Older adults who get together with friends, volunteer, or go to classes have healthier brains, which could help them ward off dementia, according to a new study.

Researchers who used brain imaging to examine brain areas involved in mental decline found that greater social engagement made a difference in brain health.

Being socially engaged — even moderately — with at least one relative or friend activates parts of the brain needed to recognize familiar faces and emotions, make decisions, and feel rewarded, the study found.

"We need to do more research on the details, but that's the beauty of this — social engagement costs hardly anything, and we do not have to worry about side effects," said lead author Dr. Cynthia Felix, a geriatrician and postdoctoral associate at the University of Pittsburgh Graduate School of Public Health.

"There is no cure for dementia, which has tremendous costs in terms of treatment and caregiving. Preventing dementia, therefore, has to be the focus. It's the 'use it or lose it' philosophy when it comes to the brain," she said in a university news release.

The researchers drew on information from nearly 300 community-dwelling seniors (average age: 83) who had a sensitive brain scan to gauge the integrity of brain cells used for social engagement.

Once brain cells die, dementia typically follows. Researchers said it's not yet clear whether social engagement keeps brains healthy or if having a healthy brain leads to more socializing.

Either way, the findings suggest that "prescribing" socialization could benefit older adults' brain health — similar to the way prescribing physical activity can help prevent diabetes or heart disease. Existing programs that provide group physical activities would be a good starting point, Felix said.

"Our data were collected before the COVID-19 pandemic, but I believe our findings are particularly important right now, since a one-size-fits-all social isolation of all older adults may place them at risk for conditions such as dementia," she said.

"Older adults should know it is important for their brain health that they still seek out social engagement in safe and balanced ways during the pandemic," Felix advised.

The findings were reported Oct. 19 in the Journal of Gerontology: Psychological Sciences.