A new study says that friends and neighbors play a key role in determining the physical and mental health of an individual.
The study involving identical twins found that the siblings with tight-knit social circles were healthier than their counterparts who didn't feel as connected to their communities, despite their very similar DNA and upbringing.
"Social trust, sense of belonging and community participation were each significantly associated with health outcomes," the researchers found.
Physical health, as reported by the study participants, remained significantly associated with social trust" even among twins.
However, social capital, the factors that add up to a feeling of connection to the community, did not affect rates of major depression, found the study.
The study looked at survey data from the National Survey of Midlife Development in the U.S., focusing on 944 sets of twins, all between ages 25 and 74. More than 1,000 of the 1,888 participants said they were either in very good or excellent health.
"We directly compared twins, and found the effect of social trust regardless of genetics and upbringing," said study coauthor Takeo Fujiwara.
An overwhelming majority of participants, 95 percent, perceived an absolute connection between their physical health and social trust, said Fujiwara.
Fujiwara and co-author Ichiro Kawachi, a professor of social epidemiology at the Harvard School of Public Health, say social capital includes factors such as community participation, volunteer work and comfort within a neighborhood..
"This is very encouraging. What society or community can do may change the health of residents, regardless of predisposing factors," Fujiwara said.
The study appears in the August issue of the American Journal of Preventive Medicine.