Would You Walk 6 Miles for a Healthier Brain?

Physical activity appears to help cognition and delay deterioration, but no longitudinal studies have monitored physical activity and later cognition and gray matter volume. In addition, how exercise affects biomarkers of Alzheimer disease (AD) is not clear. Two recent studies shed light on these topics.

In Erickson and colleagues' study, 299 cognitively normal adults (mean age, 78) underwent baseline measurements of physical activity (specifically, blocks walked during 1 week), magnetic resonance imaging (MRI) 2 to 3 years after baseline, high-resolution MRIs 9 years after baseline, and cognitive assessments at 9 and 13 years after baseline. At year 13, 116 participants were diagnosed with mild cognitive impairment (MCI) or dementia. Baseli…