The front page story yesterday about how loneliness is “lethal” would lead you to think that we just discovered it. The fact is that scientists have known for some time that loneliness and social isolation put people at higher risk for heart attacks, cancer, Alzheimer’s disease and other conditions. What’s new in the past couple of months is that studies of the genome are yielding information on the specific mechanisms that make it happen.

Because social cohesiveness and cooperation were vitally important in early human history, the brain is rigged to see a lack of strong ties as a signal of danger. Just like any other kind of stressor, that signal puts the body on the alert, even down to the cellular level. In studies of both humans and macaque monkeys, researchers have discovered that social isolation leads to specific genetic changes that turn up inflammatory processes in the body and turn down the production of antibodies against viruses and other pathogens. These genomic adaptations are linked to human evolution, designed for our survival, and are closely related to the body’s stress response.

This heightened fight-or-flight response, activated on a chronic basis, results in increased inflammation and a reduced immune response, leading to significant long-term damage. The mechanism is observed in both directions: a change in gene expression predicts future loneliness, and loneliness predicts future gene expression. In older adults, perceived loneliness leads to an increase of 14% in premature deaths.

It’s worth mentioning that loneliness is not the same as being alone. What matters is whether someone feels connected, and feels satisfied with the connections he or she has. Plenty of people (myself included) relish some solitude on a pretty frequent basis, but that doesn’t equate to loneliness or isolation.

While we often focus on the elderly being socially isolated, loneliness can strike anyone, from the bullied schoolchild to the working adult with social anxiety. In the book “Fear”, Thich Nhat Hanh wrote about original fear and original desire. He says original fear started at birth when we were pushed, helpless, out into the world, unsure whether anyone would take care of us. That fear “was born along with the desire to survive. This is original desire.” Original fear and original desire stay with us as we grow, especially the fear that no one will love and care for us. To me, loneliness is one manifestation of that fear.

You may be reading this and thinking, “I’m not lonely – I don’t need to worry about this.” There’s a bigger picture, however, that might concern you. Analysis of social networks by Nicholas Christakis and James Fowler has shown that loneliness (like obesity, quitting smoking and other habits and trends) is contagious. So the more time that people in your social network, even those on the fringes of it, spend feeling isolated, the more likely it is to spread to others in the network. Over time, there’s a possibility that more of us start experiencing those feelings.

In a world where connection is constant, but often feels unsatisfying, how can we feel less lonely? How can we help others who are lonely? Forced togetherness is not the answer. Interestingly, some research has shown that a mindfulness based stress reduction program is more successful than social networking or community programs are at reducing feelings of loneliness in the elderly. MBSR has also been shown to turn down the pro-inflammatory processes in the body. The focus on present moment may be guiding attention away from the fear of being alone.

Christakis has said that when you help “the people on the margins of the network, you help not only them but help stabilize the whole network.” It would be wise to consider how we can do more to reach those people and offer them positive social connections. Maybe we can light up the network with love rather than fear.