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The average life expectancy in the US has declined for a third straight year.

New research linked that decline to the fact that „working-age“ Americans, between ages 25 and 64, have been dying at higher rates.

These deaths have been linked to drug overdoses, suicides, and alcohol-related diseases, among other health problems.

Multiple experts agree that socioeconomic inequality and a economic hardship may have contributed to this increase in middle-age American deaths.

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The US is the only wealthy country in the world where the life expectancy needle is moving the wrong way.

Between 1959 and 2014, the average length of time that Americans were expected to live was on the rise. Now, for the third year in a row, it’s declining, according to a new study published in the Journal of the American Medical Association.

„Americans operate under a lot of misconceptions about how superior we are in many facets of our lives and this is not one of them,“ the study’s lead author Steven Woolf told Business Insider. „We may think we have best medical care in world and highest life expectancy … but that’s not the case.“

This decline can’t be linked to just one ethnicity, gender, or geographic area, either: It originates among an entire age group. People between the ages of 25 and 64 in the US are dying at higher rates, wracked by health problems like opioid addiction, obesity, alcoholic liver disease, and suicide.

Despite having the highest per capita health care spending in the world, Americans are „more likely to die before age 65 than people in other countries,“ Woolf added. „Their children, too, are less likely to live as long.“

A terrifying trend

Woolf and his co-author Heidi Schoomaker’s new study looked at more than 50 years‘ worth of data on US life expectancy from the US Mortality Database and the US Centers for Disease Control and Prevention’s WONDER database.

Results showed that, in the 1970s, the country experienced a rapid and significant jump in life expectancy. But by the 1990s, that increase started to level off.

In 2011, US life expectancy plateaued, and three years later it started to drop.

„We’ve reached the point where we’re going into a free fall,“ Woolf said.

Medical advances, particularly in the realms of cancer treatment and heart health, prompted an almost 10-year increase in the average American’s lifespan. Between 1959 and 2013, life expectancy rose from 69.9 years to 78.9 years. Now, however, that average has dropped to 78.6 years.

Actress/producer Nina Dobrev and Venture capatalist/polo player Omar Mangalji blow out their birthday candles at The Spare Room on January 20, 2017 in Hollywood, California. Rochelle Brodin/Getty

The news isn’t good if you compare it to other countries, either. In 1960, Americans had the highest life expectancy of any country in the world. But in the past couple of years, the US has plummeted to the bottom of the list of countries with a similar GDP and high average income, according to the Kaiser Family Foundation.

In fact, the US is currently ranked in the mid-40s globally in terms of life expectancy, squished between countries like Lebanon, Cuba, and Chile, which have GDPs that fall far short of our own.

That troubling dip, according to Woolf, can be linked to the fact that deaths among Americans ages 25 to 64 are increasing.

‚Working-age‘ Americans are dying

These deaths can’t be traced back to a single cause, either. Woolf’s research revealed that mortality among members of this age group has increased from 35 different causes. However, drug overdose, alcohol abuse, and suicide — referred to by some as „deaths of despair“ — appear to be the primary culprits.

This age group experienced a nearly four-fold increase in fatal drug overdoses between 1999 and 2017.

Suicide rates went up by nearly 40% for people between the ages of 25 and 64, and by 56% for people ages 55 to 64 during the same time frame. For Americans between the ages of 25 and 34, the rate of alcohol-related disease deaths spiked almost 160%, as well.

mbulance medics care for a man in his 40\'s who was found unresponsive after overdosing on an opioid in the Boston suburb of Salem, Massachusetts, on August 9, 2017. Brian Snyder/Reuters

Obesity-related mortality rates among this age group also went up by 114%, and deaths linked to high blood increased by about 80%.

„Working-age Americans are more likely to die in the prime of their lives,“ Woolf said. Between 2010 and 2017, midlife US adults experienced a 6% total increase in mortality rate.

The largest increases in death rates occurred among people living in New England states (middle-aged New Hampshirites saw a 23.3% uptick; Maine residents, 20.7%; Vermont dwellers, 19.9%) and residents of the Ohio Valley (West Virginians experienced a 23% increase and Ohioans, 21.6%).

