REVIEW OF: Su S et al, Neurology 2022;99(15):e1651–1663.

STUDY TYPE: Meta-analysis of longitudinal cohort studies

When patients ask us what they can do to lower their risk of dementia, we often recommend exercise or eating a healthy diet. This study looks at dementia prevention from another angle—how patients spend their free time.

This meta-analysis reviewed 38 studies from around the world and included more than two million participants without dementia with a mean age of 45-93 years at baseline. Participants were followed for at least three years and completed questionnaires and interviews about their leisure activities. Leisure activities were defined as activities participants engaged in for well-being or enjoyment and were separated into cognitive, physical, and social activities. Cognitive activities included crossword puzzles, reading books, and writing for pleasure. Physical activities included yoga, hiking, running, and dancing. Social activities included going to a center and meeting with friends or relatives.

The authors found that participants who engaged in leisure activities had a 17% lower risk of developing all-cause dementia (ACD) compared to participants who did not engage in leisure activities. Participants who engaged in cognitive activities had a 23% lower risk, those who engaged in physical activities had a 17% lower risk, and those who participated in social activities had a 7% lower risk. Physical and cognitive pursuits were related to a reduced risk of Alzheimer’s disease (13% and 34%, respectively), and physical activity was also associated with a 33% reduced risk of vascular dementia.

Although the authors attempted to address systematic differences between studies, there was a considerable amount of heterogeneity between the meta-analyzed studies. Additionally, the studies looked at self-reported behavior, which is often unreliable.

CARLAT TAKE 

As is true for any observational study, these findings can only show that a correlation exists between certain activities and a lower rate of dementia. Whether this correlation implies that these activities actually reduce dementia risk is unknown. Nonetheless, being active in old age has many other benefits on a patient’s body and mood, so we can encourage our patients to spend time on any activities that bring them joy.