By Brenda Goodman
WEDNESDAY, July 10 (HealthDay News) -- Life expectancy has increased in the United States over the last two decades, but Americans are also spending more of their lives in poor health, a sweeping new study finds.
And despite being the biggest spender on health care in the world, the United States lags behind many other prosperous countries in the leading causes of premature death, including heart disease, violence, traffic accidents and diabetes.
The main culprit behind the U.S. health problems appears to be eating habits, which are too low in fruits, vegetables, nuts and seeds, and too high in sodium, processed meats and trans fatty acids, according to the report.
The new study is the latest in a series of reports by the Global Burden of Disease Study, a collaboration of 488 researchers in 50 countries. The group is sifting through staggering amounts of information to learn how different countries compare when it comes to life expectancy and overall health.
The project is taking stock of early deaths and disability caused by 291 diseases and injuries around the world. It is also taking a country-by-country look at which risk factors make the biggest contributions to health problems. Reports on China and Great Britain were published earlier this year.
The findings on the United States were published online July 10 in the Journal of the American Medical Association. The White House and National Press Club also hosted separate events on Wednesday to announce the study findings.
"It's rare these days that you get information or studies that give you the big picture," said study author Dr. Christopher Murray, director of the Institute for Health Metrics and Evaluation at the University of Washington, in Seattle.
"It's pretty uncommon to step back and say, 'What does all the evidence tell us about the most important health problems, and where does the U.S. fit in that landscape?'" he said.
Murray said the United States has seen a shift in the last 20 years from illnesses that cut life short to chronic conditions that lead to longer-term disability. That means Americans are living longer on average, but they aren't necessarily spending those years in good health.
The biggest causes of early death in the United States continue to be heart disease, lung cancer, stroke, chronic obstructive pulmonary disease and road injuries, with little change in those killers over time.
The biggest causes of disability are low back pain, depression and other musculoskeletal disorders. Mental problems such as depression and anxiety now comprise about one quarter of all disability in the United States.
The study also found some bright spots. Thanks to powerful new medications, HIV and AIDS, which were the 11th leading causes of death and disability in 1990, dropped to 32 in 2010. Road injuries -- such as traffic accidents, once the fourth leading cause of death and disability -- now rank ninth. Birth defects are also taking less of a toll on health. They ranked 20th in 1990, but have dropped to 29th, thanks, in part, to mandatory fortification of grain products with folic acid, which has reduced the number of babies born with devastating neural tube defects, according to the report.
"We have been gradually improving over the last 20 years, but other countries have progressed even more rapidly, and our relative standing compared to other wealthy countries has actually declined," said Dr. Harvey Fineberg, president of the Institute of Medicine, who wrote an accompanying editorial on the study.
From 1990 to 2010, average life expectancy increased in the United States by three years -- from 75.2 years to 78.2 years for both sexes combined. But other prosperous countries saw larger gains over that period.
Ireland gained 5.1 more years, on average. South Korea gained 7.6 years of life expectancy on average. And life expectancy in Australia grew by an average of 4.6 years.
Murray said Australia makes an interesting comparison to the United States. Both are countries of immigrants with culturally diverse populations. Australia spends half as much as the United States on health care each year. Despite that, Australians are less likely to die prematurely or become disabled than Americans. They also have lower rates of major killers like heart disease, lung cancer, violence and diabetes, he noted.