Key to Good Health? You've Got to Have Friends, Study Finds

The University of North Carolina researchers are the first to connect the size of social networks to health measures such as high blood pressure, inflammation, and waist circumference.

Having a large network of friends, from the beginning of life and throughout, is a key to staying healthy, according to a new study from researchers at the University of North Carolina at Chapel Hill.

While scientists have long believed that friendships are good for you, this study is the first quantify it: researchers were able to connect the number of social ties with concrete measures of belly fat, inflammation, and high blood pressure, all of which are linked to heart disease, stroke, and cancer when elevated.

The study was published in the Proceedings of the National Academy of Sciences.

“Based on these findings, it should be as important to encourage adolescents and young adults to build broad social relationships and social skills for interacting with others as it is to eat healthy and be physically active,” said Kathleen Mullan Harris, PhD, who is the James Haar Distinguished Professor at UNC Chapel Hill.

The findings support earlier work with senior citizens, who are known to live longer if they keep up social ties. This time, however, the science shows actual biological benefits to maintaining healthy relationships with friends, as well as proof that doing so reduces health risks at every stage of life, not just in the later years.

The researchers found that the size of a person’s social network affected one’s health in both early and late adulthood. In the teen years, isolation could raise the risk of inflammation just as much as being physically inactive. Being socially active protected teens against obesity. In old age, those who were too isolated fared worse than persons with diabetes in terms of risk of developing hypertension.

Quality of connections mattered more than quantity in middle adulthood, according to the researchers. Having social ties that provided support rather than strain mattered more at this stage of life.

To conduct the study, researchers used data from 4 surveys of the US population that covered the lifespan from adolescence to old age and evaluated 3 aspects of relationships: social integration, social support, and social strain. They studied how an individual’s relationships were associated with 4 markers associated with mortality risk: blood pressure, waist circumference, body mass index, and circulating levels of C-reactive protein, which measures inflammation. One of the surveys was the National Longitudinal Study of Adolescent to Adult Health.

“Our analysis makes it clear that doctors, clinicians, and other health workers should redouble their efforts to help the public understand how important strong social bonds are throughout the course of our lives,” said Yang Claire Yang, PhD, a professor at UNC Chapel Hill and a member of the Lineberger Comprehensive Cancer Center.


Yang YC, Boen C, Gerken K, Li T, Schorpp K, Harris KM. Social relationships and physiological deeterminants of longevity across the human life span. Proc Nat Acad Sci. 2016; 201511085 doi:10.1073/pnas.1511085112.