Smoking, high blood pressure and being overweight-these are the top three preventable risk factors for premature mortality in the United States, according to a new study.
Led by researchers at the Harvard School of Public Health (HSPH), the collaborative study found that smoking is responsible for 467,000 premature deaths each year, high blood pressure for 395,000, and being overweight for 216,000.
The effects of smoking work out to be about one in five deaths in American adults, while high blood pressure is responsible for one in six deaths.
The study is the most comprehensive analysis till date, which looked at how diet, lifestyle and metabolic risk factors for chronic disease contribute to mortality in the U.S.
"The large magnitude of the numbers for many of these risks made us pause. To have hundreds of thousands of premature deaths caused by these modifiable risk factors is shocking and should motivate a serious look at whether our public health system has sufficient capacity to implement interventions and whether it is currently focusing on the right set of interventions," said Goodarz Danaei, a doctoral student at HSPH and the lead author of the study.
Also, the researchers found large effects from a series of other preventable dietary and lifestyle risk factors.
All of the deaths calculated in the study were considered premature or preventable in that the victims would not have died when they did if they had not been subject to the behaviours or activities linked to their deaths.
All the risk factors are modifiable through a range of public health and health system interventions.
This is also the first to use methods that allowed a true comparison of a diverse set of risks in terms of how many deaths each of the risk factors is responsible for.
The researchers analysed data from a number of public sources, including from the National Center for Health Statistics and numerous published epidemiological studies and clinical trials.
"The findings should be a reminder that although we have been effective in partially reducing smoking and high blood pressure, we have not yet completed the task and have a great deal more to do on these major preventable factors," said senior author Majid Ezzati.
The study appears in the latest edition of the open-access journal PLoS Medicine.