The report, published in tomorrow's issue of The Lancet (vol 366, no 9499), estimates that 2.43 million, or 35 per cent of the 7 million deaths from cancer in 2001 were caused by a lifestyle that could have been changed.
The Harvard University researchers based their findings on a comprehensive review of scientific studies and other sources such as government reports. They also re-analysed some of the original data from the studies.
Smoking, alcohol use, and low fruit and vegetable intake were the leading risk factors for death from cancer worldwide and in low-and-middle-income countries.
In high-income countries, smoking, alcohol use, and overweight and obesity were the most important causes of cancer.
The charity Cancer Research UK estimates that around half of all cancers in the UK could be prevented by changes to lifestyle.
