The internet and cell phones are supposed to bring people closer together; but in terms of living in close proximity to friends and family, we're moving further apart. And this lack of good social networks may be taking a toll on our health, according to a new study.

The number of Americans who say they have no one to confide in has tripled in the last 20 years.

The researchers, from Brigham Young University, point out that in both quality and quantity, social relationships are decreasing in industrialized societies. People no longer live close to their families; they're also marrying later in life and living alone more. The number of Americans who say they have no one to confide in has tripled in the last 20 years.

These disturbing statistics prompted the researchers, led by Julianne Holt-Lunstad, to examine what kind of connection there may be between the quality of people's relationships and their lifespan. The team reviewed 148 previous studies that included over 300,000 participants. The authors made sure that all the studies included looked at how much social support the participants received (there were some strict guidelines, like the social support had to be human, not solely from a spouse, and it had to be received rather than only given, among other qualities).

The authors' results "indicated a 50% increased likelihood of survival as a function of stronger social relations." In other words, people with the best social networks were 50% less likely to have untimely deaths than people who were less connected with others.

More concretely, having a strong social support system rivals quitting smoking in terms of the boost in lifespan it can give people (this is not to say you should take up smoking if you have a good support system, because it would surely negate the effects of your social network!). Relationships have more impact on your health than many other risk factors, such as obesity or physical inactivity.

The authors also point out an interesting connection between their study and a discovery made over fifty years ago, when officials began noticing that babies in orphanages had much higher death rates than other children. They say that the "[l]ack of human contact predicted mortality. The medical profession was stunned to learn that infants would die without social interaction." After this realization, they say, policies changed, which helped bring down the death rate in orphanages.

Doctors and media campaigns should add social networks to the list of risk factors they are most concerned about (like smoking and obesity), the researchers say. It will be interesting to see in coming years how healthcare, public policy, and media campaigns change to reflect the findings of the current study. As the authors say: "Individuals do not exist in isolation".

The study was published in the July 27th issue of PLoS Medicine.