Jennifer Sygo: Lessons from Grain Brain and thinking of Alzheimer’s as type 3 diabetes

It may seem safe enough, diet-wise, but refined grains and sugars, like the ones found in breakfast cereal, breads and a host of other carbohydrate-heavy foods, may be the culprit behind Alzheimer's, or as some are now calling it "type 3 diabetes."

Can your diet help ward off Alzheimer’s disease? It’s entirely possible.

For years, research has focused on understanding the cause of this debilitating, progressive, and fatal disease, which is the most common form of dementia in Canada. And while a handful of vitamins, foods, and supplements — such as blueberries, fish oil, B vitamins, and gingko — have demonstrated modest, though often inconsistent effects on cognitive decline, there was little that could be said about preventing Alzheimer’s through diet.

Alzheimer’s risk raised by high blood sugar, even for those without diabetes: study

Higher blood-sugar levels, even those well short of diabetes, seem to raise the risk of developing dementia, a major new study finds. Researchers say it suggests a novel way to try to prevent Alzheimer’s disease — by keeping glucose at a healthy level.

Alzheimer’s is by far the most common form of dementia and it’s long been known that diabetes makes it more likely. The new study tracked blood sugar over time in all sorts of people — with and without diabetes — to see how it affects risk for the mind-robbing disease.

The results challenge current thinking by showing that it’s not just the high glucose levels of diabetes that are a concern, said the study’s leader, Dr. Paul Crane of the University of Washington in Seattle.

That is, until research in the last eight years or so began to demonstrate that Alzheimer’s may actually be a metabolic disease, brought on by abnormal blood sugars and insulin resistance (insulin is the hormone that helps regulates blood sugar, but chronically high insulin levels can eventually make our body less sensitive to its effects), developing in much the same way as type 2 diabetes. According to this new line of thinking, being overweight, inactive and eating an unhealthy diet that promotes insulin resistance may very well make us more prone to developing Alzheimer’s over time; the connection is strong enough that a number of experts in the field have euphemistically dubbed Alzheimer’s disease “type 3 diabetes” (type 1 diabetes, once known as juvenile diabetes, is an autoimmune disease whereby the pancreas ceases to produce insulin, causing blood sugar to rise dramatically in a short period of time; type 2 diabetes tends to develop more gradually, beginning with insulin resistance and elevated blood sugars tied to poor lifestyle and dietary choices).

At this relatively early stage of research, it is believed that insulin resistance can promote Alzheimer’s disease in a number of ways, including by disrupting the health of neurons in the brain, as well as by triggering abnormalities in a protein known as tau, as well as amyloid-beta precursor proteins, both of which have long been associated with the development of the disease. Insulin resistance also contributes to pro-inflammatory conditions in the brain, and can damage our DNA, both of which are also associated with the disease. While this theory is certainly an enticing one, there is still much to learn: Studies are ongoing to determine whether anti-diabetic drugs can slow the progression of the disease, for example.

Being overweight dramatically increases your likelihood of developing insulin resistance

So how can we protect ourselves from insulin resistance? According to Dr. David Perlmutter, author of the newly-released Grain Brain, eliminating grains, and more broadly, carbohydrate-containing foods from our diet is the key to preventing cognitive decline because of their contribution to insulin resistance. While Dr. Perlmutter’s strategy, of following a high-fat, low-carbohydrate diet (specifically, limiting carbohydrates to about 60 grams per day, or about the amount you would get from eating one piece of fruit, along with lesser amounts from the likes of non-starchy vegetables), has shown promise in the battle to control insulin, following the diet is much easier said than done. For the more moderate folks in the crowd, here are some simple strategies that can still do your brain plenty of good:

Maintain a healthy weight, and waist. Being overweight dramatically increases your likelihood of developing insulin resistance, and is also associated with impaired cognitive function over time. Men of Caucasian, Middle Eastern, and Eastern Mediterranean descent should target a waist circumference of 40 inches (102 cm), while women should aim for 35 inches (88 cm) or less. In East and South Asian and South and Central American populations, anything above 35 inches (90 cm) or 32 inches (80 cm) is considered high risk for men and women, respectively. If you are overweight, making any lifestyle change that will help you to lose weight and keep it off will improve your odds against not only Alzheimer’s, but heart disease, type 2 diabetes, and cancer, as well.

Get moving. When you exercise, your muscle cells become a depot, or dumping ground, for sugar (glucose); it also makes your body more sensitive to insulin’s effects. Even brisk walking can improve blood sugar control, and the effects of a single exercise bout can last up to 48 hours.

Reduce your intake of added sugars and refined carbohydrates. Some foods can cause more substantial spikes in blood sugars than others, which in turn means a greater reliance on insulin. Foods such as white bread, rice, crackers and pasta, sugary cereals, granola bars, desserts and sweetened beverages may have a particularly powerful glycemic, or blood sugar-raising effect. Reducing portions of these foods, or choosing healthier options (for example, water instead of pop) will help reduce your body’s reliance on insulin over time.

When you do eat carbohydrates, try to balance them with a source of protein or healthy fats. Portions, types of carbohydrates, and the foods we eat them with all have a role to play in your body’s ability to control blood sugars. Protein and fats delay the breakdown of carbohydrates into blood sugar, so balancing your meals and snacks can help to improve your glycemic control. For example, instead of a big plate of white pasta with tomato sauce, try a smaller portion with some chicken or meat sauce, and plenty of veggies. Likewise, instead of two slices of plain toast for breakfast, try one slice with an egg, a slice of cheese, or some peanut butter.

Eat your fruits and vegetables. While Dr. Perlmutter’s plan recommends strictly limiting fruit to keep a lid on carbohydrates, many fruits and almost all non-starchy vegetables have a modest effect on blood sugar, and have long been associated with a lower risk of developing degenerative diseases.