Long-term research into the relationship between activity levels, brain size and dementia risk among older adults has confirmed that exercise has a significant protective effect on the aging brain. The study, which was published online July 15, 2016 in advance of print in the Journal of Gerontology: Medical Sciences, tracked more than 3,700 adults ages 60 and older who participated in the long-running Framingham Heart Study.
After noting how often participants exercised and observing which participants eventually developed dementia, the researchers concluded that even a modest amount of exercise reduced the risk of dementia by 50 percent. The researchers also assessed the relationship between exercise and brain volume by looking at brain scans taken of approximately 2,000 of the participants. That analysis found that participants who regularly exercised—and especially those over the age of 75—also had less shrinkage of brain regions involved in cognition and memory, such as the hippocampus. Exercise is thought to slow brain aging by increasing circulation that nourishes brain cells and promoting the release of brain chemicals that encourage the growth and preservation of brain cells and their connections.