Overview
- The Nature Medicine analysis drew on the Harvard Aging Brain Study, tracking nearly 300 adults aged 50 to 90 with amyloid and tau present but no cognitive impairment using pedometers, PET imaging and annual testing.
- Higher daily step counts correlated with slower decline in memory and thinking and with slower accumulation of Alzheimer’s-related proteins, with benefits observed even at modest activity levels.
- Walking 3,001 to 5,000 steps per day was linked to measurable slowing of tau buildup and cognitive decline, and 5,001 to 7,500 steps appeared more beneficial.
- The study reported average delays in decline of about three years for people walking 3,000 to 5,000 steps daily and about seven years for those reaching 5,000 to 7,000 steps.
- Experts cautioned the findings are observational and cannot prove causation or confirm whether participants later developed dementia, urging physical activity as part of broader brain-health measures.