Early Poverty, Caregiving, and Adolescent Epigenetic Aging

Introduction: Socioeconomic disadvantage is associated with health disparities across the lifespan. Effective caregivers may serve to offset or buffer the impact of adversity on health. Recent research demonstrates that DNA methylation may play a key role in understanding variation in health and aging. Importantly, environmental experiences may influence DNA methylation, highlighting its potential role in serving as a biological mechanism for later health disparities. The purpose of this study was to examine the impact of early poverty and caregiving quality on later adolescent DNA methylation.

Methods: Data are from the Fragile Families and Child Wellbeing Study, a nationally-representative longitudinal study of approximately 4900 youth born in large urban cities. Participants were 370 adolescents (48% Male; 61% Black, 21% White, 14% Hispanic) with parent-child attachment security and DNA methylation data. Independent variables included poverty at birth and attachment security at age 3 using the Toddler Attachment Sort-39. The dependent variable was accelerated epigenetic aging, reflecting the change in epigenetic age from ages 9 to 15 (after removing the effect of chronological age). Salivary DNA methylation was assessed using the Infinium Methylation 450K Chip and epigenetic age was calculated using Horvath’s clock (2013).

Results: Controlling for marital status, maternal education, race/ethnicity, and adolescent gender, we find a significant interaction between poverty at birth and early attachment security (β=.28, p<.05). For children born into more advantaged environments, there was no effect of attachment on epigenetic aging (secure M=-.33, SD=2.72, insecure M=.33, SD=2.39). However, for children born at or below the poverty threshold, insecure attachment was associated with accelerated epigenetic aging (M=.56, SD=2.74). Children born into poverty with secure attachments had epigenetic age changes that were similar to children born into advantaged environments (M=.62, SD=2.58) demonstrating that secure attachment may buffer against the impact of poverty on epigenetic aging across adolescence.

Conclusions: Findings highlight the importance of high quality parenting by primary caregivers during early childhood in the context of early poverty. Prevention strategies to increase parents’ ability to provide emotional support, contingent responsiveness, and serve as a secure base during early life may promote secure parent-child attachments. Prevention aimed at building parenting capabilities during early childhood in the context of poverty may offset the impact that poverty has on adolescent health trajectories that contribute to health disparities across the lifespan.