Brisk walk your way to Alzheimer's prevention

Want to keep Alzheimer's disease at bay? According to a recent study, you may want to put on those walking shoes and head to a park.

The University of Wisconsin-Madison study found that the people at risk for Alzheimer's disease, who do more moderate-intensity physical activity, but not light-intensity physical activity, are more likely to have healthy patterns of glucose metabolism in their brain.

The research involved 93 members of the Wisconsin Registry for Alzheimer's Prevention (WRAP), which with more than 1,500 registrants is the largest parental history Alzheimer's risk study group in the world.

Researchers used accelerometers to measure the daily physical activity of participants, all of whom are in late middle-age and at high genetic risk for Alzheimer's disease, but presently show no cognitive impairment. Activity levels were measured for one week, quantified and analyzed.

This approach allowed scientists to determine the amount of time each subject spent engaged in light, moderate, and vigorous levels of physical activity.

Light physical activity is equivalent to walking slowly, while moderate is equivalent to a brisk walk and vigorous a strenuous run.

Data on the intensities of physical activity were then statistically analyzed to determine how they corresponded with glucose metabolism, a measure of neuronal health and activity--in areas of the brain known to have depressed glucose metabolism in people with Alzheimer's disease.

To measure brain glucose metabolism, researchers used a specialized imaging technique called 18F-fluorodeoxyglucose positron emission tomography (FDG-PET).

Moderate physical activity was associated with healthier (greater levels of) glucose metabolism in all brain regions analyzed. Researchers noted a step-wise benefit: subjects who spent at least 68 minutes per day engaged in moderate physical activity showed better glucose metabolism profiles than those who spent less time.

"This study has implications for guiding exercise 'prescriptions' that could help protect the brain from Alzheimer's disease," said first author Ryan Dougherty. "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."

"Seeing a quantifiable connection between moderate physical activity and brain health is an exciting first step," said senior author Ozioma Okonkwo.

He explained that ongoing research is focusing on better elucidating the neuroprotective effect of exercise against Alzheimer's disease.

The study appears online in Journal of Alzheimer's Disease.

-ANI