This latest study says loneliness is on a par with obesity in terms of public health risk. Spyros Papaspyropoulos/Flickr (CC BY-NC-ND 2.0)

Although we’re more connected than ever in some ways, many parts of the world are facing what’s being called a “loneliness epidemic”, with over 42 million adults over age 45 in the US suffering from chronic loneliness.

New research says that this widespread social isolation is a major threat to public health, perhaps even deadlier than obesity. The issue is only set to get worse too because of a decreasing number of children per household, declines in marriage, and an aging population.

“Being connected to others socially is widely considered a fundamental human need — crucial to both well-being and survival. Extreme examples show infants in custodial care who lack human contact fail to thrive and often die, and indeed, social isolation or solitary confinement has been used as a form of punishment,” Julianne Holt-Lunstad, professor of psychology at Brigham Young University, said in a statement.

“Yet an increasing portion of the U.S. population now experiences isolation regularly.”

The study, the largest ever of its kind, was recently presented at the 125th Annual Convention of the American Psychological Association. The researchers used data from two previous meta-analyses. One involved 148 studies, representing more than 300,000 participants across the US, and the second involved 70 studies representing more than 3.4 million individuals primarily from North America but also from Europe, Asia, and Australia.

Using both of these studies, they concluded that social isolation, loneliness, or simply living alone had a significant and equal effect on the risk of premature death. They also found that greater social connection is associated with a 50 percent reduced risk of early death.

Everybody has felt lonely at some point in their life. However, chronic loneliness is a very different beast. Numerous other studies have shown a link between loneliness and physical health difficulties, from fragmented sleep and dementia to lower cardiovascular output and a weakened immune system. The mechanism is not exactly crystal clear, however, it is likely to be a combination of psychological factors taking their toll on physical health and the absence of a support network.

“There is robust evidence that social isolation and loneliness significantly increase risk for premature mortality, and the magnitude of the risk exceeds that of many leading health indicators,” said Holt-Lunstad.

The researchers hope their meta-study will help highlight the importance of this silent issue, allowing us to address it from a societal public health level, such as including social connectedness in medical screenings, to an individual level, like preparing for retirement socially as well as financially.

“With an increasing aging population, the effect on public health is only anticipated to increase. Indeed, many nations around the world now suggest we are facing a ‘loneliness epidemic.’ The challenge we face now is what can be done about it.”