Abstract - Aims: This study was designed to assess links between lifetime levels of marijuana use and accelerated epigenetic aging.
Design: Prospective longitudinal study, following participants annually from age 13 to age 30.
Findings: Lifetime marijuana use predicted accelerated epigenetic aging, with effects remaining even after covarying cell counts, demographic factors and chronological age (β's = 0.32 & 0.27, p's < 0.001, 95% CI's = 0.21-0.43 & 0.16-0.39 for DNAmGrimAge and DunedinPoAm, respectively). Predictions remained after accounting for cigarette smoking (β's = 0.25 & 0.21, respectively, p's < 0.001, 95% CI's = 0.14-0.37 & 0.09-0.32 for DNAmGrimAge and DunedinPoAm, respectively). A dose-response effect was observed and there was also evidence that effects were dependent upon recency of use. Effects of marijuana use appeared to be fully mediated by hypomethylation of a site linked to effects of hydrocarbon inhalation (cg05575921).
Conclusions: Marijuana use predicted epigenetic changes linked to accelerated aging, with evidence suggesting that effects may be primarily due to hydrocarbon inhalation among marijuana smokers. Further research is warranted to explore mechanisms underlying this linkage.