By Chris Adams

What has the biggest impact on people’s health?

It’s not what doctors tell them – not even close.

In fact, health care – what goes on in doctors’ offices and hospitals – only accounts for 20 percent of the reasons people die early. Instead, their behaviors, their genetic predispositions, social circumstances and environmental exposures make up 80 percent.

In a session with National Press Foundation fellows, Dr. Georges Benjamin, executive director of the American Public Health Association, laid out the causes of Americans’ poor health and ways it might improve if policies and spending priorities shifted.

“Access to health care is a small piece of the process,” Benjamin said. “Beyond that, place matters – your ZIP code matters. Smoking and how much we eat matters. Environmental things matter, like access to clean water. Where we dump our trash matters.”

Just consider what somebody’s ZIP code represents, Benjamin said. Where you live indicates your access to quality schools and safe housing; the availability of fresh food and outdoor play spaces; the prevalence of environmental toxins from highways or factories; and closeness to quality hospitals. It explains why rates of diseases – asthma, for example – vary widely within states, and from one neighborhood to the next.

He talked about life spans in Washington, D.C., where people who live at one end of the Red Line on the city’s Metro subway system live an average of 72 years; at the other end of that same subway, life expectancy is 81 years. (Data on other cities showing the same analysis by mass transit lines are available here.)

Of course, habits people develop also have a major impact – none more than smoking, which is the nation’s No. 1 preventable cause of death. And unhealthy eating plays a major role; some of that has to do with the prevalence of “food deserts,” or areas in big cities that aren’t supplied by the grocery chains that fill suburban stores with mounds of fresh, healthy food.

The science on all this is well-established, Benjamin said, and the public is beginning to recognize it as well.

“We’ve been trying educate people on this for 10 years, and they are finally getting it,” he said.