BackgroundWhile numerous studies have documented the power of new generation epigenetic clocks to predict morbidity and mortality, research regarding the causes of variation in speed of epigenetic aging is in the early stages. To the extent that these epigenetic clocks are robust measures of biological aging, they should be sensitive to various nutritional, behavioral, ecological, and social factors that have been shown to affect health. ObjectiveInvestigate over an 11-year period the extent to which changes in socioeconomic stress and lifestyle predict changes in speed of epigenetic aging among a sample of middle-aged African American women. MethodsUsing data from the Family and Community Health Study, we investigated whether changes in socioeconomic stress, diet, smoking, exercise, alcohol consumption, and relationship status predict changes in speed of biological aging assessed with 3 s-generation epigenetic clocks: AccelGrimAge, DunedinPoAm, and AccelPhenoAge. The study was able to avoid the challenges associated with self-reports of diet and smoking by employing recently developed epigenetic measures. ResultsChanges in socioeconomic stress and diet were associated with changes in speed of biological aging as assessed by all three epigenetic clocks, and changes in smoking was related to changes in AccelGrimAge and DunedinPoAm. Analyses controlling for cell-type indicated that in large measure diet exerts its effect on aging through its impact on the immune system. ConclusionsThese findings suggest that adoption of a healthy diet and reduction in the use of tobacco are related to a decrease in epigenetic aging, whereas increased pressure relating to income, housing and economic independence are associated with an increase in the speed of aging. These effects were especially strong for the two epigenetic clocks AccelGrimAge and DunedinPoAm. Overall, the results indicate that stress and lifestyle changes may, for better or worse, influence the “biological weathering” often experienced by middle-aged African American women.