Not all parts of the US experienced the same trend, however. Life expectancy between 2010 and 2017 increased for Americans living in Hawaii, California, and parts of the Pacific Northwest.

Flickr / Pabak Sarkar

All told, men are dying in overall higher numbers than women. However, Woolf’s research reveals that women experienced an greater increased risk of drug overdoses, suicides, and alcohol-related liver disease compared to previous decades.

„There’s an obvious implication of this for employers,“ Woolf said. „If this trend continues, they’re going to have a less healthy, less productive workforce that’s more likely to die prematurely compared to employees in other countries.“

Why is this happening when the US spends so much on healthcare?

This counterintuitive trend — of an affluent, first-world country that spends billions on privatized healthcare losing swaths of their middle-aged working class — could be traced back to one massive elephant in the room.

„It’s a quandary of why this is happening when we spend so much on healthcare,“ Woolf said, adding: „But my betting money is on the economy.“

The „Rust Belt,“ the Midwestern US states nearest to the Great Lakes like Ohio, were among the hardest hit by changes to the economy and related loss of factory jobs, the researcher said. „Steel mills and coal mines have been closing, while in contrast, California has done well in terms of its economics.“

Coal miner Jaden Fredrickson, 26, of Cheat Lake, West Virginia, waits for the arrival of U.S. Environmental Protection Agency Administrator Scott Pruitt who visited the Harvey Mine on April 13, 2017 in Sycamore, Pennsylvania. The Harvey Mine, owned by CNX Coal Resources, is part of the largest underground mining complexes in the United States. Justin Merriman/Getty Images

Upticks in suicides, drug overdoses, and alcohol-related diseases „are all symptoms of people struggling in a poor economy who can’t afford housing, find consistent jobs,“ and despair because of it, according to Woolf.

„We are seeing social determinants of health shaping well-being and outcomes,“ Howard Koh, a professor at the Harvard T.H. Chan School of public health who was not involved in the study, told Business Insider.

„Forces like income inequality and unstable employment cause psychological distress and drive conditions by which diseases and deaths occur,“ he added.

In countries around the world, research has shown that people with lower incomes die sooner than their wealthier counterparts. A 2017 study linked low socioeconomic status to significant reductions in life expectancy.

But what makes the US unique, according to Woolf, is that „poor people in other countries live longer than poor people in our country.“

The gap between America’s rich and poor has widened not only from a socioeconomic standpoint but also in terms of health inequality.

R.J. Taylor Memorial Hospital, Inc. Family Medicine Physician Dr. Albert Warren, MD consults with a patient and records the patient’s symptoms on an electronic tablet in Hawkinsville, Georgia on March 6, 2013. Bob Nichols/USDA

„The price you pay in terms of your health for not being on the top rung of the economic ladder is getting more dire,“ Woolf said.

According to Koh’s editorial commentary on the new study, the difference in life expectancy between America’s top and bottom 1% can be up to 14 years for men and 10 years for women.

‚A troubling new norm‘

„Everyone assumed life expectancy would continue to rise, but the nation now risks declining life expectancy to be a very troubling new norm,“ Koh said.

The only way to find out whether Koh’s prediction is true is by analyzing the most recent life expectancy data from 2018. Those numbers will be released by the CDC in the next few months, Woolf said. „But all signs from research we’ve done indicate it’s not going to be good news.“

And neither Woolf nor Koh think that the life expectancy situation will improve over time unless the underlying social and socioeconomic issues are adequately addressed. Woolf said state governments need to invest in marginalized communities and work to alleviate financial burdens on middle-class families.

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The Harvard researcher added that US policy-makers need to pay more attention to what he calls „leading causes of life,“ like building stronger communities that precipitate more vibrant social connections and help Americans rebuild a sense of purpose in the face of financial despair.

„The public health world is rapidly understanding that health is much more than what happens to you in a doctor’s office,“ Koh said. „It happens where people live, learn, play, and pray.“