The United States spends more money on healthcare than any country in the world. Its hospitals lead in cancer treatment. Its laboratories develop breakthrough medicines. Its surgeons perform some of the most advanced procedures known to modern medicine. Yet a sweeping new international study suggests that millions of Americans are still dying earlier than people in other wealthy nations — and researchers say the gap is no longer small enough to ignore.

A major peer-reviewed analysis published on May 8, 2026, in JAMA Network Open found that the US recorded more than 12.6 million “excess deaths” between 1999 and 2022, compared with 17 other developed countries, including Japan, the United Kingdom, France, Germany, and Australia. In simple terms, researchers estimated that these Americans might have survived had the US achieved the same death rates as its peers.

The study, led by Jacob Bor and colleagues using data from the World Health Organization Mortality Database, paints a grim picture of a country struggling not with medical innovation, but with access, prevention and policy.

Researchers calculated that the US lost more than 314 million years of life over the 24-year period. That number becomes painfully real when viewed another way. It is equal to millions of parents, workers and young adults losing decades they otherwise might have lived.

“The US had substantially higher death rates than other high-income countries despite similar access to advanced medical technology,” the authors wrote.

Heart disease emerged as the biggest driver of the mortality gap. In 2022 alone, circulatory diseases accounted for nearly 359,000 excess American deaths — around 40 per cent of the total. US death rates from heart and blood vessel conditions were 1.63 times higher than those seen in comparable nations.

Researchers noticed something particularly worrying inside the data. Middle-aged Americans began showing worsening heart-related death trends nearly a decade earlier than older adults. Obesity, poor diet, inactivity and untreated high blood sugar appeared to be major contributors.

The diabetes and metabolic disease numbers were even more startling. Americans died from diabetes, kidney disease and related metabolic disorders at more than twice the rate seen in peer countries. Scientists linked this partly to what many public health experts now call “toxic food environments” — communities where cheap processed food is easier to access than healthier alternatives.

Then came the overdose crisis.

Deaths from drug poisonings in the US were found to be 7.48 times higher than in other wealthy nations in 2022. Researchers pointed to the spread of fentanyl, a powerful synthetic opioid, as a key turning point after 2013.

“No peer country experienced a remotely comparable pharmaceutical supply-chain catastrophe,” the report noted.

The study also highlighted what researchers increasingly describe as “deaths of despair” — fatalities linked to drugs, alcohol and suicide. Among Americans aged 25 to 44 years, these causes accounted for nearly half of excess deaths. Unlike Europe or Japan, the US has seen a sharp rise in premature deaths among working-age adults over the past two decades.

Gun violence stood out as another uniquely American crisis. US homicide death rates were more than 14 times higher than those recorded in comparable developed nations. Researchers argued the problem was not simply a crime issue but also a policy issue tied to firearm availability.

Ironically, the US still performs strongly in some areas. Survival rates for cancers such as breast, prostate and colorectal cancer remain among the best globally because of aggressive screening and advanced treatment systems. But experts say these successes are being overwhelmed by preventable chronic illnesses and social breakdown.

The COVID-19 pandemic widened every crack already present in the system. While the virus itself caused a large share of deaths, researchers found that heart disease, diabetes, addiction and mental health-related deaths also surged during the pandemic and failed to return to earlier levels afterwards.

What separates countries like Switzerland, the Netherlands and Canada from the US, the study suggests, is not better technology but stronger social protection. Most peer nations guarantee near-universal healthcare, invest more heavily in addiction treatment, regulate firearms more tightly and provide broader social safety nets for struggling families.

The findings arrive at a moment when healthcare costs in America continue to climb sharply, even as life expectancy trails behind much of the developed world.

For researchers, the conclusion was blunt. America’s missing millions are not disappearing because modern medicine failed. They are disappearing because many people never fully reach the benefits that medicine can offer.