Researchers who study the healthiest and longest living people say that there is a common lifestyle characteristic that contribute to their longevity: strong family and social engagement.

A new study found that family and friends do make us live longer with 50 percent more likelihood than those without strong personal relationships.

Strong relationships and longevity may not be directly connected, but relationships have more than just emotional benefits that can influence longevity and health, according to study author Julianne Holt-Lunstad, an associate professor of psychology at Brigham Young University.

Social contact seem to be an important anchor that help overcome negative or stressful events in life, reduce risk-taking behavior and provide meaning in life.

The research published in the July issue of PLoS Medicine combined the results of 148 studies found that lack of friends is as damaging as smoking 15 cigarettes a day or being an alcoholic. However, having strong relationships, such as those with friends, family, roommates and spouses, have a greater effect than exercising or losing weight.

Holt-Lunstad and her team followed 308,849 people from North America, Europe, Asia and Australia for seven and a half years. Regardless of age and health status, strong relationships had an effect comparable to that of quitting smoking, weight loss or decreased alcohol use.

Study authors noted that the quantity and quality of relationships is decreasing in this era of technology.

"Obesity is a public health problem that needs to be addressed through effective social programs and policies, [and] the same is true of alcoholism and high blood pressure," Holt-Lunstad says. "Our data make the case that strength of social relationships needs to be added to the list of public health concerns."