May 9 --

FRIDAY, May 8 (HealthDay News) -- Volunteering your time doesn't just help others; it turns out, it probably benefits your health, too.

Retirees over 65 who volunteered had less than half the risk of dying compared to their non-volunteering peers, according to a study presented May 2 at the American Geriatrics Society annual meeting, in Chicago.

"We found that volunteering remains a powerful predictor of decreased mortality among current U.S. retirees, even after extensive adjustment for possible confounding factors," wrote the study's authors.

Although previous research has already shown an improvement in mortality rates among people who volunteer, the authors noted that past research has focused on people born before 1920, and that those studies haven't adjusted for all of the potential variables, such as socioeconomic status or chronic health conditions. One argument that people have made is that older people who are volunteering are likely healthier than those who choose not to volunteer, and that's one of the many possible confounding factors the current study tried to address.

"Our research was building on what other people have previously done. A concern with past studies is that volunteers may be healthier to begin with. We thought we could account for this and other factors that could confound the relationship, and even after we examined those other factors, volunteers still had lower mortality," said the study's lead author, Dr. Sei Lee, an assistant professor of geriatrics at the University of California, San Francisco, and the San Francisco VA Medical Center.

However, Lee pointed out that this study's findings are preliminary and said his research is ongoing.

The study included 6,360 retired people over 65 years of age who were enrolled in the Health and Retirement Study (HRS) in 2002. This study population is considered representative of older adults in the United States. The average age in the study was 78, and the study population was 60 percent female.

Whether or not the study participants volunteered was assessed by asking, "Have you spent any time in the past 12 months doing volunteer work for religious, educational, health-related or other charitable organizations?"

The researchers controlled the data to account for demographics, socioeconomic status, chronic health conditions, geriatric syndromes, functional limitations, a subject's propensity for volunteering, depression, cognition and self-rated health.

In this initial assessment, the researchers found that 12 percent of the 1,766 volunteers in the study died compared to 26 percent of the non-volunteers. After adjusting the data, the researchers said the association between volunteering and a lower risk of mortality wasn't as strong, but that it still existed.

Lee said that although they didn't study the reasons for the apparent benefit of volunteering, other researchers have, and that several factors likely play a role. One may be that volunteers have a better social network, which has been associated with lower mortality. He said that volunteering also seems to be associated with "self-efficacy" or a belief in your own abilities to accomplish certain tasks. "Staying healthy requires doing different things like quitting smoking or losing weight," explained Lee, and people who have higher self-efficacy may believe themselves more capable of accomplishing those tasks.

"This is another component of a long line of work that suggests you want to remain engaged in life, and be active in as many domains as possible. Be physically active, mentally active and socially active. These are really important for staying as healthy as possible for as long as possible," said Lee.

"People who are socially engaged will have a better quality of life and better survival," said Dr. Gary Kennedy, director of the division of geriatric psychiatry at Montefiore Medical Center in New York City. "This study is a good way of using science to reinforce what's good common sense. Volunteering is a good thing to do, and lo and behold, it's good for you, too."

More information

Learn more about the benefits of volunteering at NationalService.gov.

SOURCES: Sei Lee, M.D., assistant professor, medicine, geriatrics, University of California, San Francisco; Gary Kennedy, M.D., director, division of geriatric psychiatry, Montefiore Medical Center, New York City; May 2, 2009, presentation, American Geriatrics Society annual meeting, Chicago