Leisure Exercise Linked to Lower Dementia Risk: Study
USA: A large systematic review and meta-analysis involving more than 4.2 million people has found that leisure-time physical activity was associated with a lower risk of dementia. In contrast, occupational physical activity was linked to a higher dementia risk. Researchers suggested that physically demanding jobs may reflect broader social, occupational, and brain health risks, highlighting that the health benefits of exercise may vary depending on the context in which physical activity occurs.
The study, published in The Lancet Public Health by Natan Feter, PhD, Human and Evolutionary Biology Section, Department of Biological Sciences, University of Southern California, Los Angeles, and colleagues, examined whether the relationship between physical activity and dementia differed according to where and how the activity was performed.
The researchers conducted a systematic review and meta-analysis of cohort and case–control studies identified through PubMed, CINAHL, Scopus, PsycINFO, SPORTDiscus and Web of Science. Studies published through May 2, 2026, were considered, along with studies from an earlier systematic review.
Among 6,270 records initially identified, 17 new studies met the eligibility criteria. Together with 57 studies from the previous review, the analysis included 74 studies involving 4,227,297 participants from 30 countries. Participants had a median age of 67.3 years and were followed for a median of 10 years.
Overall, higher levels of physical activity were associated with lower risks of dementia. The researchers reported:
- 20% lower risk of all-cause dementia among people with higher physical activity levels.
- 21% lower risk of Alzheimer's disease.
- 29% lower risk of vascular dementia.
- Leisure-time physical activity was associated with a 24% lower risk of all-cause dementia.
- Household physical activity was also associated with a modestly reduced dementia risk.
- In contrast, occupational physical activity was associated with a 20% higher risk of all-cause dementia.
- Commuting-related physical activity was associated with a 10% higher risk.
The findings suggest that where and how physical activity is performed may influence dementia risk. Leisure-time exercise may offer benefits through recreation, social engagement and recovery, while physically demanding jobs may also involve stress, socioeconomic disadvantage, hazardous conditions and inadequate rest. However, the mechanisms behind these differing associations remain unclear, and occupational activity itself cannot be considered a direct cause of dementia.
The study had several limitations, including reliance on self-reported physical activity, limited evidence on household and commuting activity, and the observational nature of the included studies, which leaves the possibility of reverse causation and residual confounding.
Notably, 69 of the 74 studies were conducted in high-income countries, highlighting limited evidence from low- and middle-income regions where dementia rates are expected to increase substantially.
The researchers emphasized that dementia prevention strategies should consider the context of physical activity, while promoting equitable access to safe leisure-time exercise and reducing potential health risks linked to physically demanding occupations.
Reference:
Feter N, Iso-Markku P, Markarian T et al. Domain-specific physical activity levels and risk of dementia: a systematic review and meta-analysis. The Lancet Public Health, 11, e650-e664
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