Associations between self-reported change in lifestyle behaviors and brain health: Findings from the Healthy Brain Initiative

Background Healthy lifestyles may reduce dementia risk by helping build cognitive reserve across the life course and promoting resilience and better cognitive outcomes in late-life. Whether self-reported lifestyle changes are informative for assessing brain health remains unclear. Objective To determine whether self-reported lifestyle changes (determinants) are associated with cognition, resilience, and Alzheimer's disease and related dementias (ADRD) biomarkers (outcomes), and whether these associations vary by sociodemographic characteristics and cognitive impairment status. Methods Data was obtained from 260 adults (age-range: 50–92). Self-reported change (increase/no change, decrease) in diet and physical, cognitive, and social activity from age 25 to present was evaluated in relation to cognition, resilience, and biomarkers within a cross-sectional design. ANCOVA models adjusted for age, sex, race, ethnicity, and education were used to examine associations between lifestyle change and outcomes. Effect modification by sex, race, ethnicity, and cognitive impairment status was also tested. Results Self-reported increases in physical activity and diet were associated with better cognition and higher resilience, while increases in social activity with higher resilience and larger amygdala volume. Associations were stronger when increases occurred in multiple lifestyle domains. Associations differed by cognitive impairment status; no variation by sex and race was observed. Conclusions Increases in lifestyle behaviors relative to age 25 were associated with better cognitive and brain health outcomes, especially when increases occurred across multiple domains. These findings align with longitudinal evidence linking lifestyle engagement to cognitive aging and suggest that cross-sectional self-report of change may provide a useful proxy for estimating long-term lifestyle patterns.