Many retirees opt to volunteer as a way to help others, but new research suggests this act can also benefit volunteers' brain health.

Volunteering later in life may provide protection for the brain from both cognitive (mental) decline and dementia, according to researchers. Their findings were presented this week at the Alzheimer's Association International Conference, in Amsterdam, in the Netherlands.

Older adults who volunteered had better memory and executive function than their peers who did not engage in these acts of service.

"Volunteers are cornerstones of all communities and imperative to the success and impact of many organizations, including the Alzheimer's Association," said Donna McCullough, Alzheimer's Association chief mission and field operations officer.

"We hope these new data encourage individuals of all ages and backgrounds to engage in local volunteering -- not only to benefit their communities, but potentially their own cognitive and brain health," she said in an association news release.

Supporting educational, religious, health-related and other charities offers people a variety of benefits. These include a chance to be more physically active, increased opportunities for social interaction and mental stimulation.

For the study, researchers looked at volunteering habits among more than 2,400 ethnic and racially diverse older U.S. adults who were part of the Kaiser Healthy Aging and Diverse Life Experiences Study (KHANDLE) or the Study of Healthy Aging in African Americans (STAR). Average age was 74.

About 43% of the participants in the combined groups reported volunteering in the past year.

Study co-author Yi Lor is an epidemiology doctoral student at the University of California, Davis, and associate director of the UC Davis Alzheimer's Disease Center. Lor and his professor Rachel Whitmer found an association between volunteering and better baseline scores on tests of executive function (skills needed to get things done) and verbal episodic (memory of events or personal experiences).

The researchers also found a trend toward less cognitive decline over the follow-up time of 1.2 years, but this wasn't statistically significant. Also, seniors who volunteered several times a week had the highest levels of executive function.

"Volunteering may be important for better cognition in late life and could serve as a simple intervention in all older adults to protect against risk for Alzheimer's disease and associated dementias," Lor said in the release. "Our next steps are to examine whether volunteering is protective against cognitive impairment, and how physical and mental health may impact this relationship."

Findings presented at medical meetings are considered preliminary until published in a peer-reviewed journal. Also, while the study finds an association between volunteer and better brain health, it cannot prove a cause-and-effect relationship.