London, Oct 27 (UNI) Obesity is the main cause of cancer among non-smokers, the World Cancer Research Fund (WCRF) has said.
The WCRF, which spent five years collecting information about the effect bodyweight, diet and physical activity has on the risk of developing cancer, will present its findings to the global conference next week.
The research said smoking is still the single biggest cause of cancers, accounting for one third of the 300,000 cases in the UK alone, each year.
However, only one quarter of people smoke and research found that for non-smokers being overweight or obese was the most important avoidable cause of cancer.
According to Cancer Research UK, 12,000 people a year in the english country could avoid cancer if they maintained a healthy weight.
Obesity is known to cause between nine and 15 per cent of breast cancers -- more than defective genes.
A recent study found women who had gone through the menopause and were obese increased their risk of developing breast cancer by a third.
Obesity is known to increase the risk of cancer by raising the level of hormones such as oestrogen, which feeds many breast cancers.
An obese woman's lifetime risk of developing breast cancer is one in seven compared to one in nine for the general population.
Obesity is also known to increase the risk of bowel cancer, and accounts for between 11 per cent and 14 per cent of cases annually.
Men who are obese have a 60 per cent increased risk of developing the disease.
Studies also estimated that a quarter of kidney cancers, a third of oesophageal cancers and four in 10 womb cancers are caused by obesity.
An epidemiologist at Cancer Research UK Prof Tim Key, who is presenting at the conference here next week, said ''Already the majority of people don't smoke and for them obesity maybe the most important identified cause of cancer.'' He was quoted by the Telegraph as saying that eating a balanced diet was important to remain a healthy weight but there was little credible evidence that so-called superfoods such as garlic, broccoli, or berries actually prevented cancer.
The World Cancer Research Fund's report Food, nutrition, physical activity and the prevention of cancer -- a global perspective will be launched at The Royal Society on November 1.
A panel of 21 experts from around the world have reviewed evidence on what the major causes of cancer and will release details of 10 health recommendations for the prevention of cancer.