Social, demographic, and behavioral factors associated with intrinsic capacity in older Brazilians (ELSI-Brazil)

Population aging has accelerated in low- and middle-income countries, including Brazil, challenging health systems traditionally focused on disease-centered care. In this context, the World Health Organization proposed intrinsic capacity (IC), the composite of physical and mental capacities, as a core construct for healthy aging. Evidence from developing countries remains limited, particularly regarding sex differences. Aging trajectories differ between women and men due to biological and socially constructed inequalities that accumulate across the life course in Brazil. This study estimated the prevalence of intrinsic capacity and associated factors among older adults in Brazil, considering sex differences. Data from the second wave of the Brazilian Longitudinal Study of Aging (ELSI-Brazil) were used to assess adults aged ≥ 50 years across five IC domains: locomotion, cognition, vitality, sensory, and psychological. Preserved IC was defined using a composite score. Sex-stratified multivariable regression analyses were conducted to identify associated factors. The overall prevalence of preserved IC was 73.0% (95% CI 68.7–77.0), with men showing lower impairment across domains. In both sexes, younger age, higher education, and regular physical activity were positively associated with preserved IC. Among women, higher income, moderate alcohol consumption, non-smoking, and regular intake of fruits, vegetables, and legumes were additional protective factors. Among men, living with a spouse or partner was independently associated with preserved IC. Sex differences in intrinsic capacity highlight the need for targeted interventions and policies to promote healthy aging throughout the life course in Brazil. Sex-specific strategies—including dietary counseling for women, social support for men, and physical activity promotion for both sexes—are essential to preserve IC.