Does lifestyle matter? Individual lifestyle factors and their additive effects associated with cognitive function in older men and women.

Objectives: This study investigated the association between healthy lifestyle comprised of multiple domains, gender, and cognitive function in older Chinese people in Hong Kong. Methods: We conducted a cross-sectional analysis with data from 1,831 community-dwellers aged 65 years and above. Participants' basic demographics, comorbidity, and six lifestyle factors: diet; smoking; alcohol drinking; and physical, mental, and social activities were surveyed. Cognitive function was assessed using the Cantonese Chinese Montreal Cognitive Assessment (CC-MoCA). Linear regressions were performed to examine the associations between lifestyle, gender, and cognitive performance. Results: There were gender differences in lifestyle: men smoked (chi(2)(1) = 159.4) and drank more (chi(2)(1) = 85.9) and were more active in mentally stimulating activities (chi(2)(1) = 14.3, all p<.001); while women were more socially active (chi(2)(1) = 28.0). Age, gender and education explained the greatest variance in cognition (R-2=.32). Being active/healthy in more domains further contributed to better cognitive function, although the effect was small (Delta R-2=0.03 in women; Delta R-2=0.01 in men, both p<.05). Among the lifestyle domains, physical activity showed the strongest effects on cognitive function (Delta R-2=0.004 in men and Delta R-2=0.02 in women, both p<.05). Conclusions: Naturalistically, a physically active lifestyle and being active/healthy in more domains is associated with better cognitive function in older people after controlling for non-modifiable and early-life factors. The effects are however small. There are gender differences in lifestyle and the impact of lifestyle on cognitive function. Preventive strategies targeting lifestyle domains for cognitive health in older people may consider these naturalistic associations.