What's the key to a long life? After years of working with older people, gerontologist Thomas Glass knew the answer wasn't simply good health. "There are people who seem relatively healthy who die in their 60s," says Glass, an assistant professor at the Harvard School of Public Health.
"There are others with all kinds of chronic diseases who make it into their 80s and 90s," adds Glass. "The question is why?" In findings published in the August 1999 in the British Medical Journal, he and his colleagues came up with a surprising answer.
In a study of 2,761 people 65 and older who were followed for a period of 13 years, the researchers tracked participation in 14 activities, which included everything from swimming and brisk walking to shopping, doing volunteer work, and playing cards with the gang. They found that people who spent time in social activities -- volunteering, running errands, or getting together with friends -- fared just as well as those who spent the time exercising.
"Social engagement was as strong as anything we found in determining longevity," says Glass. "It was stronger than things like blood pressure, cholesterol, or other measures of health."
People Who Need People
Dozens of findings over the past two decades have shown how important social connections can be. In another study, University of Michigan epidemiologist James House and his team interviewed and examined 2,754 adults over a period of nine to 12 years.
Their results, published in the American Journal of Epidemiology in 1982, showed that men who reported more social relationships -- going to movies, church meetings, classes, or trips with friends or relatives, for example -- were significantly less likely to die during the study period. Socially active women also benefited, although not quite as dramatically.
Marriage, too, turns out to have important health benefits. In the December 1999 issue of Neurology, researchers at Bordeaux University in France reported that among 2,800 volunteers followed over a five-year period, married people were one-third less likely than the never-married to develop Alzheimer's disease.
Social Interaction and Immunity
There are plenty of reasons why friends and loved ones may keep you healthy, experts say. A spouse can look after you when you get sick, for instance, which may mean a speedier recovery from serious illnesses. People with the support of friends or spouses typically feel a greater sense of self-esteem and so take better care of themselves by adopting a healthy lifestyle. A strong social network may also help reduce stress, and there's good evidence that psychological well-being can promote physical health.
One way is by boosting the immune system, which wards off disease. "We've seen again and again that people who are lonely or socially isolated show signs of suppressed immunity," says Ohio State University immunologist Ronald Glaser, who along with his wife Janice Kiecolt-Glaser pioneered the study of how mental states affect the immune system.
In a 1984 study published in the January-February issue of Psychosomatic Medicine, they found that patients who scored above the median level on loneliness tests had significantly fewer active natural killer cells -- cells that attack germs.
Reach Out and Touch Someone
Gerontologist Glass thinks the latest findings should alert us to the importance of being sociable. "As a society, we should be finding more ways for people, especially older people, to stay involved and active. At any age, we need to begin to think beyond the boundaries of the Stairmaster.
"Physical fitness is important, but social engagement is turning out to be just as critical to longevity. What I tell people is, 'Find something you really like doing that involves other people, whether it's playing cards or walking in the mall.' Social engagement adds a sense of purpose to people's lives. It also seems to add years to those lives."