How red meat can damage DNA

Scientists may have finally worked out why too much red meat appears to cause bowel cancer.

The disease is one of the UK's biggest killers. Over 16,000 people die from bowel — sometimes called colon or colorectal — cancer every year.

The new research does not mean we should all stop eating beef and other red meat but that we shouldn't eat too much of it and that it needs to be part of a balanced diet with plenty of fibre.

It appears that there are compounds in red meat which can affect the DNA and lead to cancer. 'It is the first definite link between red meat and the very first stage in cancer,' Professor Sheila Bingham, of the Medical Research Council Dunn Nutrition Unit in Cambridge told Reuters.

Bingham and her team had already shown in earlier research that there was a strong relationship between eating red and processed meat and the risk of colon cancer.

The risk of colorectal cancer was 33% higher in people who regularly ate more than two portions of red or processed meat a day compared to someone who ate less than one portion a week.

In their latest study, published in the journal Cancer Research, the scientists studied cells from the lining of the colon from people who consumed red meat, vegetarian, high red meat or high fibre diets for 15 days.

They found that red meat consumption was linked to increased levels of substances called N-nitrosocompounds, which stuck to DNA, making it more likely to undergo changes that increased the chance of cancer.

The DNA damage may be repaired naturally in the body, and fibre in the diet may help the process. But if it isn't, cancer can develop, Bingham said.

The scientists said the findings could help to develop a screening test for very early changes related to the disease.

Probably 70% of colorectal cancers can be prevented by changes in diet and nutrition.

Risk factors are:

• lack of exercise and
• diets rich in fat, animal protein and refined carbohydrates (Refined carbohydrates are processed versions such as white bread, white pasta and white sugar rather than unrefined brown versions.)

Look out for:

• diarrhoea
• constipation and
• bleeding from the bottom.

These can all be symptoms of colon cancer.

Last summer, the NHS announced that bowel cancer screening would begin in April this year for men and women aged 60-69.

• This month's feature: Ten tips from a cancer expert who says 4 out of 5 coancers can be avoided by simple lifestyle changes.