Overview
- Nature Medicine analysis of 296 cognitively unimpaired adults reports that 3,000–5,000 daily steps were associated with roughly a three-year delay in modeled decline, rising to about seven years at 5,000–7,500 steps.
- Benefits appeared only in participants with elevated baseline amyloid, with no additional slowing observed beyond approximately 7,500 steps per day.
- Pedometer-measured activity was captured over one week at baseline, cognition was assessed annually for a median of about nine years, and PET imaging tracked amyloid and tau with repeat tau scans in a subset.
- Higher activity correlated with slower accumulation of tau rather than changes in amyloid, which largely explained the link to slower cognitive decline.
- Researchers and outside experts stress the observational design, note potential confounding or reverse causation, and outline plans for trials and deeper analyses of activity intensity and longitudinal patterns.