Cambridge: Eating red met does raise the risk of bowel cancer, scientists at the MRC Dunn Human Nutrition Unit in Cambridge.

Earlier research, byt he UK’s Medical Research Council, has already shown that eating more than n 5 1/2oz a day – the equivalent of a burger and two sausages – increases chances of getting the disease by a third.

But the new research claims to show the cause: a substance produced in the gut by the meat damaged DNA, making the cells more likely to mutate and become cancerous.

Experts have previously said that diet, smoking, inactivity and obesity can all raise the risk.

The Cambridge team looked at the diets and cancer risk of nearly 500,000 men and women from across Europe. They discovered the cancer risk increased the more red meat consumed.

In the latest study published in the Journal of Cancer Research, the scientists examined the cells of the lining of the colon in healthy people on diffierent diets and looked at how their diet affected the cell DNA.

They found that when a red meat diet was compared with a vegetarian diet, levels of DNA damage increased. The culprit appeared to be substances called N-nitrosocompounds, which are formed in the large bowel after eating red meat.

Some of the compounds are thought to combine with DNA and destabilise it, making it more likely to undergo the harmful changes or mutations that can lead to cancer.