The study by French health authority Santé publique France said that four out of ten cancer cases could be avoided by a change in behaviour.
And in France that means less smoking and drinking alcohol, which were the top two causes of “preventable” cases of cancer in France, followed by poor diet and obesity, according to figures released by the health authority on Monday.
Each of these factors kill a lot more people than they should, according to the International Agency for Research on Cancer (IARC) and Santé publique France.
Of the 346,000 cases of cancer diagnosed in 2015 among those aged 30 and over, “142,000 (41 percent) could have been avoided if the entire population had not been exposed to the risk factors studied, or if exposure had been limited,” said the IARC.
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Cancer is the leading cause of death in France, ahead of cardiovascular diseases, with tumors killing 164,000 people in 2013, according to France's Ministry of Health.
Smoking-related cancers such as lung cancer, among others, mainly affect the working classes.
The risk of getting these cancers is 1.5 to 2 times higher among the 20 percent most disadvantaged people in France compared to the 20 percent at the other end of the spectrum, said the IARC.
“Too few French people are aware of the risks they are taking,” said Health Minister Agnès Buzyn, who has taken a strong stance against smoking in France, in March.
Alcohol is responsible for 8 percent of new “preventable” cancer cases, with the authors of the study saying that France could do much more to prevent alcoholism and advocating “increasing prices and taxes” on alcohol.
Meanwhile, poor diet and obesity are each responsible for 5.4 percent of new “preventable” cancer cases, with the IARC pointing to the risks of a “low consumption of fruits, vegetables, dietary fiber and dairy products combined with a high consumption of red meats and processed meats”.