Volunteering, chronic stress, and systemic inflammation among middle-aged and older adults.

BACKGROUND: Although there is a strong theoretical foundation suggesting that prosocial behaviors, such as formal volunteering, can reduce systemic inflammation, empirical support for this link is limited and the potential stress-buffering effect of volunteering remains under-studied. This study aims to address these gaps by examining the relationships between volunteering, chronic stress, and systemic inflammation, measured by C-reactive protein (CRP). In doing so, we conducted distributional analysis to analyze CRP which allowed for identifying subgroups within the population that might benefit most from volunteering.

METHODS: We used longitudinal data from the nationally representative Health and Retirement Study (N = 7994). Unconditional quantile regression (UQR) models were employed to 1) examine whether volunteering was directly associated with CRP and to 2) investigate whether volunteering buffered the negative effects of chronic stress on CRP across different levels of inflammation.

RESULTS: The results did not provide any evidence that volunteering was directly linked to CRP. However, volunteering buffered the adverse relationship between chronic stress and inflammation at higher CRP levels, with the stress-buffering effects becoming progressively greater in magnitude toward the upper end of the CRP distribution.

CONCLUSIONS: This study is the first to identify the stress-buffering effects of volunteering on inflammation using longitudinal data from a nationally representative sample. Our findings from UQR models uncovered unique evidence that the stress-buffering effects may be particularly potent at higher CRP levels, which has important implications for individuals at greater risk of inflammation-related health issues.