More than seven million Americans currently live with Alzheimer’s disease, a figure projected to nearly double by 2050. New research from Mass General Brigham offers actionable data on slowing cognitive decline through moderate physical activity.
Researchers found that individuals with elevated amyloid-beta protein levels who walked between 3,000 and 5,000 steps daily delayed cognitive decline by an average of three years. Increasing daily activity to between 5,000 and 7,500 steps extended this protective window to seven years.
Published in Nature Medicine, the study analyzed 296 participants aged 50 to 90 within the Harvard Aging Brain Study. Scientists utilized brain scans and waistband pedometers over nine years to track tau protein accumulation and cognitive function.
Dr. Jasmeer Chhatwal of Mass General Brigham notes that lifestyle factors impact the earliest stages of the disease. Sedentary participants with high amyloid-beta experienced faster tau buildup and rapid functional decline, while active counterparts showed significantly slower progression.
The findings suggest physical activity specifically targets tau pathology in at-risk populations. However, for individuals with low baseline amyloid-beta levels, increased step counts did not significantly alter cognitive trajectories, indicating targeted benefits for those already on a pathological pathway.