal Diabetologia last year that correlates very directly the level of hemoglobin A1C, or average blood sugar, with cognitive decline—we have to take note. By in large, our blood sugar and A1C are markers of our sugar consumption. This becomes very important in a world where we do not have any treatment for Alzheimer’s disease whatsoever.

Everything that we can look at in the world of prevention, I believe, is hugely important, especially through the lens of not having any treatment for this disease. Recently, November 2, a study was published by the Journal of the American Medical Association demonstrating that not only were the two most commonly prescribed Alzheimer’s drugs ineffective, they actually are associated with speeding cognitive decline. To me, that’s [astonishing]. The very drugs people are being prescribed not only don’t work but are associated with increased rate of cognitive decline. This absolutely violates the notion of “above all do no harm.”

It’s not only that they’re not working, which would be heart-wrenching in and of itself, but they’re making people worse. For the vast majority of the 5.4 million Americans who have been diagnosed with Alzheimer’s and have been taking medications like good patients should, that’s a very sobering piece of information.

"Grain Brain" and the new revised edition are all about understanding that Alzheimer’s is, by and large, a preventable condition. Over the past five years, we’ve learned that these original ideas with reference to lowering dietary sugar, increasing dietary fat, and leveraging ketosis, physical exercise, quality of sleep, reducing stress, and taking various nutritional supplements can go a long way to keeping the brain healthy, happy, and disease-resistant.

Integrative Practitioner: Certainly, the science has changed, and the research landscape developed. What new knowledge do we have regarding gluten and dietary fat as it pertains to brain health?

Perlmutter: With respect to gluten, what we do understand is that gluten induces gut permeability in all people, not just if you happen to be gluten sensitive or a Celiac patient. There is a degree of increased gut permeability that is induced when anyone is exposed to gluten. That said, gut permeability is a key player in enhancing inflammation in the human body.

When we understand that Parkinson’s disease, Alzheimer’s disease, autism, coronary artery disease, cancer, are all inflammatory conditions, we need to do everything we can do to reduce inflammation in our bodies, and that includes eliminating gluten.

The other pathway to amping up inflammation in the human body is having a higher blood sugar. When we have high blood sugar, we change our proteins through a process called glycation, where sugar binds to protein. That’s what A1C is, for example: glycated hemoglobin, the hemoglobin protein bound to sugar. We know that when proteins are glycated, when blood sugar is elevated, it dramatically increases not only the production of inflammatory chemicals in the body, but also free radicals—damaging chemicals that damage fat, protein, and even our DNA. That’s another powerful argument with respect to keeping our blood sugars as low as possible.

We’ve just seen new research that demonstrates that women who have the highest intake of gluten during pregnancy compared to those who have the lowest intake, have an increased risk of their child becoming Type 1 autoimmune diabetic, the risk is doubled. This is a study out of Denmark that looked at close to 68,000 pregnancies over a 10-year period. Having high gluten during pregnancies is associated with doubling the risk of an autoimmune condition. That becomes very important when we recognize how immunity needs to be balanced in terms of protecting the brain. That to a significant degree, we are looking at some of these brain disorders now as being neuro-autoimmune conditions.

These are some of the ways that lifestyle is so important. The work of Kirk Erikson, PhD, a professor at the University of Pittsburg, in association with his colleagues at the University of California Los Angeles has clearly demonstrated that regular aerobic exercise is powerfully brain protective. We talked about their original work in the original version of "Grain Brain," they have redone their studies that have been much more extensive and shown not only that memory is improved in people who exercise, but there is increased size of the brain’s memory center called the hippocampus, and higher levels of what is called brain-derived neurotrophic factor (BDNF), which enhances the growth of new brain cells and their connectivity. Research in the American Medical Association also correlates lower levels of BDNF with increased risk for dementia.

One of the most powerful studies that we’ve quoted in the new book in the journal Neurology was an incredible study that evaluated people many years ago in terms of their inflammation markers in their blood. They followed these people for 24 years and followed two things, memory and the size of their brains or brain volume. What they found was quite interesting: there was a direct correlation between having higher markers of inflammation 24 years ago and risk for brain shrinkage as well as having poorer memory function. Memory function declines and the brain shrinks in lockstep with markers of inflammation. Markers of inflammation are higher if you have higher levels of abdominal fat, if you have higher levels of blood sugar, and these are things for which we have control based upon our lifestyle choices.

These are just some of the things that have evolved since "Grain Brain" was published, but again I believe play upon what we had originally talked about.

I have had the opportunity over the past five years to speak globally about these issues, including the fact that dementia is costing us globally $1 trillion a year, higher than the market value of Apple or Google; we have no treatment; and it is largely preventable.

This is in terms of the financial implications, but how do you put a dollar figure or a metric as it relates to the emotional cost of families of loved ones who are going through this and experienced it. Since "Grain Brain" was first published, my dad died of Alzheimer’s disease. That’s another new development that entered in to the revised edition. It keeps me doing my work.