Poor women, who moved to lower-poverty neighbourhoods, showed better Type 2 diabetes control and other health benefits, say U.S. researchers who called for changes in government initiatives to fight obesity.

In an experiment described in Wednesday's online issue of the New England Journal of Medicine, researchers followed 4,498 poor women and children who were enrolled in a program called Moving to Opportunity in 1994 to 1998. Food Drive coordinator Allan Carter, left, and Orange County Food Bank driver Cliff Nelson unload a mail truck full of donated food during May's food drive in California. Changing the neighborhood environment of poor women may help their health, researchers have found. Ken Steinhardt/Orange County Register/Associated Press

Among the group of women who were offered housing vouchers to move to lower-poverty neighborhoods, the rates of morbid obesity and diabetes were both about one-fifth lower than in the control group, lead author Yens Ludwig, a professor at the University of Chicago, and his co-authors found.

"What you see 10 to 15 years down the road is giving moms a chance to move from high to low poverty areas has about the same impact on diabetes as what you see from medical interventions that were explicitly designed to reduce diabetes," said Lunwig.

During the study, participants in public housing projects in Baltimore, Boston, Chicago, Los Angeles and New York volunteered for a random lottery that offered the chance to use a housing voucher subsidy to move into a lower-poverty area.

Others families randomly assigned to a control group received no special assistance.

All of the volunteers gave blood samples to test for diabetes and had their heights and weights measured.

Lunwig said the findings highlight the importance of finding out what specific aspects of the social or physical environment reduce the risk of diabetes and obesity, such as:

• Greater access to grocery stores.
• More opportunities for physical activity.
• Feelings of greater safety and reduced psychological stress.

The results could also help explain the gaps in obesity and diabetes prevalence across race and ethnic lines in the U.S., the researchers said.

Previous studies not involving health suggested that changes in the neighborhood environment, rather than the act of moving itself, were responsible for the effects, the study's authors noted.

Benefits of improving environment

The findings suggest it may take investments in low-income neighbourhoods along with health care interventions to reverse the growing obesity and diabetes epidemics, said Robert Whittacker, a professor of public health and pediatrics at Temple University in Philadelphia.

"For people to be healthy they need more than health care," Whittacker said, commenting on the study. "This study is one of the strongest pieces of evidence yet that improving the environments where low income families live can have meaningful impact on their risk of developing important chronic diseases."

The large social experiment overcomes concerns about bias in other types of studies, the researchers said.

They also acknowledged weaknesses in the design of the study, such as how the participants volunteered. More than 90 per cent of the families participating were headed by a black or Hispanic woman.

"The mechanisms accounting for these associations remain unclear, but further investigation is warranted to provide guidance in designing neighborhood-level interventions to improve health," the study's authors concluded.

The study was funded by several U.S. government departments and foundations.

With files from CBC's Pauline Dakin