Male youth BMI is associated with epigenetic ageing of female descendants but not blood or sperm DNA methylation

Higher male BMI at military draft age (18–24) is linked to slower epigenetic ageing (DunedinPACE) in daughters and granddaughters, but not in male descendants.

• Why it matters: Grandparental nutrition in youth is linked to sex-specific health traits across generations, but the molecular basis and whether epigenetic ageing mediates it are unclear.
• What they did: BMI, height, weight, and chest circumference from 1,013 men were matched to blood and sperm DNA methylation in descendants in the Young Finns Study (nblood = 362/421/200; nsperm = 51/98).
• The result: GA BMI showed inverse associations with daughters (beta = -0.01, p = 0.002, n = 169) and daughters’ daughters (beta = -0.01, p = 0.049, n = 126), while no robust evidence emerged linking GA anthropometrics to descendant methylation profiles.