The study conducted by researchers at the Medical Research Council (MRC) Dunn human nutrition unit in Cambridge says that a comparison of cells from the lining of the colon shows that people who eat a diet high in red meat have a significant increase in levels of DNA damage compared with vegetarians.
The findings follow a major European study last year which indicated that people who eat two portions of red or processed meat weekly increase their risk of bowel cancer by 35 per cent compared with those who eat one portion. The research, part funded by the MRC, monitored the diets of nearly half a million men and women in 10 countries over five years.
The new study, led by Sheila Bingham and published in the journal Cancer Research monitored 21 volunteers who each undertook three 15 -day diets. The researchers found that when the red meat diet was compared with the vegetarian diet, there was a consistent and significant increase in DNA damage while damage was intermediate with the red meat/high fibre diet.
But the Meat and Livestock Commission pointed out that the research assessed people eating 420g (15oz) of red meat a day - over five times more than the average man's quota of 80g (3oz), and over eight times the average woman's intake of 50g.
Guy Attenborough, the Commission's spokesman said: "The results don't in themselves prove a link between colorectal cancer and meat consumption. The study is a small scale study which is tentatively suggesting a mechanism by which red and processed meat might increase an individual's risk of developing colorectal cancer. The authors themselves acknowledge that larger-scale prospective studies are needed to identify how important and robust this suggested mechanism is."
He added that experts agreed that colorectal cancer is influenced by many factors. "Smoking and obesity head the list with alcohol, lack of exercise, diet and age."