A recent article in New York magazine by Clive Thompson called "Why New Yorkers Last Longer" pulls together some intriguing facts that anyone interested in walkable, mixed use, mixed income communities should consider. The article, as the title suggests, explores why the "average life expectancy" of New Yorkers has grown faster than that of the U.S. as a whole, especially in since 1990. Now it is 78.6, while the national average is 77.9; as recently as 1990, the average life expectancy of a New Yorker was three years shorter than the national average.
Certain factors may be unique to New York, such as the drop in the crime rate (New York is now the safest city in the U.S.) and new drugs that have extended the life of AIDS patients. But other factors are more generic to all urbanized areas.
Here are some excerpts:
Walking
"When I ask what the X factor is -- where the 'excess life' is coming from -- Frieden [Thomas Frieden, New York's commissioner of public health] goes over to his desk and returns with a clear plastic statuette. It's from the American Podiatric Medical Association and Prevention magazine: BEST WALKING CITY, 2006.
"'We've won it a couple of years in a row,' he tells me with a grin.
"Walking? This isn't quite as facile an explanation as it sounds. Scientists who study urban health argue that it's not just that we walk more -- it's the way we walk that has a surprising spillover effect on life spans. Researchers have long known that people here walked fast -- far faster than anyone else in the country....
"'Walking speed absolutely reflects health status,' Simonsick [Eleanor Simonsick, a Baltimore-based epidemiologist] says....
"...(A recent ranking of cities found that New York has the fastest pedestrians in the country.) As Simonsick sees it, the very structure of the city coerces us to exercise far more than people elsewhere in the U.S., in a way that is strongly correlated with a far-better life expectancy. Every city block doubles as a racewalking track, every subway station, a StairMaster. Seen this way, the whole city looks like a massive exercise machine dedicated to improving our health while we run errands."
Driving
"Three years ago, Lawrence Frank, a professor of urban planning at the University of British Columbia, set out to measure this effect, examining 10,858 people in Atlanta and the type of neighborhood they lived in. Some were in purely residential suburban neighborhoods, where you had to get in your car to buy a carton of milk; others lived in 'mixed' downtown areas with shops within walking distance. When he checked the results, the health difference was shockingly large: A white man who lived in a more urban, mixed-use area was fully ten pounds lighter than a demographically identical guy who lived in a sprawling suburb.
"'The more you drive, the more you weigh,' Frank [says]."
Other factors
Thompson goes on to list other factors, such as studies that show that people who live in interesting areas walk more, an intuitively obvious result, but studied nonetheless by the NIH:
"A 2002 study by the National Institutes of Health found that people living in buildings built before 1973 were significantly more likely to walk one-mile distances than those living in areas with newer architecture -- because their environments were less architecturally ugly."
It does make a difference whether the streetscape has an inviting mix of store fronts and buildings rather than parking lots and parking garages, a streetscape seemingly designed to keep people off the sidewalks and in their cars.
And density adds yet other benefits, as Thompson reports:
"When you're jammed, sardinelike, up against your neighbors, it's not hard to find a community of people who support you -- friends or ethnic peers -- and this strongly correlates with better health and a longer life. Then there are economies of scale: A big city has bigger hospitals that can afford better equipment -- the future of medicine arrives here first. We also tend to enjoy healthier food options, since demanding foodies (vegetarians and the like) are aggregated in one place, making it a mecca for farm-fresh produce and top-quality fish, chicken, and beef. There's also a richer cultural scene than in a small town, which helps keep people out and about and thus mentally stimulated."
An added and unexpected benefit is that of gentrification -- assuming that lower income families who have lived in a neighborhood for years are not driven out by an influx of wealthier households. Mixed income communites bring health benefits to the poor as well as the rich.
"One study by Ming Wen, a sociologist at the University of Utah, crunched data on 8,782 residents of various neighborhoods in Chicago. She expected to find the typical bleeding-heart conclusion: Poverty is bad, income inequality is bad, and the two together are worse yet. But in reality, income inequality at the neighborhood level paradoxically seemed to mitigate the bad effects of poverty. In neighborhoods that mixed affluent people alongside poor ones, the poorer residents were statistically healthier than those in non-mixed neighborhoods.
"That's because, Wen concluded, the presence of relatively wealthy people has a spillover effect on the immediate neighborhood: safer streets, cleaner environments, better food in stores. (Indeed, another study found that poor teenagers in mixed-income neighborhoods ate more leafy green vegetables than poor teenagers in non-mixed ones.) Wen is careful not to say that all income equality produces trickle-down effects; if the poor and wealthy are completely sealed off from each other in different parts of a city, the effect doesn't occur."
The Chicken and Egg Problem
Matthew Turner, an economist at the University of Toronto, demurs. He believes that people who are healthy and like to walk gravitate towards cities while those who are heavier and so like to drive find their way to the suburbs where driving is the norm. In his view, cities are healthier due to this self selction by healthier people. This may be true, but it does not deny the value of density, attractively designed streets and buildings, and the other benefits density brings to the rich and the poor alike.
Well designed, compact urban areas surely attract a certain kind of person, young up and comers, older people who like the urban energy. On the other hand, there are all the people who have been living in urban areas for decades because it is where their jobs, families, friends, and communities are (and for some because they could not afford to move to the suburbs after the Fair Housing Laws opened them up to people of color).
Whether cities attract the healthy or make those who live their healthy, or both, the important thing to know is that city living is healthier than either suburban living or rural living. Which is a radical turnaround from 100 years ago when cities were seen as dens of illness and inequity.
