Across six harmonized longitudinal aging cohorts totaling over 23,000 adults (mean age ~65), early-life poverty—measured retrospectively for ages 10–16 using a latent construct designed to minimize recall bias—was significantly associated with elevated allostatic load (AL) in Ireland, China, and Indonesia, but not in the U.S., England, or broader Europe. AL, a composite biomarker index of cumulative physiological stress spanning cardiovascular, metabolic, and neuroendocrine systems, serves as a mechanistic bridge between social adversity and accelerated biological aging.
The finding that childhood poverty predicts higher AL decades later in some but not all nations is itself the most provocative result. It suggests that the biological embedding of early adversity is not universal but context-dependent—mediated by welfare state architecture, nutritional transitions, healthcare access, and intergenerational mobility. Ireland, China, and Indonesia share histories of rapid economic transition and historically weaker social safety nets during the study cohorts' childhoods, which may amplify physiological stress pathways. The null findings in wealthier, more-buffered systems like the U.S. and England are counterintuitive and warrant deeper investigation.
Limitations are substantial: retrospective childhood recall from older adults introduces measurement error even with latent-variable correction; cross-national AL operationalization may not be fully comparable; and as an observational study, causality cannot be established. Critically, this is a preprint posted on medRxiv and has not yet undergone peer review—findings and interpretations may change. Overall, this is a confirmatory-yet-nuanced addition to life-course epidemiology with real policy implications for child poverty reduction.
