Abstract
Objective: Emerging literature suggests later life adversity increases susceptibility to cognitive disorders, whereas structural support (defined here as social networks/contacts) and life satisfaction benefit cognitive health. However, evidence for these associations remains limited in low- and middle-income countries. To address this gap, the present study examined the associations of later life adverse (recent stressful events, neighborhood disadvantages, and multimorbidity) and favorable (structural support and life satisfaction) factors with cognitive outcomes in Brazil.
Method: This population-based study utilized a nationally representative sample of 6,564 adults aged 50 and over, drawn from the Brazilian Longitudinal Study of Aging. Survey-weighted generalized linear models characterized the association of each relevant factor with cognitive performance, assessed through a global composite score derived from performance on tasks designed to measure temporal orientation, immediate and delayed memory recall, semantic fluency, and prospective memory. Two-way interaction models tested whether sex, race, or household income extreme quintiles modified significant associations.
Results: In the multivariable model, greater structural support (0.030, 95% CI [0.021, 0.040]) and life satisfaction (0.014, 95% CI [0.008, 0.019]) were strongly associated with better cognitive function, independent of demographic characteristics and the adverse factors investigated. Notably, the protective association of structural support on cognition was twice as strong among individuals self-identified as Black/Brown (0.039, 95% CI [0.025, 0.052]) compared to White participants (0.019, 95% CI [0.007, 0.032]) and over 2.5 times stronger for individuals in the lowest household income quintile (0.048, 95% CI [0.028, 0.069]) relative to those in the highest quintile (0.018, 95% CI [0.000, 0.035]). Among adverse experiences, only recent severe illness (-0.057, 95% CI [-0.090, -0.023]) was significantly associated with poorer cognition, potentially reflecting a combination of biological and psychosocial mechanisms.
Conclusions: Public health initiatives should prioritize building community-based support structures and endeavor to target Black/Brown and socioeconomically disadvantaged communities while addressing factors that contribute to life satisfaction in later adulthood.