July 8, 2008
Men and women who remain socially connected with friends and family as they age appear to have sharper memories, a new study shows. The findings, from the Harvard School of Public Health, add to a growing body of evidence that active social engagement is key to keeping the brain fit and lowering the risk of Alzheimer's among the elderly.
"We hope this study adds to and advances our growing understanding of the important role that social forces play in shaping health," said Karen Ertel, postdoctoral fellow in the department of society, human development and health at the school. Currently, up to 10 percent of Americans over 65 suffer from some form of serious memory loss.
In the study, published in the American Journal of Public Health, researchers analyzed data gathered from 1998 to 2004 as part of the Health and Retirement Study, a large, nationally representative population of American adults age 50 and older.
Every two years, study participants in their 50s and 60s were given a simple memory test. Researchers read to them a lit of 10 common nouns, then asked them to recall however many they could remember immediately after the words were read and again five minutes later. They were also asked about their marital status, whether they participated in volunteer activities, and how much daily contact they had with family members, friends and neighbors.
The researchers found that men and women who had the most social interaction within their community had the slowest rate of memory decline. Indeed, those who had the most contact with friends, family apeople in their neighborhood had less than half the rate of memory loss as those with the least social engagement.
The findings were independent of social and demographic factors like age, gender and race as well as overall health status. And the benefits appear to have been most pronounced in those who had fewer than 12 years of formal schooling. Earlier research has shown that lack of education is a risk factor for Alzheimer's disease.
Some research has suggested that Alzheimer's may be a long, even decades-long process, and that symptoms like social withdrawal may be an early indicator of brain problems. However, in the current study, the researchers found no evidence that the results were due to poor memory or memory decline causing social withdrawal.
"Social participation and integration have profound effects on health and well being of people during their lifetimes," said Lisa Berkman, senior author of the report. "We know from previous studies that people with many social ties have lower mortality rates. We now have mounting evidence that strong social networks can help to prevent declines in memory. As our society ages and has more and more older people, it will be important to promote their engagement in social and community life to maintain their well being."
"We need to understand more about how social integration reduces the risk of memory decline in order to target interventions that can help slow the decline," Dr. Ertel added. "Future research should focus on identifying the specific aspects of social integration most important for preserving memory."
Support for the study was provided by the National Institute of Aging.
Karen A. Ertel, M. Maria Glymour, Lisa F. Berkman: "Effects of Social Integration on Preserving Memory Function in a Nationally Representative U.S. Elderly Population." American Journal of Public Health, July 2008, Vol. 98, No. 7.