Two articles published in 2008 in the American Journal of Public Health suggested that a good way to help prevent dementia is to have an active social life. Other studies, too, have shown that people who have few or no social ties, or who are generally less connected with other people are at greater risk of developing memory loss.
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The Health and Retirement Study
Researchers from the Harvard School of Public Health used data from the Health and Retirement Study (HRS), a survey based on a representative sample of 16,000 U.S. residents over the age of 50. The large number of subjects meant that the Harvard researchers could compare the effects of social connections among different groups of people, such as men and women, and people from different ethnic or socioeconomic backgrounds.
Also, the HRS collected data from 1998 to 2004. This was a long enough period of time for the researchers to see if there was a cause and effect relationship between social connections and dementia. They wanted to know: Does social integration protect against memory loss? Or is the reverse true: Do people who suffer cognitive decline tend to socialize less than average?
The results were impressive. People who interacted the most with family, friends and other people were less likely to show a decline in memory. This protective effect was particularly strong among the people who were most at risk for dementia — those who had fewer than 12 years of education and among people with blood circulation problems (defined as high blood pressure, diabetes or stroke).
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The Kaiser Permanente Study
The second article, based on a study done at Kaiser Permanente Southern California, a large health maintenance organization, looked at the effect of social networks on more than 2,200 female members. These participants, who were at least 78 years old, did not show any symptoms of dementia in 2001. The women were given follow-up interviews over the next four years.
The authors found that women with large social networks were less likely to develop dementia than were more isolated women. This was true even when the researchers controlled for a woman's age, education, depression and other health conditions.
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How Social Ties May Protect Against Memory Loss
While these two studies didn't tell us how strong family ties and friendships protect against intellectual decline or memory loss, the authors had some ideas.
- Regular social contact may not only promote healthier behaviors but also may make it easier to get medical help when you need it. Friends and family may give helpful nudges to get a troubling symptom evaluated by a doctor. They also are more likely to give practical assistance, such as helping to make the doctor appointment or even providing a ride to the medical office.
- Peer pressure may be a good thing as we get older. That is, people often feel motivated to do what other people in their lives are doing to take care of themselves.
- Social activity may correlate with physical activity. Getting together with other people for any reason pushes a person to do more walking and exert more energy. In other words, group pursuits may simply lead to more activity and exercise.
- People who are more integrated into a social network and feel supported in their relationships may experience less stress. Stress hormones that may cause the brain to function less well don't get triggered. Lower stress may also reduce the risk of vascular disease. Better vascular health helps keep the brain's blood supply intact, which also improves brain function.
- A rich social life may be more emotionally and intellectually stimulating. This exercises the brain and fosters better neuronal connections and even nerve-cell growth.
The authors acknowledged that the studies had their limitations. There was not much information about the quality of the social connections of the people in the studies. And one of the studies only included women. Nevertheless, the studies were unique because they drew on a large pool of data collected over several years. The results supported the theory that social networks are a boon to intellectual health in later life.
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The Most Powerful Medicine We Have
This is all good news, because the factors supporting cognitive health are relatively widely available. The drug treatments for dementia have been disappointing at best. So it is great to learn that we can improve our chances of avoiding intellectual decline by staying in touch with the people in our lives or by making new social connections.
Clinicians and policy makers can also take note of this: There is no doubt that quality of life improves when older adults stay engaged and socially involved rather than when they isolate. Now we find out that social ties may be good brain medicine, too. Until medications for dementia improve, an active social life may still be the most powerful medicine we have.
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Michael Craig Miller, M.D. is editor-in-chief of the Harvard Mental Health Letter and an assistant professor of psychiatry at Harvard Medical School. Dr. Miller has an active clinical practice and has been on staff at Beth Israel Deaconess Medical Center for more than 25 years.