Posted: Nov 1, 2012 8:47 PM
Nov. 1, 2012 -- Add lower risk for memory problems to the list of potential benefits from regular physical activity.
New research shows that older people who reported exercising for 30 minutes at least three times a week had a nearly 40% lower risk of dementia compared to people who were less active.
The study included 639 people who had an average age of 74. All participants were living independently and without disability. Of these people, 90 developed dementia during the three years of follow-up.
Dementia is an umbrella term for multiple types of mental disability, the most common being Alzheimer's. In this study, most of the dementia cases were cases of vascular dementia. Vascular dementia is related to inadequate blood flow in the brain.
About two-thirds of the people in the study said they exercised for 30 minutes a day three times a week. They were less likely to develop problems with thinking skills or dementia than their counterparts who did not get regular physical activity.
The risk for vascular dementia was reduced by nearly 60%. However, physical activity did not seem to affect the risk for Alzheimer's disease specifically.
The researchers also took MRI scans that looked at changes in the white matter in participants' brains. Such changes have been linked to dementia. All participants had changes of varying severity at the start of the study. The protective effects of exercise held even after researchers took into account factors that can affect memory and thinking ability, such as age, history of stroke, and diabetes.
"We have known for a long time that regular exercise helps reduce risk for heart attack and stroke, and now it looks like we are getting more and more evidence that physical activity reduces the risk of cognitive impairment, too," says American Heart Association spokesman Philip B. Gorelick, MD, MPH. He is the medical director of the Hauenstein Neuroscience Center at St. Mary's Health Care in Grand Rapids, Mich.
It's a win-win, he says. "Not only can you feel better and reduce your risk of heart attack and stroke, but you may reduce your risk of dementia, especially the kind of dementia that is related to stroke."
There is one caveat, he says. Get clearance from your doctor before starting an exercise program. "When you do get the go ahead, begin exercising in a gradual manner," he says.
There is no downside. "Even if it turns out that exercise does not lower your risk of cognitive decline or dementia, you will get reduction of heart attack and stroke. That is huge."
The new study adds to a growing body of research suggesting that exercise benefits the brain, says Patrick Lyden, MD. He is chair of the department of neurology at Cedars-Sinai Medical Center in Los Angeles.
"Assuming that your heart is strong enough for exercise, there is no downside, but you need check with your doctor first," he says.
The findings appear in Stroke.