Lifestyle-linked diseases continue to increase globally
Diseases like cancer, heart disease and diabetes are becoming the dominant cause of death and disability globally, a landmark international study has revealed.
The change is driven by a boom in unhealthy lifestyles, with smoking and alcohol use leapfrogging child malnutrition over the last 20 years to become the second and third leading risk factors for disease, according to research published in The Lancet.
The study estimated the disease burden attributable to 43 risk factors in 1990 and 2010, and was undertaken by an international consortium of scientists as part of the Global Burden of Disease Study 2010.
The number of people dying or getting ill from infectious diseases, malnutrition or maternal and childhood illness has dramatically fallen over the past two decades, with the child death rate dropping each year.
But more young- and middle-aged adults are developing 'non-communicable' diseases such as cancer, fuelled by a rise in smoking, alcohol use and obesity.
"Overall we're seeing a growing burden of risk factors that lead to chronic diseases in adults, such as cancer, heart disease and diabetes, and a decreasing burden for risks associated with infectious diseases in children," Professor Majid Ezzati, one of the study's senior authors, said.
"The good news is there are lots of things we can do to reduce disease risk."
Sarah Williams, Cancer Research UK's health information officer, said the rise in cancer rates in developed countries was also linked to the growing, ageing population.
"The number of people dying from cancer globally has increased by more than a third since 1990, to around 8 million people in 2010. As cancer is generally a disease of old age, this increase is related to the growing global population and the rise in life expectancy," she said.
"There are more people in the world, and they're living for longer, but many of these deaths from cancer could be avoided."
The researchers estimated both the number of deaths and disability-adjusted life years (DALYs) - a unit that takes into account both years of life lost and years lived with disability - attributable to each risk factor.
"We looked at risk factors for which good data are available on how many people are exposed to the risks and how strong their effects are, so that our results can inform policy and programmatic choices," said associate professor Stephen Lim, of the University of Washington
Tobacco smoking, including the effects of second-hand smoke, was the biggest risk factor in western Europe and the wealthy North American nations, accounting for over 6 million deaths globally in 2010.
"The fact that tobacco smoking is so prevalent highlights the need for effective tobacco control policies like making smoking less attractive to children by banning the use of glitzy packs," said Williams.
Alcohol was also a huge cause of ill health, becoming the leading risk factor in Eastern Europe, most of Latin America and southern sub-Saharan Africa, and accounting for 4.9m deaths worldwide in 2010.
Alongside alcohol, added Williams, were factors like obesity, poor diet and lack of exercise.
"Alcohol use was also included in the top three risk factors globally, and was fourth most important for the Western European region, where it was pushed out of third place by overweight and obesity. Not getting much, or even any, physical activity and some factors relating to diet - particularly lack of fruit - were also among the top 10 for Western Europe," she said.
"People can cut the risk of cancer and other serious diseases by living a healthier life. And it's important to remember that the government and society have a hugely important role to play in creating an environment that supports healthier choices."
As well as identifying that rates of infectious diseases were being overtaken by non-communicable diseases, the study also showed that rates of premature deaths were dropping, to be replaced by chronic long-term disability.
Dr Richard Horton, editor of the Lancet, said the study "provided insights into human health that are comparable in scope and depth to the publishing of the human genome"
The GBD project is due to release country specific data in spring 2013. "It will be interesting to see how the UK compares to our neighbours," added Williams.
Copyright Press Association 2012
Global Burden of Disease Study 2010, Lancet (2012)