If you’re interested in protecting your brain health and preventing dementia, including Alzheimer’s disease, the research is pouring in in support of a key dietary strategy… namely, avoiding sugar and carbohydrates, including gluten.
Last year, I interviewed Dr. David Perlmutter—probably the leading natural medicine neurologist in the US, from my perspective—whose New York Times best-selling book, Grain Brain, has brought this issue to the forefront of medicine.
He recently expanded on this topic in an interview in Alternative and Complementary Therapies, where he cites even more research showing a high-carb diet may be detrimental to your brain.
Higher Blood Sugar Levels Are Bad for Your Brain
According to recent research published in Neurology, chronically higher blood sugar levels have a profoundly negative influence on cognition, which the researchers believe is “possibly mediated by structural changes in learning-relevant brain areas.
One of the most important aspects of the study, however, was that these negative effects occurred even in people without type 2 diabetes, which suggests even if you’re “healthy,” keeping your blood sugar levels lower than what is typically considered “normal” is probably still best for your brain health. The researchers noted:
“…strategies aimed at lowering glucose levels even in the normal range may beneficially influence cognition in the older population.”
This isn’t entirely surprising, as separate research has found that impaired insulin response was associated with a 30 percent higher risk of Alzheimer’s disease, and overall dementia and cognitive risks were associated with high fasting serum insulin, insulin resistance, impaired insulin secretion, and glucose intolerance.
However, the new study and another published last year suggest higher blood sugar levels may be detrimental to your brain even if you don’t have any of the former conditions.
It’s becoming increasingly clear that the same pathological process that leads to insulin resistance and type 2 diabetes may also hold true for your brain. As you over-indulge on sugar and grains, your brain becomes overwhelmed by the consistently high levels of insulin and eventually shuts down its insulin signaling, leading to impairments in your thinking and memory abilities, and eventually causing permanent brain damage.
High-Carb Diet May Increase Your Dementia Risk by 89 Percent
In one of the most striking studies on carbohydrates and your brain, researchers revealed that those who consumed higher amounts of carbs in their diets had an 89 percent increased risk of dementia. As for those whose diets were highest in fat… their risks decreased by 44 percent. Dr. Perlmutter says:
“We live with this notion that a calorie is a calorie, but at least in terms of brain health, and I believe for the rest of the body as well, there are very big differences between our sources of calories in terms of the impact on our health.
Carbohydrate calories, which elevate blood glucose, are dramatically more detrimental to human physiology, and specifically to human health, than are calories derived from healthful sources of fat.
The diet that I recommend—high in fat and low in carbohydrates—has simply been what we have eaten for a million years, so it has a bit of a track record. The notion that this is a revolutionary new diet has to be put into context. In reality, the diet that people are now consuming.
This is dreadfully high in carbohydrates and low in fat, as our governmental institutions are recommending, is the biggest challenge to human physiology that we have ever experienced, and this is very, very worrisome.”
One of the reasons why a high-carbohydrate diet is so damaging is due to fructose. You may already know I am passionate about warning of the dangers of refined fructose.
There is NO question in my mind that regularly consuming more than 25 grams of fructose per day will dramatically increase your risk of dementia and Alzheimer’s disease. Consuming too much fructose will inevitably wreak havoc on your body’s ability to regulate proper insulin levels.
Research also shows that rats fed fructose syrup showed significant impairment in their cognitive abilities—they struggled to remember their way out of the maze. They were slower, and their brains showed a decline in synaptic activity.
Their brain cells had trouble signaling each other, disrupting the rats’ ability to think clearly and recall the route they’d learned six weeks earlier. There is another component of a high-carb diet that may be equally as damaging, however.
Gluten Sensitivity May Also Harm Your Brain
Dr. Perlmutter stresses that gluten sensitivity is involved in most chronic disease, including those affecting your brain, because of how gluten affects your immune system. Unfortunately, many people, physicians included, still believe that if you don’t have celiac disease or digestive symptoms, gluten is fair game and you can eat as much of it as you like.
Full-blown celiac disease, which is an extreme form of immune-mediated gluten sensitivity primarily affecting the small intestine, affects an estimated 1.8 percent of people in Western cultures. But non-celiac gluten sensitivity may actually affect as much as 30 to 40 percent of all people, and according to Dr. Alessio Fasano at Massachusetts General Hospital, virtually all of us are affected to some degree.
This is because we all create something called zonulin in the intestine in response to gluten. These difficult to digest proteins known as prolamines, found in wheat, barley, and rye, make your gut more permeable, which allows undigested proteins to get into your bloodstream that would otherwise have been excluded. That then sensitizes your immune system and promotes inflammation and autoimmunity.
According to Dr. Perlmutter, much of our current disease burden stems from the fact that we are contaminating our immune systems with proteins to which the human immune system has never, in the history of humankind, been previously exposed to. I believe another major factor is the development of genetically engineered (GE) grains, which are now pervasive in most processed foods sold in the US.
These GE crops create proteins never before encountered in any natural grain or food, so GE grains deliver a double whammy against your immune system. Food allergies clearly appear to be one of the most noticeable side effects of a GE-grain diet. Dr. Perlmutter explains the role of gluten in brain health:
“In terms of gluten consumption, we have come a long way from our understanding that celiac disease exists, and we now recognize that, according to top researchers, non-celiac gluten sensitivity also exists, which may affect 30% of humanity. Marios Hadjivassiliou [MD, department of neurology, Royal Hallamshire Hospital, Sheffield, United Kingdom] has said, so poetically, that gluten sensitivity may at times be a pure neurologic disease that is basically extraintestinal, and that we do not need to have intestinal issues to define gluten sensitivity. In fact, we are now seeing literature that points the finger clearly at gluten sensitivity as a culprit in a variety of neurologic problems, including depression, cognitive dysfunction, seizures, and even headaches.”