According to a recent study, walking five miles per week may stall the decline of cognitive function among those who are experiencing mild forms of dementia.

To assess the impact that physical exercise might have on Alzheimer’s progression, Cyrus Raji, M.D., Ph.D., and colleagues analyzed the relationship between walking and brain structure in 426 adults. Among the participants, 299 were cognitively healthy and 127 were diagnosed as cognitively impaired.

For the study, participants were asked how many city blocks they walked in an average week. Follow-up questionnaires confirmed that the number of blocks remained steady over time. Participants also underwent MRI exams so researchers could measure changes in brain volume, and took the Mini-Mental State Exam, a test of cognitive skills, at various times throughout the study.

The study indicated that walking protects the brain structure in people with Alzheimer’s and mild cognitive impairment (MCI), specifically in areas of the brain’s key memory and learning centers. Raji stated that those who walked five miles per week also had a slower decline in memory loss over five years. In those diagnosed with MCI, the exercise reduced brain atrophy and cognitive decline by more than 50%.

The study also revealed that walking six miles per week is associated with a 50% reduction in Alzheimer’s risk in cognitively normal adults.