It's a wonderful irony of volunteering that helping others seems to promote your own health and wellbeing. While dedicated volunteers may not need empirical evidence that they reap longevity benefits themselves, there's mounting research showing this is in fact the case.
A 2013 report published in the journal Psychology and Aging set out to analyze a number of previous studies on the health benefits of volunteerism, the first meta-analysis to do so. Researchers from Arizona State University and the University of Michigan cite past research in which subjects found volunteering boosted their satisfaction in relationships, and reduced their stress levels. In addition, subjects who'd suffered the death of a spouse were found to recover faster from depression when they volunteered. Finally, both mortality and morbidity (illness) were each reduced among caregivers helping others in separate studies.
Led by Morris Okun, a psychology professor at Arizona State University, the meta-analysis examined a total of 14 studies published over a 25-year period on the health effects of volunteering. Only studies involving so-called "organizational" volunteering — helping in an activity that provides services to an individual or the community without pay — were included, to assess how volunteering affects mortality risk.
Volunteering tasks involving family members (caregiving) and informal social activities were excluded from the review, in order to assess the longevity benefits of volunteering for people unrelated to the subjects themselves. Likewise, studies involving subjects younger than 55 years were also excluded. The researchers explain that factors like lower stress from volunteering would only affect mortality later in life. By focusing on older adults, the review could also examine how volunteering might influence coping with the life transitions that occur with aging such as changing professional, social and family roles.
Finally, only studies assessing volunteering at the beginning of the trial period, and those measuring mortality as a possible outcome, were included.
What they found: This meta-analysis seems to confirm a strong link between volunteering and greater longevity. Among the majority (11) of the 14 studies included in the review, volunteering appeared to reduce mortality risk by almost 50%, before other confounding variables like age and gender were considered. The researchers then adjusted the mortality risk in each study allowing for additional factors like age, sex, marital status, religious beliefs, health behaviors and social connection, income, health status and physical health behaviors. Still, the benefits of volunteering appeared to be profound, yielding a 25% lower risk of death during the study periods.
How does volunteering help you live longer? Okun's team points out that a causal mechanism cannot be established from the studies currently conducted on volunteering; thus, their review does not prove that volunteering prevents death. Rather, it shows an association between organizational volunteering and decreased mortality.
Theories about why volunteering may promote longevity include better stress management among volunteers, and physiological effects like greater oxytocin and progesterone production, both associated with regulating stress and lowering levels of inflammation in the body.
According to evolutionary biology, humans may be hard-wired to help each other for their own sake, because such "pro-social" behavior benefits all members of a group or society.
There are two main and opposing views about how this might occur through volunteering behavior: the compensatory hypothesis suggests volunteering offers older adults an important role as other familiar life roles disappear with age (in effect, compensating for those losses). According to the complementary hypothesis, volunteering adds to or complements the health benefits of derived from other behaviors, such as increased satisfaction from both volunteering and attending church.
While Okun's team says it cannot draw conclusions about either theory from their review, it writes that in studies involving religious adherence and volunteering, a greater longevity effect was consistently found. This result more strongly supports the complementary theory.
What if you're only volunteering to boost your own longevity? It appears that volunteering with a selfish motive is not of benefit; a 2012 study published in the journal Health Psychology found that people who volunteer to benefit their own health do not live longer than non-volunteers.
How much volunteering is enough, or too much? Okun's team laments that the current body of research on volunteering and mortality risk is not consistent enough on the questions of how much volunteering, or how often a person volunteers, to arrive at a beneficial "dose" of helping activity. They do, however, cite research suggesting that for some volunteers, the curve is not linear — that is, volunteering up to a certain point is healthy for the volunteer, but not once the activity exceeds the resources (emotional or physical) of the person volunteering.
Bottom line: Volunteering, as many dedicated volunteers will tell you, often provides more satisfaction and pride for the helper than the recipient. Future research will assess the amount of volunteering that elicits this effect. Most likely though, as long as you can manage the activity and choose a cause that moves you, you will know how much and how often you need to volunteer, to boost your own health and well-being.
Konrath, S., Fuhrel-Forbis, A., Lou, A., & Brown, S. (2012). "Motives for volunteering are associated with mortality risk in older adults." Health Psychology, 31, 87–96.
Okun, M. A., Yeung, E. W., & Brown, S. (2013). "Volunteering by older adults and risk of mortality: A meta-analysis." Psychology and Aging, 28(2), 564-577. doi:10.1037/a0031519
Sneed, Rodlescia S.; Cohen, Sheldon. "A prospective study of volunteerism and hypertension risk in older adults." Psychology and Aging, Vol 28(2), Jun 2013, 578-586.