May 18, 2016
Physical activity can dramatically cut the risk of developing Alzheimer’s disease in old age, according to a new report. The study found that whether older people swam, jogged, gardened or danced, parts of the brain that were critical for memory and thinking remained more robust than their sedentary peers. The findings add to a growing body of evidence that exercise is good the brain and may help to ward off Alzheimer’s disease and other forms of dementia in old age.
“Our current treatments for dementia are limited in their effectiveness, so developing approaches to prevent or slow these disorders is crucial,” said study author Dr. James T. Becker, a professor of psychiatry at the University of Pittsburgh School of Medicine. “Our study is one of the largest to examine the relationship between physical activity and cognitive decline, and the results strongly support the notion that staying active maintains brain health.”
For the study, published in the Journal of Alzheimer’s Disease, researchers at the University of Pittsburgh and UCLA analyzed data from 876 men and women over 65 who were part of a large and multi-year nationwide study of seniors and heart health. All were given regular MRI brain scans and tests of memory and thinking skills to look for signs of dementia. They also completed weekly questionnaires about how often they engaged in physical activities like walking, jogging, playing tennis or golf, riding a stationary cycle at the gym, or gardening.
The researchers found that those who expended the most calories – whatever their activity of choice – had the most robust brain volume in parts of the brain critical for memory and thinking. Those who were most active had larger brain volumes in key areas on initial brain scans and were half as likely to have developed Alzheimer’s disease five years later.
The investigators also found that physical activity appeared to protect the brains of those presenting with mild cognitive impairments, a form of memory loss that often precedes Alzheimer’s. Those with Alzheimer’s or memory problems who exercised the most had greater brain volume than their peers who got little or no exercise.
“We noted that brain volumes increased if people became more active over five years leading up to their brain MRI,” said Dr. Cyrus Raji of UCLA, a study author. This is really important, and shows that it is never too late to go back to having some level of physical activity. He added that in the future, it might be useful for doctors prescribe exercise regimens in people who are at risk for dementia to help prevent further memory deterioration. “Rather than wait for memory loss, we might consider putting the patient on an exercise program,” he said.
The authors note that among Americans aged 75 and older, over half of men and two-thirds of women engage in no leisure-time physical activity. But this is a time when older people are most at risk for Alzheimer’s disease and other forms of dementia, so they should be encouraged to exercise. (Check with your doctor beforehand, of course, to determine a level that’s safe for you.)
At present, “we have no magic bullet cure for Alzheimer’s disease,” Dr. Raji said. “Our focus needs to be on prevention. This is the first study in which we have been able to correlate the predictive benefit of different kinds of physical activity with the reduction of Alzheimer’s risk through specific relationships with better brain volume in such a large sample.”
By www.ALZinfo.org, The Alzheimer’s Information Site. Reviewed by Marc Flajolet, Ph.D., Fisher Center for Alzheimer’s Research Foundation at The Rockefeller University.
Source: Raji, Cyrus A.; Merrill, David; Eyre, Harris; et al: “Longitudinal Relationships between Caloric Expenditure and Gray Matter in the Cardiovascular Health Study.” Journal of Alzheimer’s Disease, March 11, 2016