Lots of Friends = Longevity

A healthy social life may be as good for your long-term health as avoiding cigarettes, according to a massive research review released Tuesday by the journal PLoS Medicine.

Researchers at Brigham Young University and the University of North Carolina at Chapel Hill pooled data from 148 studies on health outcomes and social relationships — every research paper on the topic they could find, involving more than 300,000 men and women across the developed world — and found that those with poor social connections had on average 50% higher odds of death in the study's follow-up period (an average of 7.5 years) than people with more robust social ties.

That boost in longevity is about as large as the mortality difference observed between smokers and nonsmokers, the study's authors say. And it's larger than differences in the risk of death associated with many other well-known lifestyle factors, including lack of exercise and obesity. "This is not just a few studies here and there," says Julianne Holt-Lunstad, lead author on the review and an associate professor of psychology at Brigham Young University. "I'm hoping there will be recognition from the medical community, the public-health community and even the general public about the importance of this."

The friend effect did not appear to vary by sex or by age, with men and women of all ages and health statuses showing roughly equal benefit. Nor were lonely people unusually susceptible to any one disease in particular.

But if it's true that we get by with a little help from our friends, then how, exactly, do our friends do it? That is, how does "social integration" — measured by surveys and questionnaires about friends, family size, marital status and the number of household residents — influence long life? The short answer is that we don't really know yet. "The truth of the matter is that the critical evidence on psychosocial processes and health have come about only within the last 10 to 15 years — even though there's been a lot of theory on it since the 1970s," says psychology professor Bert Uchino at the University of Utah.