In low-income, minority communities, tight-knit social connections -- with family members, friends, and neighbors -- can lead people to eat healthy and be physically active, but in some cases it may actually be an obstacle to a healthy lifestyle, according to new research by investigators at Dana-Farber Cancer Institute and the Harvard School of Public Health.

To account for this paradox, researchers theorize that for people made vulnerable by low income and poor access to services, the demands of social responsibilities -- being a single parent or caregiver to an ill or elderly relative, for example -- can deprive them of the time and energy to adopt good health habits, although further research is needed to verify that hypothesis, investigators say.

The study, to be presented on Apr. 13 at the annual meeting of the Society of Behavioral Medicine in New Orleans, is one of a limited number to examine the impact of social ties and support on healthy behavior in low-income, racial and ethnic minority areas. The abstract is published in the Annals of Behavioral Medicine.

"It's well documented that social relationships can have a positive or negative impact on people's health habits, but little attention has been paid to this issue in low-income groups," says the study's lead author, Sara L. Tamers, PhD, MPH, of Dana-Farber and the Harvard School of Public Health (HSPH). "Our findings raise the possibility that for this population, some of the constraints on a healthy lifestyle are social ones. If further research bears that out, programs to encourage healthier living will need to take these factors into account."

Data for the study was culled from the Health in Common (HIC) Study, which was conducted between 2005 and 2009 to examine cancer risks for racially and ethnically diverse, low-income people in the Greater Boston area. As part of the HIC, participants were asked the number of close friends, family members, and neighbors who provided support, and these data were tracked with participants' dietary and exercise habits.

The findings present a mixed picture of the benefits and potential downsides of social ties as they relate to a healthy lifestyle. People with many close friends, for example, tended to eat more servings of fruit and vegetables per day than those with fewer friends. On the other hand, people with strong relationships with many family members tended to consume more sugary drinks and fast food than others did.

"Social relationships are critical for anyone's well-being," Tamers remarks. "But for people in difficult economic circumstances, those same relationships may be a burden that limits their ability to eat right and get enough exercise. More research is needed to determine if this is indeed the case -- and, if so, how we can tailor community health programs to these circumstances."