Short of shirking all your cares, living in a fog of disinfectant, or moving to a cave to avoid virus-infected fellow humans, what's a good way to prevent the sniffles? Social support. Having lots of friends, neighbors, even having a boss, it turns out, correlates with resisting colds.
In one way, this should not be a surprise, since social networks are known to be extremely healthy. "We know that people with good and diverse social relations live longer," Cohen says. To find out if they also help avoid colds, the Pittsburgh researchers counted the number of "social roles" each subject played. The 12 possible roles included being a parent, a child, a church member and a worker.
The results were the kind of straight-line graph that are beloved of epidemiologists: 62 percent of those with three or fewer roles got a cold, compared to 43 percent of those with four or five roles, and only 35 percent of people with six or more social roles.
But didn't people who smoked cigarettes or flatly refused to wear their mittens also get more colds? Yes, such "health practices" did play a role: smokers got 2.45 times as many colds as non-smokers. The Why Files dreamed up that one about mittens.
But when those factors were removed statistically, the positive effects of social support, and the negative effects of stress, remained.
But just as mom always urges you to remember your mittens, The Why Files urges you not to confuse correlation (defined) with causation. Remember: If correlations proved causation, the rooster's crow would cause the dawn. Ain't likely.
What we're getting at is this: Cohen may have figured out what's going on. But has he figured out
why it's going on?
Say stress and social support affect your susceptibility to colds. It stands to reason that they must be changing something measurable in the body -- perhaps something in the immune system, or the hormonal system, or the brain. But the problem is, Cohen says, that while "stress and social conflict are associated with greater susceptibility to colds, we haven't learned anything about the psychological or biological pathways that mediate [cause] this effect."
Cohen saw hints that some hormones were affected by stress, but it was not enough to explain the effect. And oddly enough, high levels of natural killer cells correlated with more colds, not fewer.
Still, the explanation probably does lie with the immune and/or the hormonal systems, Cohen says, even though our ability to measure and understand them are both limited. It's known that lymphocytes (defined) have receptors (defined) for various hormones, meaning that hormones can "speak" directly to these immune-system warriors.
And the immune system is so complex that it's easy to measure the wrong thing at the wrong time, or in the wrong place. Cohen notes that while his study relied on measurements in mucus and blood, "That's not where the action is. It's in the internal organs" like the spleen and thymus. "If I knew what was happening here, I could save a few years of research," he concludes. "There are a myriad possibilities."
Medically speaking, death is the "ultimate outcome measure."
Can social support extend the life span of breast cancer patients?
