Among 1,740 Health and Retirement Study participants, dietary data from 2013 were linked to DNA methylation clocks measured in 2016. Each 1-standard-deviation increase in MIND diet score corresponded to 0.4 fewer years of PhenoAge acceleration, 0.3 fewer years of GrimAge acceleration, and a modestly slower methylation Pace of Aging, all surviving false-discovery correction (q ≤ 0.026). Results held after adjusting for body mass index and reweighting for selection. Causal forests found no reproducible subgroup that benefited more.
The effect sizes are small. A third to a half year of clock difference per standard deviation of diet score is unlikely to matter for any individual, though shifts across a whole diet range could add up. Agreement across three clocks, including GrimAge, which tracks mortality risk well, adds credibility, and the null subgroup result suggests the benefit is broad rather than concentrated in particular people. Still, this is observational work: residual confounding from income, education, exercise, and smoking can inflate diet associations, and food-frequency questionnaires are noisy. Epigenetic clocks remain surrogate markers, and their link to actual lifespan or dementia in diet-driven changes is unproven. This is a preprint that has not been through peer review, so estimates may shift. Editorially, the finding is confirmatory: it extends the MIND diet's known cognitive associations to molecular aging, and fits prior Mediterranean-diet clock studies, but it does not establish causation. Emphasizing vegetables, berries, nuts, olive oil, and fish remains sound advice regardless.