Tufts University Health Letter, April 2013

 Here’s more evidence that walking helps boost your brain-but you might have to step it up: In a study of 299 Pittsburgh seniors, those walking at least 72 blocks weekly had significantly greater gray-matter volume in subsequent MRI scans.

Kirk Erickson, PhD, of the University of Pittsburgh, and colleagues studied people enrolled in the Cardiovascular Health Study, a long, multistate research project focused on risk factors for heart disease and stroke. Erickson and colleagues did additional research on 299 of the 1,479 Pittsburgh participants, all of whom were cognitively normal at the study’s start. Those participants, average age 78, also underwent MRI scans after nine years and were tested for mild cognitive impairment or dementia after 13 years.

Participants were divided into four groups based on weekly walking distance at the study’s start. The groups averaged 8, 21, 45, and 156 blocks per week. When scanned nine years later, those in the lower three groups of walking distance did not show significant difference in brain volumes, although there was a trend toward greater volume with increased activity. But the group averaging 156 blocks weekly had markedly greater volumes in three gray- matter areas of the brain-the inferior frontal gyrus, the hippocampal formation and the supplementary motor area.