Lynda Stratford walks 10,000 steps a day — she knows this from the electronic Jawbone device that she wears on her wrist that counts her steps.
She walks her son a mile to kindergarten every day, pushing her 2-year-old in a stroller. In fact, Stratford's family doesn't own a car, so any time she goes anywhere — like, say, Trader Joe's where she likes to get groceries — it's a combination of walking, stairs and sometimes the stairs that lead to and from the subway.
Stratford and her family live in Manhattan, and like many urban dwellers, they are used to life on foot. Eighty-two percent of Manhattanites travel to work by public transit, bike or by walking, which is 10 times the national average. All of these steps add up, according to new research, which links urban living to lower levels of obesity and longer life spans.
But the advantages of urban living — and disadvantages of suburban sprawl — go beyond health benefits. The research from Smart Growth America and the University of Utah's Metropolitan Urban Center also show that the high-density, high-diversity climate of urban centers can give city kids and adults a better chance of getting ahead.
"Urban places provide higher likelihood of moving up the social ladder," says Reid Ewing, professor of city and metropolitan planning at the University of Utah and the lead researcher. "Compact places provide better access to jobs, better transit and more integration."
Inner cities are often linked to poverty and intergenerational struggles, but that's not necessarily true, according to the study findings. Researchers found that compact areas linked by public transit can help low-income kids get ahead financially as grown-ups. A child in a dense area born in the bottom 20 percent of the income scale has a better chance of rising to the top 20 percent by the age of 30, Ewing says.
A child in relatively dense Los Angeles, for example, has a 10 percent chance of moving from the bottom income bracket to the top, while a child in Atlanta — one of the most sprawling places in the country — has only a 4 percent chance.
There are several possible explanations for this, says Ewing, and one is transportation. In sprawling suburbs, housing and commerce centers are often far apart and public transit sparse, which makes it hard for people to get to work or get access to good jobs. Low-income people usually have fewer transportation options, or struggle to afford that mainstay of American suburban transportation — a private car, says Ewing.
"People living in more compact places have shorter commutes to work," he says. "Picture a place with a dense mix of residential and business development, with interconnected streets and transportation, that gives better access to all sorts of things — but especially jobs. Then think of a really sprawling place like Atlanta, how auto dependent and isolated neighborhoods are."
Another factor may be better income and race integration in cities, says Shima Hamidi, who co-authored the study. "In dense areas, there are more chances for networking, for meeting people, more chances of getting better salaries and jobs." High-income parents demand better schools, for example, says Ewing, so in integrated areas the lower-income kids have a better chance of attending those good schools, too.
There is also growing evidence that living among strip malls and far-flung housing developments can be bad for health. People in dense urban areas tend to be thinner and have lower incidence of diabetes and heart disease.
Once again, car use is a culprit. According to a study in The American Journal of Preventative Medicine, train riders are 6.5 pounds lighter than others, and 81 percent less likely to become obese over time.
"More sprawl is less walking and reduced physical activity," says David Berrigan, program director at the National Cancer Institute. "That can have powerful health consequences because physical activity is very beneficial for preventing obesity, diabetes and cancer."
The study examined residents in Charlotte, N.C., after a new high-tech light rail system was installed in 2007. Their findings were that riding the rails led to more walking by an average of 1.2 miles a day.
Still, it's not as easy as moving into a townhouse and walking your way to health. Berrigan, who wasn't involved with the study but has done his own research on health and environment, says that race, income, behavior and other factors also play a role.
"It's not as simple as city good, suburbs bad," he says. "People at different times have demonized suburbs or cities — the suburbs are known for sloth and automobiles, cities for crime and pollution."
The research paints a more nuanced picture, he says. For example, children get more physical activity in the suburbs with cul-de-sacs and yards, and adults get more activity in the city where they don't hop into a car all the time.
Lynda Stratford has been living in Manhattan for almost four years, but previously she lived in Hong Kong. There, she says, the public transportation is much cleaner and efficient — train stations are like gleaming shopping malls. New York's subway, by comparison, is dank and dirty, she says, and Hong Kong has clever solutions like outdoor escalators that take commuters up and down the city's steep hills. If the United States invested more in public transport, she says, it's more likely that Americans would use it.
President Obama recently asked Congress for a major transportation overhaul that would put $50 billion into infrastructure, including 4,000 miles of rail tracks. Still, there are other changes that communities can make, says Berrigan. One of his favorites is community bike-share programs. "People thought that would only work in big, flat cities like New York, but it's been instituted in Rockville, Md., a midsized suburban town. People are seeing what's possible — they're fostering creative, active transport."
Ewing says that trying to get everyone to adjust to apartment living is not the answer — but he would like people to have more options. "We are not arguing — and this is important — that everyone should live in the city. But people should have the choice to live in more mixed-use areas."
Berrigan imagines a public health movement like the sanitation and health services that swept American cities in the late 1800's, this time with an eye toward built environments and transportation. "It's time to ask the question again," he says, "how can we make cities better?"