WEDNESDAY, Aug. 19, 2026 (HealthDay News) -- High physical activity is associated with reduced risks for dementia, with the associations varying by physical activity domain, according to a review published online Aug. 18 in The Lancet Public Health.Natan Feter, Ph.D., from the University of Southern California in Los Angeles, and colleagues conducted a systematic review and meta-analysis to examine the associations between domain-specific physical activity and risk for all-cause dementia, Alzheimer disease, and vascular dementia. Seventeen studies were eligible for inclusion and were combined with 57 studies from a previous systematic review, totaling 74 studies, with 4,227,297 participants.The researchers found that high physical activity levels were associated with reduced risks for all-cause dementia, Alzheimer disease, and vascular dementia during a median follow-up of 10.0 years (relative risks, 0.80, 0.79, and 0.71, respectively); associations varied by domain. A reduced risk for all-cause dementia was seen in association with leisure-time and household physical activity (relative risks, 0.76 and 0.85, respectively). In contrast, an increased risk was seen in association with occupational and commuting physical activity (relative risks, 1.20 and 1.10, respectively). Nonlinear inverse associations were seen for leisure-time and occupational activity in dose-response meta-analyses. Across domains, the certainty of evidence varied from very low to low."When it comes to protecting the brain, the context of physical activity may matter just as much as movement itself," lead author David A Raichlen, Ph.D., also from the University of Southern California, said in a statement. "Improving access to safe parks, walking trails and recreational facilities, ensuring people have adequate leisure time for exercise, and reducing harmful workplace exposures may ultimately prove as important as promoting physical activity itself."Abstract/Full Text.Sign up for our weekly HealthDay newsletter