The results of a newly published study of 12 million Facebook users suggests that using the social network is associated with living longer, but there’s a catch: the benefit appears to come when using Facebook serves to maintain and enhance someone’s real-world social ties.

“Interacting online seems to be healthy when the online activity is moderate and complements interactions offline,” said William Hobbs, Ph.D., the first author of the study, which is published in the Proceedings of the National Academy of Sciences. He worked on the study as a doctoral student in political science at the University of California, San Diego, and is now a postdoctoral fellow at Northeastern University. “It is only on the extreme end, spending a lot of time online with little evidence of being connected to people otherwise, that we see a negative association,” he added.

To arrive at their conclusions, the researchers matched California Facebook users with vital records from the California Department of Public Health. To preserve privacy, after being automatically matched by name and birthdate, the data were de-identified and aggregated.

The researchers studied counts of online activity over six months, comparing the activity of those still living with those who had died. All of those studied were born between 1945 and 1989 (meaning that today, all of them are aged from their late 20s to their early 70s), and all the comparisons were made between people of similar age and gender.

What they found:

  • In a given year, the average Facebook user is about 12% less likely to die than someone who doesn’t use the site. That finding may be due to social or economic differences between users and nonusers, however.
  • People with average or large social networks, in the top 30% to 50% of users, lived longer than those in the lowest 10%, a finding consistent with classic studies of offline relationships and longevity.
  • Those on Facebook with highest levels of offline social integration — as measured by posting more photos, which suggests face-to-face social activity — have the greatest longevity. Online-only social interactions, such as writing wall posts and messages, revealed a nonlinear relationship. That is, moderate levels were associated with the lowest mortality.
  • Facebook users who accepted the most friend requests lived the longest.

“Social relationships seem to be as predictive of lifespan as smoking, and more predictive than obesity and physical inactivity,” said James Fowler, Ph.D. (pictured), the senior author and a professor of political science and global public health at UC San Diego. “We’re adding to that conversation by showing that online relationships are associated with longevity, too.”

The investigators hope that subsequent research leads to a better understanding of what kinds of online social experiences are protective of health.

“What happens on Facebook and other social networks is very likely important,” Fowler said. “But what we can’t do at this time is give either individual or larger policy recommendations based on this first work.”