Lifestyle factors and risk of dementia: Dubbo Study of the elderly

Objective: To identify risk factors for dementia in an elderly Australian cohort. Design and setting: A longitudinal cohort study conducted in Dubbo, NSW. Participants: 2805 men and women aged 60 years and older living in the community and initially free of cognitive impairment, first assessed in 1988 and followed for 16 years. Main outcome measure: Admission to hospital or nursing home with any kind of dementia. Results: There were 115 cases of dementia in 1233 men (9.3/100) and 170 cases in 1572 women (10.8/100). In a proportional hazards model for dementia, any intake of alcohol predicted a 34% lower risk, and daily gardening a 36% lower risk. Daily walking predicted a 38% lower risk of dementia in men, but there was no significant prediction in women. The lowest tertile of peak expiratory flow predicted an 84% higher risk of dementia, the upper tertile of depression score predicted a 50% higher risk. Conclusion: While excess alcohol intake is to be avoided, it appears safe and reasonable to recommend the continuation of moderate alcohol intake in those already imbibing, as well as the maintenance of physical activity, especially daily gardening, in the hope of reducing the incidence of dementia in future years.