Abstract
BACKGROUND: Caring for sick or disabled relatives is a key model for understanding the effects of chronic stress on immunity/inflammation; biomarkers which are part of an index of allostatic load. Here, we examine whether caring and allostatic load are predictive of future illness/disability and if the association between caring and illness/disability is mediated by allostatic load. METHOD: Using data from the Understanding Society Wave 2 (2011) and Wave 9 (2017-2019) datasets in the UK, a sample of 471 of caregivers and 2,151 non-caregivers (all initially healthy) were compared on allostatic load and future illness/disability. RESULTS: Caregivers had higher allostatic risk scores, for total as well as immune and non-immune biomarkers, and were more likely (23.3% vs 17.4%) to have an illness/disability in the future compared to non-caregivers. Moreover, caregiving was responsible for a 33% future illness/disability risk. Further, allostatic load was also predictive of excess risk (OR = 1.18, 95% CI = 1.08 - 1.26; p < .001); higher allostatic load was associated with increased risk of illness/disability in the future. In an unadjusted mediation model, allostatic load mediated the association between caregiving and future illness/disability. However, after controlling for confounding, the mediation became non-significant. CONCLUSIONS: These results confirm that caregiving and allostatic load are damaging for future health. Results are also discussed in relation to public health aspects of caregiving.