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.