Social isolation, loneliness could be greater threat to public health than obesity, researchers say.

Loneliness and social isolation may represent a greater public health hazard than obesity, and their impact has been growing and will continue to grow, according to research presented at the 125th Annual Convention of the American Psychological Association.

“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,” said Julianne Holt-Lunstad, PhD, professor of psychology at Brigham Young University. “Yet an increasing portion of the U.S. population now experiences isolation regularly.”

Approximately 42.6 million adults over age 45 in the United States are estimated to be suffering from chronic loneliness, according to AARP’s Loneliness Study. In addition, the most recent U.S. census data shows more than a quarter of the population lives alone, more than half of the population is unmarried and, since the previous census, marriage rates and the number of children per household have declined.

“These trends suggest that Americans are becoming less socially connected and experiencing more loneliness,” said Holt-Lunstad.

To illustrate the influence of social isolation and loneliness on the risk for premature mortality, Holt-Lunstad presented data from two meta-analyses. The first involved 148 studies, representing more than 300,000 participants, and found that greater social connection is associated with a 50 percent reduced risk of early death. The second study, involving 70 studies representing more than 3.4 million individuals primarily from North America but also from Europe, Asia and Australia, examined the role that social isolation, loneliness or living alone might have on mortality. Researchers found that all three had a significant and equal effect on the risk of premature death, one that was equal to or exceeded the effect of other well-accepted risk factors such as obesity.

“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. “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.”

Holt-Lunstad recommended a greater priority be placed on research and resources to tackle this public health threat from the societal to the individual level. For instance, greater emphasis could be placed on social skills training for children in schools and doctors should be encouraged to include social connectedness in medical screening, she said. Additionally, people should be preparing for retirement socially as well as financially, as many social ties are related to the workplace, she noted, adding that community planners should make sure to include shared social spaces that encourage gathering and interaction, such as recreation centers and community gardens.