To explore the underlying dimensions of a set of interrelated lifestyle factors and test the hypothesis that an active lifestyle may protect against dementia.
The study population consisted of 776 participants aged >or=75 years who were dementia-free at both baseline and the first follow-up examinations. Participation in leisure activities was assessed at baseline of the survey, and principal component analysis was used to identify their underlying factors.
During the 9-year follow-up from exposure assessment, 212 subjects developed dementia. Higher factor scores of physical, mental, and social dimensions of an active lifestyle was each related to a lower dementia risk. A significant dose-response association between participation in the diverse dimensions and lower dementia risk was observed.
An active lifestyle may protect older people against dementia, and the higher level of engagement the stronger protection.