Habitat matters -- 'Walkable' communities may make elders healthier

February 12, 2007

Some of a neighborhood's features -- the length of its blocks, how many grocery stores or restaurants are nearby -- may be more than selling points for real estate agents. A new study suggests such factors may work to beat back obesity in older people by increasing a neighborhood's "walkability."

The findings by University of Washington and Group Health Cooperative researchers involved more than 900 elderly Group Health members living in Seattle and King County. The results could have broad implications for public health and planning officials throughout the United States, where obesity has been called an epidemic and as baby boomers start to retire.

"The area around someone's home is an opportunity to walk if the habitat is right," said Dr. Ethan Berke, lead researcher of the study published in the March issue of the American Journal of Public Health.

Researchers compared the study participants' self-reported walking behavior with geographic information relating to the location of their residences, as well as some 200 directly observable neighborhood attributes, including parks, streets and foot-and-bike trails, land slope and traffic. Researchers concluded that the chief factors contributing to an area's walkability were higher residential density and clusters of destinations such as grocery stores, restaurants and other services.

Seattle's Maple Leaf, Capitol Hill and Ballard neighborhoods were considered more walkable, for example, than parts of Crown Hill, Burien, and other suburban areas where an attractive retail mix was farther from the study participants' residences.

But Berke said it would be a mistake either to embrace or reject entire neighborhoods or cities based on the research, because the focus was always defined by the area immediately around a person's home where they would be expected to walk as opposed to official neighborhood boundaries.

At the time of the study, which took place over a three-year period, Berke was with the UW's department of family medicine. He is now at Dartmouth Medical School.

Dr. Eric Larson, executive director of Group Health's Center for Health Studies and a co-author of the study, said the research shows you "have a higher chance of walking for exercise - from 30 percent to 600 percent in some comparisons - when you live in a more walkable neighborhood."

"And you may also be more likely to find yourself with people who are walking so it can be, or become, a social phenomenon," he added.

Larson called the findings "potentially important at the public health level when looking at the obesity epidemic and the epidemic of inactivity coming down the pike. The results suggest that as a society, we'd be better if we had more of these kinds of (walkable) neighborhoods."

Berke said the data suggest that habitat differences appear to make a difference for both older men and older women, though the effect seems more significant for the former. The study's 936 participants ranged in age from 65 to 97, with a median age of 78. About 63 percent were classified as overweight or obese.

The authors conceded they could not say categorically that increased walking reduces obesity, but also noted that physical activity is believed to be an important factor for health and weight control. Berke called on other researchers to replicate the study elsewhere to see if they reach similar results, or if the Seattle area is unique.

Source: University of Washington