Carrying excess fat around the waist raises the risk of cancer even if the rest of the body is slim, scientists said yesterday. For every extra inch on the waist above a healthy measurement, the risk of bowel cancer goes up 3 per cent, a study by researchers at Imperial College London and the University of Leeds found.
A big waist circumference is a predictor of bowel cancer regardless of overall body mass index (BMI), they concluded. The research, which will be presented at an international cancer conference today, focuses on a review of seven existing papers which found tummy fat is a predictor for bowel cancer. Around 38,500 cases of bowel cancer are diagnosed in Britain each year.
The review provides the strongest evidence so far that the link remains true even if the rest of the body is in proportion and the person is normal weight or only moderately overweight.
As a guide, a healthy waist measurement is defined as less than 31.5in (80cm) for women, less than 37in (94cm) for white and black men and less than 35in (90cm) for Asian men. Experts recommend people keep themselves as slim as they can without becoming underweight.
Professor Martin Wiseman, the medical and scientific adviser for the World Cancer Research Fund (WCRF), which funded the study, said: "This latest study adds to the already strong evidence that carrying excess body fat increases your risk of cancer.
"Scientists now say that, after not smoking, maintaining a healthy weight is the most important thing you can do for cancer prevention. We estimate that more than 2,700 cases of bowel cancer a year in the UK could be prevented through people maintaining a healthy weight.
"But as well as confirming the link between body fat and bowel cancer, this study has strengthened the evidence that where we carry the fat is important. "People who have a large waist should consider losing weight even if they are in the normal BMI range."
Dr Teresa Norat, the lead researcher, said: "This study gives us a better picture of how body fat affects the risk of bowel cancer. Being overweight increases the risk of this type of cancer. People should pay attention to abdominal fatness even if they are in the normal range of weight. More research is needed to understand how abdominal fatness can be prevented in normal and overweight individuals."
The study comes as researchers writing in the European Journal of Cancer said more should be done to prevent people putting on weight, which also increases the risk of bowel cancer.
Dr Esther de Vries from the Erasmus medical centre in Rotterdam and colleagues said that if Europeans put on weight at the same rate as in the US, then by 2019 rates of bowel cancer would rise between 0.7 per cent and 3.8 per cent.
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