Facts of Life

Two new studies, both released in the Sept. 22 issue of the Journal of the American Medical Association, show a clear link between light, regular exercise — such as a daily stroll — and improved mental sharpness in old age. One study, involving more than 16,000 seniors, found that even subjects who walked a leisurely 90 minutes each week did better on tests of mental function than their less-active peers.

Register illustration by Tim Rauch