20 March 2009
For colorectal cancer, our results are somewhat unexpected. They may be giving a clue that we don't fully understand the relationship of meat with this type of cancer.
Eating a vegetarian diet may reduce your overall risk of cancer, but increase your risk of bowel cancer, new research suggests.
The study, published in the American Journal of Clinical Nutrition, included 52,706 people aged between 20 and 89. Participants were recruited between 1993 and 1999, as part of the European Prospective Investigation into Cancer and Nutrition (EPIC) study, and followed until 2005.
They were separated into four groups: meat eaters, fish eaters, vegetarians and vegans. All cancer diagnoses and deaths were recorded using the National Health Service Central Register.
The overall number of cancer cases was lower in vegetarians and fish eaters than in meat eaters, adding to previous evidence which has shown that vegetarians are less likely to get cancer.
But surprisingly, the number of bowel (colorectal) cancer cases was higher in vegetarians than meat eaters, contradicting previous research. Dr Tim Key, one of the study authors, told Bupa's health information team: "For colorectal cancer, our results are somewhat unexpected.
"Other studies have shown that people who eat a lot of meat may have a higher risk of colorectal cancer than people who eat small amounts of meat. We don't know why our results are different. They may be giving a clue that we don't fully understand the relationship of meat with this type of cancer.
"We are conducting further studies to look into this," Dr Key added.
Heather Caswell, a nutrition scientist from the British Nutrition Foundation, thinks this is an interesting finding.
"When you look more closely at the detail of the study, it can be seen that the meat eaters were actually only eating moderate amounts of meat, which were well within what is recommended for a healthy diet. Further, both groups also had similar intakes of fruit and vegetables, with them both just about meeting the five-a-day target," she said.
"This study highlights the fact that cancer is a complex disease and many different lifestyle factors play a part in determining an individual's risk."
The overall incidence of cancer in the study group was lower than the national average. "This is likely to be down to the fact that all the subjects in this study were fairly healthy - for example they were a healthy weight and the majority were non-smokers," explained Heather Caswell.
"This suggests that an overall healthy diet, which may include moderate amounts of meat, and lifestyle help to reduce cancer risk," she added.
