Physical inactivity links to cognitive impairment up to age 90
Being sedentary was linked to cognitive impairment between ages 78–85 (odds ratio 2.61) and ages 85–90 (odds ratio 2.90) in older adults.
Journal of Alzheimer's Disease
Researchers followed community-dwelling human adults born between 1920 and 1921 in the Jerusalem Cross-sectional and Longitudinal Study from 1990 to 2023. Participants underwent evaluations at ages 70, 78, 85, 90, 95, and 100, with sample sizes ranging from 1,222 at age 85 to 205 at age 100. Investigators tracked cognitive impairment using the Mini-Mental State Examination and categorized physical activity via self-reports. Sedentary behavior at baseline was significantly associated with cognitive impairment between ages 78 and 85 (OR 2.61) and ages 85 and 90 (OR 2.90). A similar association between ages 90 and 95 was not statistically significant. The proportion of physically active participants peaked at 77.0% at age 78, dropped to 16.0% at age 90, and was 27.1% at age 100.
Why it matters
Determining whether lifestyle habits continue to influence brain health beyond age 80 clarifies how long behavioral interventions remain relevant in late-life cognitive aging. The findings suggest that physical activity remains associated with cognitive protection into very advanced age.
Caveats
The observational design cannot establish a causal relationship between exercise levels and cognitive outcomes. In addition, physical activity was self-reported, and the association was not statistically significant for the interval between ages 90 and 95.
The paper
Hadassah Medical Center
Journal of Alzheimer's Disease · 28 Sep 2026