Even a Little Exercise May Help Stave Off Dementia
Couch potatoes have a higher risk of developing dementia in old age, a new study reports.
Seniors who get little to no exercise have a 50 percent greater risk of dementia compared with those who regularly take part in moderate or heavy amounts of physical activity, the researchers found.
Moderate physical activity can include walking briskly, bicycling slower than 10 miles an hour, ballroom dancing or gardening, according to the U.S. Centers for Disease Control and Prevention.
"It doesn't require intensive physical activity to decrease risk of dementia," said senior researcher Dr. Zaldy Tan. He is medical director of the Alzheimer's and Dementia Care Program at University of California, Los Angeles. "Even moderate amounts are fine."
Study participants aged 75 or older gained the most protective benefit from exercise against the onset of dementia, the findings showed.
"The message here is that you're never too old to exercise and gain benefit from it," Tan said. "These patients derive the most benefit from exercise because they are the ones who are at the age of greatest risk for dementia."
Brain scans of participants showed those who exercise are better able to withstand the effects of aging on the brain, the study authors said.
With age, the brain tends to shrink. But people who regularly exercised tended to have larger brain volumes than those who were sedentary, Tan and his colleagues found.
The new study involved about 3,700 participants in the Framingham Heart Study, a federally funded health research project begun in 1948. All were 60 and older.
Researchers measured how often the participants exercised, and tracked them over a decade. During the study, 236 people developed dementia.
To see how physical activity might have affected dementia risk, the researchers broke the study population down into fifths that ranged from sedentary to highly active.
The one-fifth containing the most sedentary people were 50 percent more likely to develop dementia than the other four-fifths, the investigators found. In other words, even a little exercise helped.
"Given that there's no harm, and there's a possible benefit to the brain that hasn't been fully explained, I work with my patients and their families to help improve their physical activity," he said.
The findings were published online recently in Journals of Gerontology: Medical Sciences.