Wealth, Epigenetic Age Acceleration, and Intrinsic Capacity: A Multidomain Mediation Analysis

Objectives Socioeconomic disadvantage is associated with poorer health outcomes, yet the mechanisms remain incompletely understood. This study examined whether GrimAge epigenetic age acceleration (EAA) mediates the association between wealth and intrinsic capacity (IC). Methods We analyzed 1,143 Health and Retirement Study participants with temporally ordered measures of wealth, GrimAge EAA, and IC. Linear regression models assessed associations between GrimAge EAA and age-adjusted IC. Mediation of the wealth–IC association by GrimAge EAA was evaluated using natural effect models. Uncertainty was estimated via bootstrap. Results Higher GrimAge EAA was consistently associated with lower IC across domains. Natural effect models indicated partial mediation of the wealth–IC association by GrimAge EAA for psychology (12.5%), locomotion (11.1%), vitality (33.3%), and the composite score (10.8%). Conclusion Our findings support biological aging as one pathway through which wealth influences functional outcomes in later life, while suggesting that no single biomarker fully captures wealth-related functional decline.