Three studies presented Monday at the Radiological Society of North America's annual meeting use imaging techniques to show how exercise can affect our bodies and brains.
Walking may slow cognitive decline in adults diagnosed with mild cognitive impairment and Alzheimer's disease, as well as benefiting brains of healthy adults.
In an ongoing 20-year study, participants are monitored for the distance they walk each week, and their brain volume is measured using MRI, combined with mental function testing, using the 30-question mini-mental state exam, which measures cognitive decline. Researchers are following 426 people, which includes 299 healthy adults and 127 cognitively impaired adults, including 83 with mild cognitive impairment and 44 with Alzheimer's disease.
"Volume is a vital sign for the brain," according to lead study author Cyrus Raji, PhD, from the University of Pittsburgh in Pennsylvania. "When it decreases, that means brain cells are dying. But when it remains higher, brain health is being maintained."
Participants walked between zero and 300 blocks per week. The researchers say greater amounts of walking were associated with greater brain volumes, especially in the key memory and learning areas of the brain. People with cognitive impairment needed to walk at least five miles - about 58 city blocks - per week to slow cognitive decline and maintain brain volume. Healthy adults needed to walk about six miles per week - at leat 72 city blocks - to maintain brain volume and reduce their risk for mental decline.