Salicylic acid: a link between aspirin, diet and the prevention of colorectal cancer

Aspirin was introduced into clinical practice more than 100 years ago. This unique drug belongs to a family of compounds called the salicylates, the s implest of which is salicylic acid, the principal metabolite of aspirin. Sa licylic acid is responsible for the anti-inflammatory action of aspirin, an d may cause the reduced risk of colorectal cancer observed in those who tak e aspirin. Yet salicylic acid and other salicylates occur naturally in frui ts and plants, while diets rich in these are believed to reduce the risk of colorectal cancer. Serum salicylic acid concentrations are greater in vege tarians than non-vegetarians, and there is overlap between concentrations i n vegetarians and those taking low-dose aspirin. We propose that the cancer -preventive action of aspirin is due to its principal metabolite, salicylic acid, and that dietary salicylates can have the same effect. It is also po ssible that natural salicylates contribute to the other recognized benefits of a healthy diet.