Do Carbs, Calories Affect Alzheimer's Risk?

Reducing calorie and carbohydrate intake may affect Alzheimer’s disease (search) risk.

In a recent experiment, mice eating fewer calories and carbohydrates than those allowed to eat all they wanted showed no signs of Alzheimer’s-like disease, even though they had been bred to have the condition.

But don’t jump to conclusions. It’s too soon to know if the same is true for people, says psychiatry professor Giulio Maria Pasinetti, MD, PhD.

“While it is far too early for us to make specific recommendations for human diets, these findings provide the first solid evidence that dietary changes may prove to be a new approach to treatment and prevention of this devastating disease,” says Pasinetti in a news release.

Pasinetti and colleagues from New York’s Mount Sinai Medical School conducted the experiment. Their findings are due to appear in February in The FJ Express.

Fewer Carbs and Calories

The researchers wanted to see if cutting calories was beneficial against Alzheimer’s. Other studies have suggested that consuming too many calories might be an Alzheimer’s risk factor.

“There is epidemiological evidence that humans who consume reduced calorie diets have a lower incidence of Alzheimer’s disease,” says Pasinetti in the news release.

Pasinetti’s team used mice bred to have an Alzheimer’s-like brain disease. When the mice were 3 months old, the researchers divided them into two groups. One group ate a standard rodent diet. The other mice got 30 percent fewer calories. Calories were trimmed by reducing carbohydrates. Protein, fat, cholesterol, vitamins, and minerals were the same in both groups of mice.

After nine months, the mice brains were examined. The low-calorie, low-carb group “almost completely” avoided forming plaque in their brains, say the researchers. The same sort of plaque has been found in deceased Alzheimer’s patients’ brains.

The low-carb, low-calorie mice also matured normally and maintained a healthy weight.

“This rather mild change in diet resulted in a remarkable measure of disease prevention,” says Pasinetti in the news release.

The mice on the standard rodent diet weren’t as fortunate. They got no dietary protection against their brain disease. They also gained weight.

The low-calorie, low-carb diet may have unleashed a helpful chemical chain reaction. The low-calorie, low-carb mice had higher levels of a chemical that may break down plaque’s building blocks. That could have thwarted the plaque components before they had a chance to aggregate and clog the brain.

The researchers don’t know that for sure. It’s possible that the low-calorie diet influenced the brain in other ways. But there’s enough reason to keep studying diet and Alzheimer’s, they conclude.

By Miranda Hitti, reviewed by Brunilda Nazario, MD

SOURCES: Wang, J. FJ Express, February 2005. WebMD Medical Reference from Healthwise: “Alzheimer’s Disease --What Happens.” News release, Mount Sinai School of Medicine.