How is volunteering associated with reduced mortality? A mediator-wide approach.

Objective: Volunteering has been repeatedly associated with reduced mortality in older adults, yet research examining the mechanisms explaining this association remains limited. We evaluated potentially modifiable mediators, and combinations of mediators, that may underlie the volunteering-mortality association.

Method: We used prospective data from 9,962 participants in the Health and Retirement Study (2006-2018), a national, diverse, and longitudinal cohort of U.S. adults aged >50. We evaluated associations between volunteering at baseline (2008/2010), mediators at Wave 2 (2010/2012), and mortality between Waves 3 and 4 (2010-2016 for Cohort A, 2012-2018 for Cohort B).

Results: After adjusting for demographic confounders and mediators in the prebaseline wave (2006/2008), we observed evidence of mediation for those who volunteered ≥100 hr/year (vs. 0 hr/year) through combined physical health factors (proportion mediated [PM] = 49.56%, p = .004) and social factors (PM = 90.76%, p = .017) as well as through increased contact with friends (PM = 25.34%, p = .015) and helping friends/neighbors/relatives (PM = 25.12%, p = .018). However, there was less evidence of mediation through other proposed mediators.

Conclusions: With further research, these results inform basic science, interventions, and policies by identifying potential mechanisms, which might become modifiable features of the volunteering experience, to promote longevity in our rapidly aging population. (PsycInfo Database Record (c) 2025 APA, all rights reserved).