Walking may keep brain from shrinking in old age

"Walking at least six miles (10 km) a week may be one thing people can do to keep their brains from shrinking and fight off dementia, U.S. researchers said. A study of nearly 300 people in Pittsburgh who kept track of how much they walked each week showed that those who walked at least six miles (10 km) had less age-related brain shrinkage than people who walked less. "Brain size shrinks in late adulthood, which can cause memory problems. Our results should encourage well-designed trials of physical exercise in older adults as a promising approach for preventing dementia and Alzheimer's disease," said Kirk Erickson of the University of Pittsburgh, whose study appears in the journal Neurology. Alzheimer's disease, the most common form of dementia, slowly kills off brain cells, and activities like walking have been shown to build brain volume. Erickson and colleagues tested to see if people who walk a lot might be better positioned to fight off the disease. They studied 299 volunteers who were free of dementia and who kept track of how much they walked"