Food insecurity, epigenetic age acceleration, and depression in middle-aged and older adults: a longitudinal cohort study.

BACKGROUND: Depression in middle-aged and older adults is a major contributor to disability, yet upstream social adversity remains underrecognized in prevention. We assessed whether food insecurity (FI) was associated with incident depression and depressive-symptom burden in the US Health and Retirement Study, and whether epigenetic age acceleration (EAA) mediated this association.

METHODS: FI was measured using the six-item US Department of Agriculture Food Security Survey Module. Depressive symptoms were assessed with the eight-item Center for Epidemiologic Studies Depression Scale (CES-D-8), with incident depression defined as elevated depressive symptoms using the ≥3 threshold. Associations between FI and incident depression were estimated using multivariable Cox models, and symptom trajectories were analyzed using mixed-effects models. In an epigenetic subsample ( = 1,430), 13 DNA methylation clocks were profiled. EAA was derived as age-adjusted residuals and its mediating role was assessed.

RESULTS: Among 5,547 participants included, 1,320 developed incident depression over 7.9 years. Compared with high food security, low and very low food security were associated with higher hazards [hazard ratio (HR) 1.58, 95% confidence interval (CI) 1.32-1.88; and HR 1.94, 95% CI 1.58-2.37], with evidence of a non-linear dose-response and an estimated 9% of incident cases attributable to FI. FI was also associated with a higher depressive-symptom burden (β = 0.72 and 1.59; both < 0.001). Zhang AgeAccel accounted for a small proportion of this association, explaining 5.3% of the total effect.

CONCLUSIONS: Food insecurity was associated with higher depression risk and sustained depressive-symptom burden in middle-aged and older adults. EAA accounted for a small proportion of this association.