Socializing with friends and family can do more than lift the spirits of elderly women - it can improve cognition and might help prevent dementia, according to a study.

The study began in 2001 and included women at least 78 years old who were free of signs of dementia. Researchers conducted follow-up interviews between 2002 and 2005 (American Journal of Public Health, July 2008).

"We've interviewed people who were not demented and who were able to report on their social network at baseline in 2001," said lead author Valerie Crooks, DSW, director of clinical trials administration and a research scientist at the Southern California Permanente Medical Group. "By starting with people who are cognitively intact and following them over time, you can begin to make a legitimate link between social networks and dementia."

Women frequently experience increasing social isolation as they age, but it has been difficult to make a solid connection between this social separation and cognitive function and dementia.

For this study, researchers pooled data from 2,249 members of a health maintenance organization, comparing health conditions and demographic information for women with and without dementia at follow-up, at which time they identified 268 new dementia cases in the previously screened women.

The researchers rated each woman's social network by asking about the number of friends and family members who kept in regular contact, and of these, how many she felt she could rely on for help or confide in.

Of the 456 women with low "social network" scores, 80 women (18 percent) had developed dementia. Of the 1793 women with stronger social networks, 188 (10 percent) had developed dementia.

"The study does a laudatory job of addressing the relationship of these variables," said Deborah Newquist, PhD, director of geriatric services at Louisville, Ky.-based ResCare, Inc. However, concluding that isolation causes dementia might be overstating the case, said Dr. Newquist, who is not associated with the study.

"The fundamental problem here is one of the chicken and the egg," she said. "Are weak social relationships caused by dementia or the other way around?"

"Finding ways to help older adults remain engaged in productive and enjoyable activities is an important component of successful aging," said Cathleen Connell, PhD, head researcher at the Center for Managing Chronic Disease at the University of Michigan. "Not only have social networks been linked to positive physical and mental health outcomes, but also to quality of life."

"Our findings indicate that it's important to think about ways to try to reduce the amount of isolation people have - even those with families," Dr. Crooks said. "It's also important for us to find out what kinds of social support groups we can create for people who are isolated based on extreme age or lack of family."