- Physical activity: ≥150 minutes/week was associated with a 25% lower dementia risk (RR 0.75, 95% CI 0.68–0.82), though heterogeneity was high (I²=92.5%).
- Sedentary behavior: ≥8 hours/day of sitting was linked to a 27% higher risk (RR 1.27, 95% CI 1.17–1.39), but evidence is limited to 3 studies, most with serious bias.
- Sleep duration: Both short (<7 h) (RR 1.18) and long (>8 h) sleep (RR 1.28) were associated with increased risk compared with 7–8 hours.
- Midlife relevance: Benefits of physical activity may be less pronounced in older adults with long follow-up, suggesting earlier-life exposure may matter more.
- Interpretation caution: Observational design, confounding, and bias preclude causal inference, and results should be interpreted as associations only.
Daily News
Stay up to date with the latest clinical headlines and other information tailored to your specialty.
