FRIDAY, Nov. 22, 2024 (HealthDay News) -- How long Americans can expect to live varies dramatically -- and the gap continues to widen.

A new report says health inequalities have, in essence, created 10 Americas.

These mutually exclusive populations are divided along familiar fault lines, including race, ethnicity, income and address. 

While life expectancy rose in nine of 10 Americas between 2000 and 2010, only six saw gains between 2010 and 2019, according to the report. 

And it plummeted in all 10 in 2021, the first year of the pandemic.

In 2021, Asian Americans had the longest life expectancy at birth -- 84 years. 

That's two decades more than the group with the lowest life expectancy: American Indians and Alaska Natives living in the West, who were expected to live 63.6 years. 

"The extent and magnitude of health disparities in American society are truly alarming in a country with the wealth and resources of the USA," said Christopher Murray, director of the University of Washington's Institute for Health Metrics and Evaluation. "These disparities reflect the unequal and unjust distribution of resources and opportunities that have profound consequences on well-being and longevity, especially in marginalized populations."

Murray is senior author of the report, which was published Nov. 21 in The Lancet, a British health journal.

It builds on an earlier study that identified "Eight Americas" based on race, geography, ethnicity, per capital income and homicide rate. 

Authors of the new report noted that life expectancy is considered a key measure of a population's health. 

Across the 10 Americas, the gap rose from 12.6 years in 2000 to 20.4 years in 2021, fueled largely by the pandemic, the report said. 

American Indian and Alaska Native people in the West, who already had the shortest lifespan, were the only group to experience large drops in life expectancy before the pandemic. 

Between 2019 to 2021, they lost another 6.6 years. 

Meanwhile, progress to improve life expectancy among Black Americans has largely stalled, the report showed.

Those living in poor, rural counties in the South or in highly segregated cities had the lowest life expectancy in 2000 -- about 70.5 years -- while Asian Americans had the highest, 83.1 years. 

Between 2000 and 2010, Black Americans saw some of the largest gains, with their life expectancy rising by as much as 3.7 years. 

"The gap between life expectancy at birth for Black and White Americans may never have been narrower than it was in the mid-2010s," said study co-author Thomas Bollyky, of the Council for Foreign Relations. 

"It's likely that long-term improvements in education available to Black children and young adults in recent decades, as well as reductions in homicide rates and deaths from HIV/AIDS -- causes of death that have disproportionately impacted Black Americans -- may have contributed to these noteworthy gains for Black Americans," he added in a journal news release.

But those gains -- as well as those in all the other Americas -- largely ended between 2010 and 2019, researchers found. The contributors included homicides, drug overdoses and a slowdown in reducing heart-related deaths, often linked to obesity.

"More research is needed to fully understand why life expectancy is worse for some Americans, so we can better tackle the root causes of poor health for the most disadvantaged," said study co-author Ali Mokdad, of the University of Washington.

The findings suggest that differences in education and income account for some of the gap. American Indian and Alaskan Native people have shorter lives, researchers suspect, due to chronic underfunding of Indigenous health services, poor access to care and low rates of educational attainment. As a result, they die at higher rates from preventable causes like smoking, chronic disease, drug overdoses and COVID.

Researchers called for federal, state and local governments to work together to close the gaps. Prioritizing healthcare, educational and job development resources to address the root causes is key, they added.

"Policymakers must take collective action to invest in equitable health care, education and employment opportunities and challenge the systemic barriers that create and perpetuate these inequities so that all Americans can live long, healthy lives, regardless of where they live and their race, ethnicity or income," Murray said.

More information

The U.S. Centers for Disease Control and Prevention has more about life expectancy in the United States.

SOURCE: The Lancet, news release, Nov. 19, 2024