Modern lives longer but more painful
The world has made huge progress fighting killer infectious diseases, but as a result we now lead longer and sicker lives, with health problems that cause us years of pain, disability and mental distress.
This "devastating irony", as researchers describe it, is the main conclusion of a five-year study that forms the most comprehensive assessment of global health in the history of medicine, according to the journal publishing the research.
The Global Burden of Disease study, led by the Institute for Health Metrics and Evaluation (IHME) at Washington University, finds that countries face a wave of financial and social costs from rising numbers of people living with disease and injury.
Among other findings are that while malnutrition has dropped down the rankings as a cause of death and illness, the effects of excessive eating are taking its place. Smoking and alcohol use have also overtaken child hunger to become the second and third leading health risks, behind high blood pressure.
Over three million deaths globally were attributable in 2010 to excess body weight, more than three times as many as malnutrition.
"We've gone from a world 20 years ago where people weren't getting enough to eat to a world now where too much food and unhealthy food - even in developing countries - is making us sick," said Majid Ezzati of Imperial College London, one of the lead researchers.
However, the major health problems now are diseases and conditions that don't kill, but make us ill. We now live longer with more health problems that cause pain, impair mobility, and prevent us seeing, hearing and thinking clearly.
"Very few people are walking around with perfect health, and as people age, they accumulate health conditions," said Christopher Murray, the IHME's director. "This means we should recalibrate what life will be like for us in our 70s and 80s. It also has profound implications for health systems as they set priorities."
The study, as the largest systematic effort to quantify world health levels and trends, involved more than 480 researchers from 302 institutions and 50 countries. It was funded by the Bill & Melinda Gates Foundation and published as seven papers in The Lancet medical journal on Thursday.
Experts compared the study's scope and importance for future health and medical research with the vast project to map the human genome in the late 1990s and early 2000s.
"It's that kind of order of magnitude that we're talking about here," said Peter Piot, a professor of public health and director of the London School of Hygiene & Tropical Medicine.
"This is the most comprehensive assessment of human health in the history of medicine," Richard Horton, editor of The Lancet, told reporters. "(It) provides the foundation for an urgent review of current priorities in health."
The research found that of 52.8 million deaths globally in 2010, chronic diseases took the highest tolls. About 12.9 million deaths were due to stroke and heart disease - conditions exacerbated by eating and drinking too much, smoking and taking too little exercise - and eight million were from cancer.
HIV/AIDS killed 1.5 million people in 2010, and tuberculosis, another infectious disease, killed 1.2 million.
While child mortality has decreased, there has also been a startling 44 percent increase in the number of deaths among adults aged 15 to 49 between 1970 and 2010. This is partly because of increases in violence such as homicide and traffic accidents and the AIDS epidemic, the researchers said.