Healthier living could prevent about a third of the most common cancers in rich countries and about a quarter in poorer ones, suggests a major international study.
Better diets, more exercise and controlling weight could also prevent more than 40% of colon and breast cancer cases in some countries, according to the study from the World Cancer Research Fund and the American Institute for Cancer Research.
"At the time of publication, roughly 11 million people worldwide are diagnosed with cancer and nearly eight million people die from cancer each year," said Michael Marmot, who led the study. "However, cancer is mostly preventable."
The study involved 23 experts who analysed both the incidence of 12 common cancers across the world and data on diet, exercise and weight to see how these factors contributed to kidney, mouth, lung, gallbladder and other cancers.
The researchers found that healthier living would prevent 43% of colon cancer cases and 42% of breast cancer cases in Britain, and 45% of bowel cancer and 38% of breast cancer cases in the United States.
The study recommended - in line with what health experts, including governments and the UN World Health Organization, have long been advising - that people follow diets based on fruits, vegetables and whole grains and go easy on red meats, dairy products and fats.
The panel of world experts included Professor Jim Mann of Otago University, who says the recommendations are particularly relevant in New Zealand at a time when the Government is making decisions about policies relating to public health.
New Zealand's Cancer Society welcomed the comprehensive report, saying though a number of its recommendations are already being carried out, more can be done.