Physical Activity May Stop Aging Brains From Shrinking, Study Shows

A study to be presented at an upcoming meeting of the American Academy of Neurology suggests physical activity may keep the brain four years younger and slow or prevent dementias like Alzheimer's disease, reports United Press International . The researchers utilized magnetic resonance imaging (MRI) scans of more than 1,550 people, average age 75, without dementia. Close to 300 had mildly impaired thinking and 28 percent carried the APOE gene, which appears to elevate the risk of Alzheimer's. The most physically active subjects had larger brains than those who were inactive, with the most active logging either seven hours of low-intensity physical activity, four hours of moderate activity, or two hours of high-intensity physical exercise per week. The average brain size of the most active participants was 883 cubic centimeters versus 871 cubic centimeters for inactive participants. That 12 cubic centimeter difference is equivalent to about four years of brain aging. The researchers caution that this does not prove that exercise preserves brain size, but simply appears to have a connection to this phenomenon.