Eating better is the key to a healthy brain, emphasizes a newly revised edition of the 2013 best seller Grain Brain: The Surprising Truth about Wheat, Carbs, and Sugar—Your Brain’s Silent Killers by Naples neurologist David Perlmutter.
“Management of blood sugar turns out to be the absolute cornerstone mechanism for heart disease, Alzheimer’s, cancer, and certainly for diabetes,” he says. “If you couple daily aerobic exercise with a low simple carbohydrate diet, you can at least cut your risk of Alzheimer’s in half.”
The renowned physician and author, who has made countless national media appearances from CNN to Fox News and from The Dr. Oz Show to The Oprah Winfrey Show, is the former medical director of the Perlmutter Health Center in Naples, which in 2015 became the Hughes Center for Functional Medicine.
Although many factors contribute to the development and progression of brain disease, Perlmutter writes, neurological problems often can be traced to the regular consumption of too many carbohydrates and too few healthy fats. This can result in elevated blood sugar levels, which lead, in turn, to disease. It is of utmost importance, he says, to keep your blood sugar in a healthy range.
Until recently, it had commonly been accepted that diseases such as cancer, Alzheimer’s, and heart disease were rooted in genetics. But in Grain Brain, which was revised in December, Perlmutter asserts that genetics are a much less important factor in the development of these conditions. Genes may play a part, he says, but the truth is that people who make wise lifestyle choices will be more likely to live longer, healthier lives.
Perlmutter grew up in Coral Cables and graduated from the University of Miami School of Medicine. While he first came to Naples for his medical residency, he decided to stay in part because he enjoyed fly fishing on the west coast. His late father, Irwin Perlmutter, also worked in neurology, acting as the first chief of neurosurgery for Jackson Memorial Hospital in Miami in the early 1950s. He spent the last few years of his life living in Naples before passing away in 2015 from complications linked to Alzheimer’s disease.
“People are very focused in this day of 23 and Me [a genetic test] about having the gene for this or the gene for that,” Perlmutter explains. “And there’s no question that there are genetic predispositions for Alzheimer’s disease. But these are absolutely not genetic determinants. There are people who don’t carry the gene and do get it. If you do carry it, no question you are at increased risk. But the biggest issue in terms of whether you do or don’t get it are lifestyle choices.”
Many of these lifestyle choices are well-known by now. Perlmutter outlines them in the latest edition of Grain Brain: Eat your vegetables. Brush your teeth. Sweat once in a while. Get plenty of rest. Don’t smoke. Laugh more. Be a member of a community. But beyond these, he says, what we put on our plates is tremendously significant in determining our health.
This is where vigilance about blood sugar comes in. “Today, we have a much better defined relationship between blood sugar levels and the risk for Alzheimer’s disease,” says Perlmutter, who has two grown children—an artist and a doctor— with his wife, Leize. “Research shows that people with Type II diabetes have as much as a four-fold risk of Alzheimer’s disease just by virtue of being diabetic.”
The ramifications of elevated blood sugar, meanwhile, also extend to heart disease. Cholesterol has long been a metric for increased risk of this condition. But as it turns out, “the idea that high cholesterol is the cause of heart disease is simply not accepted by mainstream medicine anymore,” notes Perlmutter, adding that, as with Alzheimer’s and most diseases, there are multiple factors that affect this condition.
Perlmutter, a four-time New York Times best-selling author and fellow of the American College of Nutrition, goes on to say that about half of all people with heart disease have cholesterol readings in the “normal” range. Furthermore, the majority of one’s cholesterol reading has very little to do with diet. Blood sugar, on the other hand, is absolutely influenced by what a person has been eating.
Another factor to note is that statins, which are heavily prescribed for high cholesterol readings, are linked to an increased risk of diabetes, says Perlmutter, who writes that statins may lessen brain function and lead to an increased risk of heart disease for some people. So, in an unfortunate twist, statins may encourage heart problems in some patients rather than help to ward them off.
What, then, does the Naples neurologist recommend we eat more of? “Diets should be higher in good fats and dramatically lower in simple sugars and processed carbohydrates,” he says. Good fats he encourages are olive oil, nut oils, avocado oil, fish oil, and nuts and seeds, and they’re also prevalent in foods such as avocados. “Dietary fiber is the one type of carbohydrate you don’t want to reduce.”
However, products that are labeled “whole grain” are most likely not high in fiber, the doctor notes. “To be classified as a whole grain food in America, a product has to be only 51 percent whole grain. The rest can be a highly processed, blood sugar–elevating carbohydrate. Good luck even trying to find whole grain wheat, corn, or rice.”
Lifestyle choices, by the way, are not all about food, the doctor emphasizes. Exercise is also critical. “The relationship between exercise and reducing Alzheimer’s risk is well documented. It is profound.” Another important factor in limiting Alzheimer’s disease is starting early. “The stage is set for Alzheimer’s 30 years ahead of time based on lifestyle choices,” he says. “Avoiding it is about being proactive in our 30s and 40s.”
Perlmutter adds that by the time you notice problems, chances are that you already have a significant amount of degeneration. “It’s a heck of a lot easier to prevent this disease,” he says, “than it is to intervene in it.”