How Cities Impact Health

The complex influence urban features have on health

Published on February 17, 2014by Tim Paul

When the influential urban thinker Jane Jacobs wandered the streets of New York’s West Village in the 1950s, she recognized the vitality of the city in its chaotic sidewalks and stores—a notion that upended the orthodoxy of city planners who prized order and efficiency. Today’s urban health researchers carry on that tradition, honing in on aspects of urban life that shape our health, and in doing so, challenging conventional thinking.

In a January 28 presentation, the first in a new Urban Health Conversations series, Dr. Gina Lovasi, an assistant professor of epidemiology at Columbia University’s Mailman School of Public Health, mapped out current thinking in urban health and invited the audience to add to the discussion. As a member of the School’s research group on the built environment and health, Dr. Lovasi examines the health impact of urban features from green space to fast food restaurants, often uncovering surprises.

urban health runners

One fertile area of inquiry is the recent large-swath transformation of New York City through the policy of “upzoning” neighborhoods to promote greater density, giving more people access to bike lanes and mass transit. “Creating new buildings may not be an obvious choice to improve health,” said Lovasi, but “getting people to move throughout their day is an important priority.”

Some at the talk questioned whether all density is created equal. Dr. James Colgrove, associate professor of sociomedical sciences at the Mailman School, pointed to the Barclays Center in Brooklyn and luxury development in Manhattan. “I’m not sure how bringing high-rise condominiums to Tribeca is going to increase the health of populations who are most in need,” Dr. Colgrove said.

Gentrification was another concern. Investments in the built environment could be detrimental to people who are forced to move as their rents skyrocket, noted Dr. Diana Hernandez, assistant professor of sociomedical sciences at the Mailman School. Dr. Lovasi agreed, noting, that many people in rezoned areas resist the changes. “There is tension between improving facilities and potentially displacing some of that population if there is a market response that values those improvements.”

Further clouding the picture: these interventions don’t work for everyone. Dr. Lovasi cited studies showing neighborhood density and proximity to mass transit encourages walking and cycling and is linked with healthier weights, but noted that associations suggesting a potential benefit were strongest among the educated and affluent. “Interventions to make neighborhoods more walkable may not work in disadvantaged groups,” said Dr. Lovasi. For those groups, safety concerns may be more salient as barriers to walking than the built environment.

Related outcomes were seen in a study of trees. Working with colleagues at the Columbia Center for Children’s Environmental Health, Dr. Lovasi set out to measure the health benefits of a city initiative to plant trees in low-income areas. The expectation was improved air quality and less asthma. Instead they found asthma rates were steady in children who lived near a tree canopy, but they had more tree pollen allergies. “It may be that we need to be more strategic in how we go about tree planting,” Dr. Lovasi said. “It’s a cautionary tale pointing us to unintended side-effects of interventions envisioned as health promoting.”

urban health Vietnam KFC

A Kentucky Fried Chicken in Vietnam

The tree study also serves as an example of how urban research could reshape policy. Selecting tree species that are less allergenic could help maximize the health benefits of massive tree planting campaigns like MillionTreesNYC.

Another line of research has looked at whether living near a lot of fast food restaurants makes people more obese. Surprisingly some studies have seen the opposite, where proximity to fast food restaurants is associated with healthier weights. How is this possible? One explanation points to the underlying level of commercial investment as a driver for both restaurant locations and a healthier lifestyle. “We looked at whether having banks and credit unions nearby predicted lower BMI, and it did,” said Dr. Lovasi.

Singling out fast food restaurants is also a challenge for researchers since calorie-dense foods are available everywhere from bodegas to pharmacies. Supermarkets on the other hand may turn out to be the superheroes of the urban environment, lowering rates of obesity.

urban health favela

a favela in Rio de Janeiro

Jane Jacobs, who is one of Dr. Lovasi’s favorite writers, wrote that every city is distinct and has its own stories to tell. This spring, Dr. Lovasi will travel to Rio de Janeiro to spend time in the favelas to learn from communities that grow organically and make decisions for themselves. “There is a tension between wanting to design perfect, completely formed communities that support health, and letting communities change in a way that serves the needs of the population,” she said.

In thinking about ways to shape urban health, it’s important to realize that cities aren’t made to create health. “Cities aren’t a pharmaceutical or healthcare intervention,” said Dr. Lovasi. Interventions must mesh with the larger goals of urban life. Doing so may require thinking about co-benefits and tri-benefits. For example, lowering reliance on automobiles has benefits for health, the environment and the economy. “I think we need to do a much better job at monetizing those impacts,” added Dr. Frederica Perera director of the Columbia Center for Children’s Environmental Health.

On the other hand, health may hold a special place as a prerequisite and starting point for everything else.  “When you don’t have health, it stands in the way of other goals,” said Dr. Lovasi. “Making cities more supportive of health is making cities more supportive of people.”

The second in the Urban Health Conversations series, on March 25, will be led by Dr. Mindy Fullilove, professor of sociomedical sciences at the Mailman School and author of a recent book on urban design. Future speakers will engage issues in urban health through the perspective of the environment, history, human rights, and ethics. The full schedule of talks is online.

This article originally appeared on the Mailman School of Public Health website.