Eating 100g per day of red meat over the recommended amount increases bowel cancer risk by 17%, according to a new report.
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LONDON: Red and processed meat increase the risk of bowel cancer, according to the most extensive report yet on the risk factors for the disease, which also pointed to the preventative quality of foods containing fibre.
The report, released as part of World Cancer Research Fund/American Institute for Cancer Research's (WCRF/AICR) Continuous Update Project (CUP), examined the links between bowel cancer risk and diet, physical activity and weight, adding 263 new papers on bowel cancer to the 749 that were analysed as part of a 2007 report.
An independent expert panel then reviewed the results and made judgements.
"On meat, the clear message that comes out of our report is that red and processed meat increase the risk of bowel cancer and that people who want to reduce their risk should consider cutting down the amount they eat," Alan Jackson of the University of Southampton in England and chair of the CUP Expert Panel, said.
Don't eat processed meat, says review
In the new study, findings of 10 new studies on red and processed meat were added to the 14 studies analysed as part of the 2007 report.
The expert panel confirmed that there is convincing evidence that both types of meat increase bowel cancer risk, recommending that people limit their consumption to 500g cooked weight (700 to 750g uncooked weight) of red meat a week - roughly the equivalent of five or six medium portions of roast beef, lamb or pork - and avoid processed meat.
Eating an extra 100g per day of red meat increases bowel cancer risk by 17%, according to the results. Roughly speaking, this would mean that the average person's risk of bowel cancer would increase from five in 100 to six in 100.
Processed meat - including ham, bacon, pastrami and salami, as well as hot dogs and some sausages - is preserved by smoking, curing or salting, or by the addition of preservatives. Hamburgers and minced meats only count as processed meat if they have been preserved with salt or chemical additives. According to the review, eating an extra 100g per day of processed meat increases bowel cancer risk by 36%.
Evidence for fibre benefit "convincing"
The expert panel also concluded that the evidence that foods containing dietary fibre reduce bowel cancer risk has become stronger since the publication of the 2007 report.
They considered the evidence sufficient to strengthen the conclusion that foods containing fibre protect against bowel cancer from "probable" to "convincing".
The analysis for fibre included adding seven more studies to the existing eight from the 2007 report, and the result was that the evidence became much more consistent. This strengthens WCRF/AICR's recommendation for people to consume a plant-based diet including foods containing fibre, such as wholegrains, fruits, vegetables and pulses such as beans.
