Probing the ever elusive mind-body connection, a new study of 276 people who got purified cold viruses sprayed up their noses has reached a conclusion that is nothing to sneeze at: Loners were four times more likely to come down with a cold than people rich in relationships.
The study strengthens the popular but difficult-to-prove notion that an active network of family, friends, neighbors and even co-workers can bolster one’s resistance to disease, perhaps by activating the immune system.
“This is the first time that anyone has directly linked personal relationships with an immunologically relevant disease outcome,” said Janice Kiecolt-Glaser, a clinical psychologist at the Ohio State University Medical Center and co-editor of a leading textbook on stress and immunity.
The new evidence, which appears today in the Journal of the American Medical Association, may even figure in future political debates, researchers speculate. To some, it supports the possibility that the much-lamented tearing of America’s social fabric - from the loss of community spirit to the willy-nilly scattering of families across the continent directly affects people’s physical health.
If backed up by other studies, Kiecolt-Glaser said, “this may have a major implications for public policy and patient management.”
The researchers who conducted the study, led by psychologist Sheldon Cohen of Carnegie Mellon University in Pittsburgh, cannot explain precisely why socially deprived people were comparatively worse at warding off a cold virus. But they say they ruled out secondary factors, such as the tendency of isolated people not to exercise and of older people, who are more vulnerable to colds, to be isolated.
Indeed, when the researchers adjusted all the odds, they found that having a minimum of social relationships increased one’s likelihood of succumbing to the viruses more so than smoking - a factor known to hasten a cold infection. Cohen speculated that the germ-fighting benefits of a diverse social network outweigh the risk of contracting a cold from having many social contacts.
Cohen stopped short of recommending that everyone join a club or drop in on long-lost relatives as a way to avoid getting the sniffles. But he also suggested that fostering strong and diverse personal ties were part of a prudent approach to well-being. “It certainly couldn’t hurt and it might even help,” he said.
The volunteers, 18 to 55 years old, got $800 for risking their sinuses for science. After undergoing numerous medical tests - to make sure they didn’t already have a cold, for instance - they checked into a hospital and were quarantined for five days after being exposed to the cold viruses. Every tissue they blew into was saved for analysis.
The researchers also probed the subjects’ personality and social relationships, tracking the number of people with whom they had regular face-to-face or phone contact, how often they made contact and the variety of those contacts. Those ranged from workmates to spouses to fellow churchgoers.
Roughly, they found that 35 percent of people with six or more cohesive social relationships came down with a cold, compared with 62 percent of those with three or fewer such relationships. Adjusting that crude data to account for other risk factors for colds like smoking, age, exercise level and vitamin C intake, the researchers found a fourfold difference in cold susceptibility between those with the highest and lowest “social diversity network.”
The importance of the study is that it followed people under controlled conditions from the time of deliberate exposure to a disease agent until they got better.
Other studies attempting to link social support and disease outcomes have necessarily been observational. For instance, a widely cited study of women with metastatic breast cancer found that those who belonged to a support group for women with the disease lived longer than those who did not. But critics have pointed out that women in the support group may have been healthier to begin with, throwing the group benefit itself into doubt.
Similarly, other researchers, including Kiecolt-Glaser, have studied the immune system of people with differing social support who were given a vaccine. And while that study suggested that people’s personal ties do affect their immune system, it did not correlate that to actual disease resistance.
The study by Cohen and colleagues, including Dr. Jack Gwaltney of the University of Virginia, a noted expert on cold viruses, helps fill in the gap.
Virologist Ronald Glaser, Kiecolt-Glaser’s husband and collaborator, said the Cohen study adds a big piece to the puzzle of the evolution of human beings as social animals. “It makes me wonder that if our evolution as a social species is so strong that without social support we have dramatic and real health consequences.”