Exercising regularly in old age may better protect against brain shrinkage than engaging in mental or social activities, according to a new study published in the October 23, 2012, print issue of Neurology®, the medical journal of the American Academy of Neurology. Research suggests that brain shrinkage may lead to problems with memory and thinking.

"People in their seventies who participated in more physical exercise, including walking several times a week, had less brain shrinkage and other signs of aging in the brain than those who were less physically active," said study author Alan J. Gow, PhD, with the University of Edinburgh in Scotland. "On the other hand, our study showed no real benefit to participating in mentally and socially stimulating activities on brain size, as seen on MRI scans, over the three-year time frame." Researchers looked at medical records of 638 people from Scotland born in 1936. The participants were given MRI scans at 73 years old.

The group gave details about their exercise habits, ranging from moving only in connection with necessary household chores to keeping fit with heavy exercise or participating in competitive sports several times per week. They also reported their participation in social and mentally stimulating activities.

The study found that after three years, people who participated in more physical activity experienced less brain shrinkage than those who exercised minimally.

"Our results show that regularly exercising in old age is potentially important to protecting the brain as we age," said Gow.

The study was supported by Research Into Aging, the Age UK-funded Disconnected Mind Project and the United Kingdom's Medical Research Council.