A UCLA study took the long-recognized connection between loneliness and poor health to a new level by uncovering the genetic consequences of loneliness (see the full text of the study here). Its results are compelling, both on their own and as an opening salvo in medicine’s new campaign to understand how perception, feelings, and interaction with others determines health.

Measuring loneliness (referred to in the study as “social isolation”) through the UCLA loneliness scale, researchers found that “feelings of social isolation are linked to alterations in the activity of genes that drive inflammation, the first response of the immune system.” At the same time, “key gene sets were under-expressed”—in other words, were not as functional as you’d expect them to be–in lonely individuals, “including those involved in antiviral responses and antibody production.”

In other words, loneliness fundamentally alters our immune system. As one author put it, “…the biological impact of social isolation reaches down into some of our most basic internal processes …the activity of our genes; changes in immune cell gene expression in [ways that are] specifically linked to the subjective experience of social distance.” This is important: it’s feeling alone that matters.

This is by no means the first time research has shown that social isolation is detrimental to health. A 2001 study in Psychosomatic Medicine showed that patients suffering from coronary artery disease with three or fewer people in their social support network had a significantly increased risk for cardiac mortality. In 2004 a study published in Neurology showed that “pre-stroke social isolation is a predictor of outcomes,” with lonelier people having poorer outcomes. Two years later a University of Chicago study showed that men and women between 50 and 68 years old who scored higher on measures of loneliness also had higher blood pressure—a major risk factor for heart disease— than did non-lonely people.

But the UCLA study is the first to show that the subjective experience of isolation affects us at the genetic level. This is big news. As Maggie has noted in the past, there are five main determinants of health: genetics, social circumstances, environmental exposures, behavioral patterns, and health care. The UCLA findings bridge social circumstances, behavioral patterns, and genetics: social context and engagement with others, in fact, alters one’s genes.

At the level of the individual, this is fascinating, but here’s the million-dollar question: does this dynamic carry over to the group level? To paraphrase the UCLA study, is there “a functional genomic explanation for elevated risk of inflammatory disease” in groups “who experience vast levels of subjective social isolation”? Are there health consequences to the subjective experience of inequality?

There is a long-proven correlation between socioeconomic status and health. Typically these disparities are thought to be due to poor access to care, whether that’s due to geographic segregation, medical discrimination, or high costs. Education is also often cited as a factor.

But when it comes to poor health, the UCLA study gets you thinking: is being part of a socially isolated group just as subjectively harmful—and thus genetically significant—as being a socially isolated individual? Maybe it’s not just that the poor lack access to health care; maybe they also recognize their own marginalization and so, on the whole, are more prone to the genetic consequences of isolation.

And we do know that some feelings relevant to social isolation do follow a clear socioeconomic pattern. If you take a look at the gradient of social trust in America, (the extent to which individuals have faith in others), you can see that the more education you have and the more you earn, the more you have faith in others. White people also have more social trust than blacks or Latinos.

Obviously, social trust isn’t exactly the flip side of social isolation. But it’s reasonable to think that there’s some correlation between the two—you’re more likely to mistrust people if you don’t feel close to them. If the “have-nots” are in poorer health and also are mistrustful of others, to what degree are these two phenomena related?

The UCLA study shows how much we have to learn about the social dimensions of health—bridging the divide between the social, the psychological, and the physiological is something that we don’t do often enough.

If any of our readers knows of some research that touches on some of what I’ve discussed, please let us know. I’ll be sure to mention it on the blog.