New research suggests that neighborhood and community-level factors -- not just individual factors like diet, exercise and education -- may influence people's diabetes risk.

As the linked epidemics of obesity and diabetes continue to escalate, a staggering one in five American adults is projected to have diabetes by 2050.

Public health researcher at Drexel University in Philadelphia found that 12 percent of the risk of diabetes correlated with neighborhood physical and social environment factors when adjusted for respondents' age and sex -- meaning they would expect diabetes rates to drop by 12 percent if the neighborhood environment were improved.

Another nearly 12 percent of risk correlated with education when adjusted for respondents' age and sex. Excess weight (overweight or obese) and race/ethnicity still remained larger contributors to the odds of diabetes.

"Too often, we focus exclusively on the individual in solving the problem," Ana Nunez, coauthor of the study, said in a statement. "Here we found that we also need to focus on the healthiness of the community if we want to improve overall health and ultimately decrease health care costs."

For the study, researchers collected and analyzed data from residents living in Philadelphia, which has the highest diabetes rate among the nation's largest cities.

To evaluate the health impact of disadvantaged urban communities, researchers developed an indicator of people's physical and social environment (PSE) based on their answers to certain questions on a large region-wide health survey. These questions asked about the availability of healthy food, use of local recreational facilities, helpfulness of neighbors and other factors, in addition to poverty level. The survey also asked more than 17,000 participants who lived in 46 Philadelphia zip codes about personal factors that affected their risk of diabetes. These questions included whether they were overweight or obese, their physical activity, fruit and vegetable intake, age, sex, race/ethnicity and smoking status.

Researchers found that scores for the physical and social environment varied widely across neighborhoods. The neighborhoods with worse PSE statuses had a higher prevalence of diabetes. In areas where residents had higher rates of overweight and obesity or lower education attendance, there were also higher rates of diabetes. Between the survey periods in 2002 and 2010, the number of neighborhoods with higher rates of diabetes increased substantially.

"We want to stop the epidemic of diabetes and eliminate health disparities in communities," Longjian Liu, lead author of the study, said in a statement.

Researchers conclude that working towards improving the health quality of an entire neighborhood or city shows promise in helping to reduce the risk of disease.

The findings are detailed in the journal Advances in Preventive.