Colter Mitchell and colleagues found that 9-year olds growing up in highly disadvantaged environments had shorter telomeres than their highly advantaged counterparts, with genetic sensitivity having a moderating effect.
Disadvantaged social environments are associated with adverse health outcomes. This has been attributed, in part, to chronic stress. Telomere length (TL) has been used as a biomarker of chronic stress: TL is shorter in adults in a variety of contexts, including disadvantaged social standing and depression. Using data from 40, 9-year-old boys participating in the Fragile Families and Child Wellbeing Study, we show that those who grow up in highly disadvantaged environments have shorter telomeres than boys who grow up in highly advantaged environments. We also find that the association between the social environment and TL is moderated by genetic variation within the serotonin and dopamine pathways. Boys with the highest genetic sensitivity scores had the shortest TL when exposed to disadvantaged environments and the longest TL when exposed to advantaged environments. To our knowledge, this report is the first to document a gene–social environment interaction for TL, a biomarker of stress exposure.