I take this question to Thomas Frieden, New York’s commissioner of public health. Frieden is a wonk’s wonk—a handsome, energetic doctor who has gained a nationwide reputation for his aggressive effort to push New York’s average-life-expectancy figure ever higher. The smoking ban of 2003? The trans-fat ban of last year? You can thank Frieden for both. These measures have already begun to lengthen life spans in the city. The smoking ban had an immediate effect: The number of deaths attributable to smoking has decreased from 8,960 in 2001 to 8,096 in 2005, a drop of 10 percent. Lung-cancer rates should begin to see the same effect a few decades from now, since it takes longer for the body to repair smoking-related lung damage.
But even Frieden admits that public policy can’t account for all the gains. When I ask what the X factor is—where the “excess life” is coming from—Frieden 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. He’s got a bunch of them kicking around.
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. Indeed, the easiest way to tell a New Yorker from an out-of-towner is by walking speed: The natives blast down the sidewalk at blitzkrieg pace, and the visitors mosey along like pack mules. Eleanor Simonsick, a Baltimore-based epidemiologist, knew that regular walking is a powerful way to maintain your health. But she began to wonder, a question very germane to us in New York: Does the speed at which you walk also affect your health?
Researchers have long known New Yorkers walk faster than anyone else in the country. But epidemiologist Simonsick wondered, does walking speed affect health?
She decided to conduct an experiment to find out. She and a group of scientists assembled 3,075 seniors in their seventies and asked them to traverse a 400-meter course, walking as fast as they could. They monitored their subjects’ health over the next six years, during which time 430 of the geriatrics died and many more fell ill. When Simonsick crunched the data, she found that the ones who were dying and getting sick were the ones who walked the slowest. For every minute longer it took someone to complete the 400-meter walk, he had a 29 percent higher chance of mortality and a 52 percent greater chance of being disabled. People who walk faster live longer—and enjoy better health in their later years.
“Walking speed absolutely reflects health status,” Simonsick says. So when you irritatedly blow past a trio of ambling visitors from Ohio or Iowa on the subway platform, you’re not just being an obnoxious New Yorker. You’re demonstrating that you’re going to outlive them—and enjoy better health while they slowly degrade.
The thing is, as Simonsick points out, New York is literally designed to force people to walk, to climb stairs—and to do it quickly. Driving in the city is maddening, pushing us onto the sidewalks and up and down the stairs to the subways. What’s more, our social contract dictates that you should move your ass when you’re on the sidewalk, so as not to annoy your fellow walkers. (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.
This idea of the city as a health club is fairly revolutionary. Back in the beginning of the industrial revolution, cities were regarded, quite correctly, as lethal places to live. London and other newly ballooning industrial centers did not yet have sanitary or pollution laws, and the sudden influx of crammed-together citizens—living cheek by jowl with smoke-belching factories downtown—produced spectacular outbreaks of disease. Public-health experts somberly wrote about an “urban health penalty”—the idea that cities were dark, satanic mills that inherently cut us down in the prime of life. In the first decades of the twentieth century, cities began to clean up their acts drastically, when sanitation standards emerged and inoculations began to aggressively squelch infectious diseases; the actual life spans in cities began to catch up to and exceed those of people in rural areas. But the idea of urban rot remained strong, so the cultural bias against urban life lived on. It didn’t help when the seventies and eighties ushered in waves of urban crime, recession, and drug epidemics, and cities like New York and Detroit and Chicago sharply curtailed public-health services. Cities, more than ever, seemed like cesspools of dread and early death.