Healthy dietary patterns may influence biological aging, but prospective evidence for the MediterraneanDASH Intervention for Neurodegenerative Delay (MIND) diet is limited. We linked 2013 dietary data to 2016 DNA methylation measures in 1,740 Health and Retirement Study participants. Per 1-s.d. higher MIND score, adjusted differences were -0.4 years for PhenoAge acceleration (95% CI -0.8 to -0.1), -0.3 years for GrimAge acceleration (-0.5 to -0.1) and -0.0054 for methylation Pace of Aging (-0.0098 to -0.0010); all false-discovery-rate q[≤]0.026. Associations persisted after body-mass-index adjustment and selection weighting. Targeted maximum likelihood estimates were concordant with the conventional models, whereas causal forests evaluated in held-out and repeated-split samples found no reproducible evidence that specific subgroups of participants benefited more than others. Greater MIND adherence was associated with lower subsequent epigenetic aging across complementary measures, supporting molecular aging as an intermediate phenotype for diet-aging research.