Your ZIP code matters

Although disparities between the health of rural residents and city dwellers is well studied, researchers are finding health and life expectancy differences between populations that are much closer in proximity—say, for instance, in neighboring ZIP codes.

A baby born in a ZIP code in the French Quarter of New Orleans has a life expectancy of 55 years. A few miles away, a baby born in a different ZIP code has a life expectancy of 80 years. In another example, two large cities in Texas, Austin and San Antonio, are just 80 miles apart, but San Antonio’s county is 78th in Texas on health outcomes of life expectancy and how healthy people feel, while Austin’s county is fifth.

Why the difference? It’s complicated.

“People think of health as a personal choice, but it’s not entirely,” said Jay Maddock, PhD, dean of the Texas A&M School of Public Health. “Health is multi-factored: it depends on genetics and behavior, and that behavior is greatly affected by someone’s environment.” This can mean an area’s natural environment—it’s easier to exercise outside in the winter in Texas, for example, than in Minnesota—but also the built environment.

The built environment—a neighborhood’s walkability, for example, or the existence of bike lanes or parks—plays a role, of course, but so does an area’s culture. Culture can greatly influence health behaviors such as smoking, alcohol consumption, drugs, nutrition and physical activity.

Because these are behaviors, they can be altered, but it’s not easy to do. Still, there are some techniques proven to help.

“When you talk about changing the culture of health, you have to model good behavior and do  things in schools like eliminating food as reward and physical activity as punishment,” Maddock said. “Institutions have potential to be agents of change for many populations. Universities in the Southeastern Conference—an area with generally poor health behaviors and outcomes—are working to help model healthy behaviors. It’s a good time for behavior change because those new habits might then be taken back to the students’ communities when they graduate and slowly have a ripple effect, leading to better health in their home ZIP codes.”

Although such behavioral change can help, there are some factors that are impossible for an individual to change unless they leave the environment entirely. For example, in neighborhoods where crime and violence are common, there are the obvious effects, but people might also be experiencing chronic stress and not be sleeping well—both of which can have negative health outcomes. Lack of safe places to play outside also affects health. “Fear causes parents to keep their kids inside, where they tend to sit and play video games rather than running around and playing,” Maddock said. “Sure, they are safe in the moment, but the long-term effects on their health can be huge.”

Unfortunately, living in neighborhoods with a high crime rate can be all some people can afford. “Affordable housing also tends to be in places with low access to grocery stores and higher access to fast food,” Maddock said. “Communities with easy, walkable access to amenities like grocery stores and entertainment venues tend to be desirable, which drives up the cost of the housing and prices out a lot of people.”

There are things that can be done on a policy level to help improve health behavior, but that requires political will or community action. For example, indoor smoking bans are effective at reducing cigarette use, Maddock said. “If it’s okay to smoke, people are going to smoke more,” he added. “We know that when smoking bans come in, people tend to quit. It’s just one example of how policy can make a big difference on people’s behavior.”

Such policy tends to be set at the local or even the state level, which may help explain why some states have better health outcomes than others.

“After accounting demographic characteristics like ethnicity, age and gender, there’s likely not something genetically different between people living in Colorado and Massachusetts, which have good health outcomes, and those living in Mississippi and Oklahoma, which do not,” Maddock said. “ZIP code is an influential predictor of overall health outcomes, so when working to improve the health of individuals, it’s also imperative to think about the environment that influences their behaviors.”