Volunteering to help others doesn't only feel good -- it can also improve your mental health and help you live longer, according to a new study published Friday in the journal BMC Public Health.

In a review of 40 academic papers by the UK's University of Exeter, researchers found that volunteers had lower self-rated levels of depression and high levels of well-being and life satisfaction, although findings have yet to confirm this in trials. Volunteers were a fifth less likely to die within the next four to seven years than average.



Volunteering is thought to be especially good for the physical health of older people, by encouraging them to stay active and spend more time outside the home. But young people experience benefits as well: a separate US study published earlier this year in the journal JAMA Pediatrics linked volunteering with improved cardiovascular health in high school students.



Motives behind volunteering include wanting to "give something back" to the community, but if volunteers felt they weren't "getting something back" in return, then the positive impact was more limited, the researchers explained.



An estimated 22.5 percent of people in Europe devote some of their free time to volunteering, compared with 27 percent in America and 36 percent in Australia.



Head researcher Dr. Suzanne Richards said: "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."



A separate study from Carnegie Mellon University in the US announced in June found that volunteering can improve heart health by reducing blood pressure.