The role of dietary patterns on epigenetic and inflammatory aging based on the INSPIRE-T study

BACKGROUND: Diet is a modifiable lifestyle factor that may modify biological aging. However, its relationship with biomarkers of biological aging is scarce or divergent. Thus, we aimed to investigate the association between dietary patterns and epigenetic and inflammatory age acceleration. METHODS: In this cross-sectional study with 764 adults (62% female; 20-100 years), participants in the INSPIRE-T observational cohort (France), we used linear regression models to associate dietary patterns (data-driven and as adherence scores to well-established diets) with biological age acceleration estimated by using epigenetic clocks (Horvath's, Hannum's, PhenoAge, and GrimAge) and the inflammatory clock (iAge). We further explored the moderating effect of sex and age groups (20-44, 45-64, ≥65), and the mediating role of body fat, measured by DXA. RESULTS: Here, we show that a 10-point increase in the Dietary Approaches to Stop Hypertension diet (DASH) score is associated with a 1.7-year lower PhenoAge acceleration, with 23% of this association being explained by android fat. Every one-unit increase in the "Plant-based" dietary pattern scores is marginally associated with 1.1-year lower PhenoAge acceleration, with total body fat accounting for 26% of this association. In the latter, the association seems more robust in older males. No consistent associations are observed for other dietary patterns, Horvath's and Hannum's clock, GrimAge, or iAge. CONCLUSIONS: Greater scores in aDASH and "Plant-based" dietary patterns are associated with lower epigenetic age acceleration through reduced body fat, with a partial moderating role of sex and age.