Parental education and epigenetic aging in middle-aged and older adults in the United States: A life course perspective

Epigenetic aging is one plausible mechanism by which socioeconomic status (SES) contributes to disparities in morbidity and mortality. Although the association between SES and epigenetic aging is well documented, the role of parental education into adulthood remains understudied. We examined (1) if parental education was independently associated with epigenetic aging, (2) whether upward educational mobility buffered this association, and (3) if the benefit of parental education was differentiated by race/ethnicity. Secondary data analysis of a subsample (n = 3875) of Non-Hispanic [NH] Black, Hispanic, NH White, and NH other race participants from the Venous Blood Study within Health and Retirement Study were examined. Thirteen clocks based on DNA methylation of cytosine-phosphate-guanine sites were used to calculate epigenetic aging. Participants' education (personal) and their report of their respective parent's education (parental; mother's and/or father's) were included as independent variables; several potential confounders were also included. Direct associations and interactions between parental and personal education were estimated via survey-weighted generalized linear models; marginal means for epigenetic aging were estimated and contrasts were made between the education subcategories. Analyses were also stratified by race/ethnicity. Our results showed that higher parental education was independently associated with slower epigenetic aging among four clocks, whereas higher personal education magnified this association among four different epigenetic clocks. Participants with the lowest parental and personal education had higher marginal means (i.e., accelerated aging) compared to participants with the highest parental and personal education, and there was little evidence of upward mobility. These associations were more frequently observed among NH White participants, whereas fewer were observed for Hispanic and NH Black participants. Overall, our findings support that early-life circumstances may be biologically embedded through epigenetic aging, which may also limit the biological benefits associated with one's own education.