Chronic diseases take a toll on U.S. life expectancy

Americans' life expectancy has been stagnant for over a decade, and much of the blame has been placed on "deaths of despair" among middle-aged adults.

But a new study suggests that chronic disease among older Americans is actually the biggest factor.

After a century of steady improvement, Americans' life-expectancy gains nearly ground to a halt starting around 2010.

By 2019, average life expectancy for a newborn in the United States was just under 79 years, according to the U.S. Centers for Disease and Prevention. That was barely any different from the outlook in 2010 -- a striking reversal of previous trends.

Since 1900, U.S. life expectancy had grown by nearly three years, on average, each decade.

Research into the "why" has often focused on troubling trends among working-age adults: More middle-aged Americans, particularly those with less education, have been dying of drug overdose, alcohol abuse and suicide -- what some researchers term deaths of despair.

But while that issue captures headlines, another trend has taken shape at the same time.

A 2020 study found that stalled progress against cardiovascular disease -- including heart attacks and stroke -- has actually had a bigger impact on U.S. life expectancy since 2010.

"We found a slowing decline in [heart-related death rates] that outweighed the increase in drug-related deaths," said researcher Leah Abrams, an assistant professor of community health at Tufts University in Medford, Mass.

That, she said, raised the question of what might be going on among Americans of different ages: Older adults suffer heart disease at a higher rate than younger people, so it made sense that deaths among older Americans might have an underappreciated role in the decline in U.S. life expectancy.

In the new study, Abrams and her colleagues found just that.

Between 2000 and 2009, Americans' average life expectancy at age 25 grew by about 1.4 years for women and 1.7 years for men. From 2010 to 2019, those gains were greatly reduced -- to just 0.4 and 0.17 years, respectively.

Meanwhile, death rates among 65- to 84-year-old Americans showed a similar pattern -- declining at a slower pace between 2010 and 2019, compared to the previous decade.

Had that not happened, Abrams and her colleagues estimate, U.S. life expectancy would have kept growing, by about a year.

Experts said the findings -- published Monday in the Proceedings of the National Academy of Sciences -- do not discount the impact of those tragic, preventable deaths of despair.

But chronic health conditions like heart disease -- long the No. 1 killer of Americans -- are simply far more prevalent, Abrams said. So even a slowdown in progress against those ills has a major impact on U.S. life expectancy.

Why has that progress stalled out? This study cannot answer that, Abrams said.

But she and other experts pointed to some strong suspects: a rise in disease risk factors like obesity and physical inactivity; social factors, like problems accessing healthy, affordable food and stable housing; social isolation and loneliness among Americans in general and older adults in particular; a fraying social safety net for seniors; and a flawed healthcare system.

"Life expectancy is determined by both healthcare delivery and things that happen outside of the healthcare system," said David Radley, who studies health system performance at the nonprofit Commonwealth Fund in New York City.

In a recent analysis, he and his colleagues found that Americans -- regardless of which state they live in -- typically die younger than people in similarly wealthy countries, including Canada, Japan and much of Europe.

The reasons, he said, are probably varied, but an obvious difference is that those countries have universal healthcare and typically place a premium on primary care.

The United States, Radley noted, invests more in specialist care, where the focus is on treating disease rather than prevention.

"We need to do a better job of building a strong primary care system," Radley said.

Dr. Asaf Bitton, a physician and researcher with Harvard Medical School/Brigham and Women's Hospital, agreed.

"We do 'sick care' very well, if you have health insurance," Bitton said. Where the U.S. often falls flat, he added, is in health promotion and disease prevention.

In a 2021 study, Bitton and his colleagues found a clear relationship between local availability of primary care providers and life expectancy. Americans living in counties with few providers -- less than one doctor per 3,500 residents -- had an average life expectancy that was nearly one year shorter than that of people living in counties with more providers.

Unfortunately, Bitton said, the national shortage of primary care providers has only gotten worse with the pandemic.

The pandemic has also taken a further toll on U.S. life expectancy -- something this study does not capture, Abrams said. And older Americans, she added, have borne the brunt of COVID-19 deaths.

According to the CDC, U.S. life expectancy dropped to 76 years in 2021, its lowest level since 1996.

More information

Peterson-KFF has more on Americans' life expectancy.