Cancers of the gut are one of the major causes of death from cancer, but a review published this week shows that they are also amongst the most preventable through changes in diet.
Of the 10 million new cases of cancer diagnosed in 2000, around 2.3 million were cancers of the digestive organs – pharynx, oesophagus, stomach or colorectum. Studies have shown that they are not purely genetic and can be modified by diet.
Professor Ian Johnson, author of the review and head of Gastrointestinal Health and Function at the Institute of Food Research, said: “The adverse effects of diet are caused by over-consumption of energy coupled with inadequate intakes of protective substances, such as micronutrients, dietary fibre and a variety of plant chemicals”.
The walls of the gut are lined with a layer of cells, the epithelium, covered with a film of mucus. The epithelium is the first contact for food, bacteria and anything else ingested. It is the body’s first line of internal defence, but can also be susceptible to the development of abnormalities over time. The epithelium is normally renewed by rapidly dividing stem cells, which can also give rise to new growths called polyps. These usually remain benign, but some may acquire so many genetic abnormalities that they eventually form a cancerous tumour.