A possible explanation for aspirin's protective effect against bowel cancer is that it is replacing a missing but essential component of the diet. Salicylates used to be a common component of the human diet but have been removed by modern methods of food production, said Professor John Burn (Northern Genetics Service, Newcastle upon Tyne) at the 13th International Congress on Dietetics in Edinburgh on July 25.
Epidemiological studies had shown that aspirin reduced the risk of bowel cancer, he said. Salicylates were produced by plants in response to infection but modern farming methods had effectively removed them from the human diet. An increase in the incidence of bowel cancer seen during the last century could be a result of this removal of salicylates from food, particularly from green vegetables, Professor Burn added.