Seniors who rarely exercise have 50% higher risk of dementia

Older adults who don't exercise often — or don't exercise at all — have a 50% higher risk of developing dementia as they age, according to a new study in the Journals of Gerontology: Medical Sciences.

Researchers split a group of 3,700 participants of the Framingham Heart Study into five sub-groups based on activity levels. Results of the study showed the group containing the most sedentary people had the highest risks of developing dementia compared to the other four groups. Seniors over age 75 who exercised showed the most benefits and protections against dementia.

Even small amounts of moderate physical activity, such as brisk walking, ballroom dancing or gardening, helped the participants' brains stand up to the effects of aging, researchers found. Those benefits could be due to increased blood flow to the brain experienced during exercise, as well as increase secretion of chemicals that encourage growth of new neurons.

"It doesn't require intensive physical activity to decrease risk of dementia," said lead researcher Zaldy Tan, M.D., director of the University of California - Los Angeles' Alzheimer's and Dementia Care Program. “The message here is that you're never too old to exercise and gain benefit from it.”