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THURSDAY, Aug. 28, 2003 (HealthDayNews) -- It's not just how you live that affects your health. It's also where you live.
People who live in sprawling areas where cars are required tend to weigh more and have higher blood pressure than those who live in more compact neighborhoods, says a new study in the September issue of the American Journal of Health Promotion.
"It's the first study to establish a direct link between urban sprawl, obesity and chronic health problems related to obesity and inactivity," says Reid Ewing, lead author of the study and a professor at the University of Maryland's National Center for Smart Growth.
The study is one of several on community design and health that are being published in special September issues of the American Journal of Health Promotion and the American Journal of Public Health.
"The emerging research in these two journals suggests that the environment plays a crucial role in perpetuating our country's lack of physical activity, skyrocketing obesity and related health problems," says Katherine Kraft, a senior program officer at the Robert Wood Johnson Foundation, who presided over a Thursday news conference at which the research was discussed.
"North Americans spend 90 percent of our time indoors. The places we live, work and play clearly affect our health," says Allen Dearry, associate director of the National Institute of Environmental Health Sciences.
"A number of chronic health conditions, including asthma and cardiovascular disease, are attributable to the interaction of environmental and genetic influences. Many of these environmental influences can be directly connected to the built environment," he adds.
Researchers hope these studies will be the beginning of a base of scientific knowledge that can be used to approach policy makers who have input into what types of communities are built.
About two-thirds of the U.S. population lives in metropolitan areas that were examined in the urban sprawl study, Ewing says. In all, the study authors looked at personal health information collected by the U.S. Centers for Disease Control and Prevention (CDC) on more than 200,000 people living in 448 U.S. counties in major metropolitan areas.
The researchers devised an index to assess the extent of sprawl in each county. Geauga County, near Cleveland, was the most spread out, with homes located far from shops, restaurants and other destinations. New York City's borough of Manhattan was the most compact county.
The typical person living in a compact area weighs, on average, six pounds less than someone living in a sprawling area. People in sprawling communities are also more likely to be obese and have high blood pressure, although there was not a statistically significant relationship between sprawl and diabetes, the study found.
The study also revealed that people in sprawling areas walk less, which may explain the other health findings.
"The weight may be the result of lower levels of physical activity, driving to work, driving to lunch, driving to school, basically driving everywhere," Ewing says.
So, what does the ideal community look like?
"Imagine a suburb around a light rail system or a bus station," says Michael Greenberg, associate editor of the American Journal of Public Health and associate dean at the Edward J. Bloustein School of Planning and Public Policy at Rutgers University.
"Instead of houses spread like peanut butter across the county, they are concentrated around a transit-oriented development," he says.
The ideal healthy, livable environment also would have sidewalks, bike lanes, individual corner stores along with a mix of different housing choices (detached, town houses) and fewer cul-de-sacs. Buildings would be close to the street, to create a more intimate feeling, experts say.
Would more sidewalks and grocery stories within walking distance of homes solve America's obesity crisis?
"We can't control for individual lifestyle choices or individual heredity," Ewing says. "That person sitting around the apartment eating potato chips is walking up and down stairs maybe, or walking to a bus stop and working off some of the extra calories he or she is taking in, but not all of them."
The link between obesity and environment was contested also by the National Association of Home Builders (NAHB) in Washington, D.C.
"There is no question that obesity is a serious health problem facing the United States. However, NAHB rejects the argument put forth in the SmartGrowth America report that the choices people make about where to live actually cause them to become obese. The study's findings simply do not support this contention," said Jerry Howard, CEO of the organization, in a prepared statement. "Where we do have common ground with the author is that we have long supported and advocated for activity-friendly design and higher-density residential development in or near developed areas. Too often, though, our efforts have been restricted by outdated zoning laws."
The latter point was echoed by Dr. Richard Jackson, director of the CDC's National Center for Environmental Health and guest editor of the September American Journal of Public Health.
There are several obstacles that have impeded progress, he says. "In many situations, old zoning codes are an obstacle to allow us to live, work and play in the same place. It's hard to find lenders when you mix [usages]."
For more on environment and health, visit the Centers for Disease Control and Prevention. You can read the urban sprawl report, titled Relationship between Urban Sprawl and Physical Activity, Obesity, and Morbidity, at Smart Growth America.