Longitudinal Engagement in Modifiable Lifestyle Behaviors and Racial–Ethnic Differences in Dementia Risk

Objectives The objective was to examine racial–ethnic differences in longitudinal engagement for lifestyle behaviors and moderating role of race–ethnicity between lifestyle behaviors and dementia risk. Methods We analyzed 2011–2021 National Health and Aging Trends Study data, a nationally representative U.S. sample of 6155 White, Black, Hispanic, and Asian older adults aged 65+. Cox models regressed dementia on the interaction between lifestyle behaviors (physical activity, smoking, and social contacts) and race–ethnicity. Results Only smoking was associated with about a 45% higher dementia risk (aHR = 1.45, 95% CI = 1.11–1.89). On average, Black and Hispanic respondents exhibited less frequent physical activity and social contacts, along with more frequent smoking. There was one significant interaction; more social contacts were associated with lower dementia risk among Asian respondents (aHR = 0.16, 95% CI = 0.05–0.55). Discussion Racial–ethnic differences in lifestyle behaviors should be considered when addressing dementia disparities. Future research needs to explore the relationship between social contacts and lower dementia risk among Asian older adults.