A team of researcher has found that a diet high in fat increases the risk of bowel cancer as it causes cells in the gut to mutate. The study on laboratory mice fed on fatty food found that they were more likely than normally-fed mice to suffer changes to the cells of the gut lining that can lead to the formation of cancerous tumours.
The findings could help to explain the changes to the body’s cells that account for the established link between fatty food and the higher-than-average rate of certain types of cancer in overweight people, the researchers said.
Lead author Semir Beyaz noted that the epidemiological link between a high-fat diet and colorectal cancer has been reported for many years, but the underlying mechanisms were not known, adding that their study for the first time showed the precise mechanisms of how a high-fat diet regulates intestinal stem-cell function and how this regulation contributes to tumour formation.
The mice in the study were fed an exceptionally fatty diet, containing 60 per cent fat, for between 9 and 12 months – compared to a typical western diet of 20 to 40 per cent fat. The mice became up to 50 per cent heavier than normally-fed mice and developed more intestinal tumours, the study found.
The researchers found that the high-fat intake significantly increased the overall pool of intestinal stem cells, the “mother” cells that develop into the specialised tissue of the gut, as well as increasing the number of other cells that started to behave like stem cells.
It is these stem cells, and stem-like cells, that can begin to divide uncontrollably to become cancerous tumours, which appears to explain why high-fat diets increase the risk of colorectal cancers, the scientists said.
The study is published in journal Nature.