Exercise keeps the brain fit

Some time in the early 30s, brain tissue starts to deteriorate. The decline continues over the next 60 years, so that by the time a person celebrates his or her 90th birthday, about 25% of tissue has been lost in areas that affect memory, learning and other thinking functions. Now, for the first time, researchers have physical proof that being physically fit slows this loss of brain tissue.

Sixty-eight people, age 55 to 79, had fitness tests and brain MRIs, or magnetic resonance imaging, as part of a study by researchers at the Beckman Institute at the University of Illinois at Urbana-Champaign. The volunteers were all well-educated and ranged in their level of fitness from the sedentary to competitive athletes. By comparing their MRIs, researchers were able to see greater amounts of gray and white matter in the active subjects. Gray matter is important in learning and memory, and white matter transmits signals throughout the brain. Cardiovascular fitness may help the brain stay young by increasing the growth of new blood vessels that feed the brain and by encouraging more connections between brain cells and, therefore, more processing power. And you don’t have to be a track star to reap these benefits, says lead author Stan J. Colcombe, a cognitive neuroscientist at the University of Illinois: “Just 15 to 20 minutes of moderate activity, such as walking, three times a week is enough to produce a benefit.”

The study was published in the February issue of the Journal of Gerontology: Medical Sciences.