Volunteering might actually be good for your health, according to a review and analysis conducted by the University of Exeter Medical School. Researchers gathered and analyzed data from several different experimental trials and longitudinal cohort studies and found that volunteering could potentially improve mental health and help you live longer.

Observational evidence points to about a 20 percent reduction in mortality among volunteers compared to non-volunteers in cohort studies that were reviewed. Volunteers also reported lower levels of depression, increased satisfaction with life and enhanced feelings of well being. However, these findings have not yet been confirmed through trials.

Worldwide, adult volunteering varies an estimated 22.5 percent in Europe, 36 percent in Australia and 27 percent in the United States. Volunteers often cite “giving something back” or supporting an organization that has supported them for the reason behind their volunteering habits. Volunteering can also be used as a way to gain valuable work experience or widen your social circle, but it appears it has effects that go much deeper than just that.

Previous reviews have highlighted possible health benefits, including an increase in longevity, better quality of life and reduced stress and hospitalization. However, those benefits tend to be based on narrative rather than comparative evidence. Researchers pooled data  from 40 papers that reported on nine experimental trials and 16 cohort studies to arrive at their conclusion.

The review was led by Dr. Suzanne Richards from the University of Exeter Medical School and received support from the National Institute for Health Research Collaboration for Leadership in Applied Research and Care in the South West Peninsula (NIHRPenCLAHRC).

The underlying mechanisms behind the potential health benefits of volunteering are still unclear. Some hypothesize that physical benefits, for instance, can be explained by the fact that volunteers spend more time away from home. However the relationship with mental health benefits may be more complicated.

Dr Richards says, “Our systematic review shows that volunteering is associated with improvements in mental health, but more work is needed to establish whether volunteering is actually the cause. It is still unclear whether biological and cultural factors and social resources that are often associated with better health and survival are also associated with a willingness to volunteer in the first place. The challenge now is to encourage people from more diverse backgrounds to take up volunteering, and then to measure whether improvements arise for them.”

The study can be viewed in the open access journal BMC Public Health.