THURSDAY, Nov. 10, 2016 (HealthDay News) -- The level of "well-being" in a community -- including people's emotional health and life satisfaction -- may help explain some of the disparities in life expectancy across the United States, a new study finds.

It's known that Americans' life expectancy can vary hugely depending on where they live. A 2013 study, for example, found that a male born in Fairfax County, Va., could expect to live almost 18 years longer than his counterpart born in McDowell County, W.Va.

Differences in demographics, including income, education and race, only partly explain the disparities.

The new study, published in the journal Health Affairs, looked at how the "well-being" of a county fits into the picture.

Well-being included the general physical health of a county's population. But it also measured people's levels of emotional health, life satisfaction, optimism and security -- whether they felt safe and had access to housing and health care.

It turned out that counties' well-being scores were linked to life expectancy, beyond factors such as poverty, education and race.

"We see this substantial variation in life expectancy in the U.S., and it's not just determined by socio-demographic factors," said lead researcher Dr. Anita Arora. She's a Robert Wood Johnson Foundation clinical scholar at Yale University.

"It's also how people feel, how happy they are, whether they have basic access to things like safe housing," Arora said.

All of those factors could ultimately affect people's life expectancy in many ways, she noted. If people live in areas with no places for them to exercise or buy healthy food, for example, it's hard to follow the healthy lifestyle advice they hear all the time.

A researcher not involved in the study agreed.

Most people probably understand the need to make healthy choices, said Laudan Aron, a senior fellow who studies social welfare issues at the Urban Institute in Washington, D.C.

"But the things health professionals ask people to do may not be practical for them to implement," she said.

"The steps that can improve health and well-being do not only play out at the individual level," Aron said. "There's a collective responsibility, too."

For the study, Arora's team used data from a nationally representative telephone survey of U.S. adults in over 3,000 counties.

Each county was given a well-being score based on residents' responses to questions about physical and emotional health, lifestyle habits, work environment, life satisfaction and "basic access" issues -- such as having affordable housing and health care, and a safe environment.

The average life expectancy in different counties varied widely, the study found: from about 73 to 85 years for women, and from roughly 64 to 82 years for men.

And there was a direct correlation between how a county's well-being score rose and people's life expectancy -- regardless of the area's racial makeup and poverty and education levels.

For every 1 standard deviation (4.2-point) increase in the county's well-being score, Arora said, life expectancy rose by almost two years for women, and by 2.6 years for men.

The findings are not surprising, according to Noreen Goldman, a professor of demography and public affairs at Princeton University.

"We know that for individuals, these same factors are related to life expectancy," said Goldman, who was not involved in the study.

What's not clear, she said, is this: "Does where you live matter over and above your individual characteristics?"

Arora acknowledged that her study does not answer that question. At the same time, she said, it's easy to see how a community can either limit or support people's ability to be healthy physically and otherwise.

Another study published in the same journal issue hints that community efforts can make a difference in residents' life expectancy.

Looking at 16 years of data, researchers from the University of Kentucky College of Public Health found that "preventable deaths" declined in U.S. communities that created health-promoting programs. Preventable deaths included infant deaths and deaths linked to conditions such as heart disease, diabetes and flu infection.

Specifically, officials in those communities worked with local organizations -- from hospitals to employers to faith-based groups -- to design programs that address local health issues, such as high rates of smoking or heart disease risk factors.

According to Arora, it's important to remember that "health" is not just about physical disease.

"The World Health Organization defines 'health' as a state of complete physical, mental and social well-being," she said.

So efforts to improve Americans' health and longevity have to go beyond the health care system, Arora said.

Aron agreed. She said that everything from investments in schools, to local tax policies and zoning laws, to efforts to improve neighborhood safety, can all ultimately affect people's health.

"We need to see the connections between all of these things and well-being," Aron said.

More information

The U.S. Centers for Disease Control and Prevention has more on healthy living.