Masticatory ability and active aging: Uncovering a structural pathway mediated by depression

BACKGROUND: Masticatory ability is closely linked to physical health, psychosocial well-being, and social participation in later life, yet its role in active aging remains underexplored. This study examined the longitudinal association between masticatory ability and the Active Aging Index (AAI), focusing on the mediating role of depression. METHODS: Using nationally representative longitudinal panel data from the Korean Longitudinal Study of Ageing (2006-2022), we conducted an observational study of 8210 older adults (13,841 observations) in South Korea. Ordinary least squares (OLS) regression and structural equation modeling (path analysis) were used to estimate direct and indirect effects. Masticatory ability was conceptualized as a need factor, depression as a psychosocial mediator, and Active Aging Index as a multidimensional aging outcome. The primary outcome was the Active Aging Index, a composite measure capturing health, social participation, and socioeconomic security. RESULTS: The mean age of participants was 61.71 years, and 56.48 % were female. Higher masticatory ability was significantly associated with higher Active Aging Index scores (β = 0.0245, 95 % CI: 0.022-0.027, p < 0.001). Path analysis showed a direct effect (β = 0.01917, p < 0.001) and an indirect effect via depression (β = 0.00537, p < 0.001). Higher masticatory ability was associated with lower depressive symptoms, which were in turn associated with higher Active Aging Index. CONCLUSION: Masticatory ability was positively associated with active aging, with depression partially mediating this relationship among older adults. These findings highlight the role of oral function in both psychological well-being and broader aspects of aging.