Moderate but Not Low-intensity Exercise Might Help Protect Brain from Alzheimer’s

People at risk for Alzheimer’s disease who spend more time doing moderate-intensity exercise have a healthier level of glucose metabolism in the brain — considered a reflection of how healthy and active the brain really is.

In contrast, low-intensity physical activity, such as a slow walk, was not related to brain metabolism, according to the research, published in the Journal of Alzheimer’s Disease.

The study, “Moderate Physical Activity is Associated with Cerebral Glucose Metabolism in Adults at Risk for Alzheimer’s Disease,” turned to the Wisconsin Registry for Alzheimer’s Prevention (WRAP) to obtain data about exercise levels and brain health.

“This study has implications for guiding exercise ‘prescriptions’ that could help protect the brain from Alzheimer’s disease,” Ryan Dougherty, first study author and a graduate student at the University of Wisconsin-Madison, said in a press release.

“While many people become discouraged about Alzheimer’s disease because they feel there’s little they can do to protect against it, these results suggest that engaging in moderate physical activity may slow down the progression of the disease,” he added.

WRAP recruits cognitively healthy people in their older middle ages who have one or both parents affected by Alzheimer’s disease. The registry also recruits people with no family history of the disease to use as controls.

Equipping 93 of these patients with accelerometers — a device that measures exercise by analyzing acceleration — the research team at the University of Wisconsin-Madison School of Medicine and Public Health got an idea of how much the participants exercised.

They then measured their brain glucose metabolism using a brain imaging technique called positron emission tomography (PET).

Moderate-intensity physical activity was related to brain glucose metabolism in all brain areas analyzed — areas that researchers know have abnormal glucose metabolism in people with Alzheimer’s disease. People who spent at least 68 minutes per day in moderate physical activity had better glucose metabolism readings than those who exercised less.

“Seeing a quantifiable connection between moderate physical activity and brain health is an exciting first step,” said Dr. Ozioma Okonkwo, an assistant professor of medicine and a researcher at the Wisconsin Alzheimer’s Disease Research Center and the Wisconsin Alzheimer’s Institute at the University of Wisconsin-Madison.

Okonkwo underscored that researchers are now trying to understand how exercise protects the brain from the disease processes of Alzheimer’s.