Plant-based dietary patterns are associated with slower epigenetic aging.

Greater adherence to plant-based diets is associated with health benefits. Dietary intake can modify DNA methylation patterns, but it is unknown whether plant-based diets in a largely non-vegetarian population are associated with DNA methylation-based epigenetic aging measures. We examined the associations between 4 different types of plant-based diets indices (PDI) [overall PDI, provegetarian diet, healthy PDI, and unhealthy PDI] and epigenetic aging. We used data from the Atherosclerosis Risk in Communities (ARIC) Study (N=2,810) and National Health and Nutrition Examination Survey (NHANES, N=2,056). PDIs negatively scored higher intake of animal products and positively scored higher intake of all or selected plant foods (overall PDI and provegetarian diet), healthy plant foods (healthy PDI), and unhealthy plant foods (unhealthy PDI). Associations were examined with GrimAge version2, HannumAge, and PhenoAge in each study. Estimates were meta-analyzed using fixed effects model. Each standard deviation (SD) higher in the overall PDI, provegetarian diet, and healthy PDI was associated with decelerated GrimAge2 (range of <i>β</i> = -0.28 to -0.16, P for all tests <0.05). Higher overall PDI and provegetarian diet was associated with decelerated PhenoAge and HannumAge (overall PDI only). No significant association was observed for unhealthy PDI. Following diets rich in plant foods and low in animal products may slow biological aging.