According to the World Health Organisation, dietary factors account for 30% of all cancers in the Western world. These factors are the next prevalent cause behind tobacco. We know that diets high in fruit and vegetables may have a protective effect by reducing the risk.

Watercress has an abundant supply of substances known as glucosinolates. When you chew watercress it is broken down by the enzyme myrosinase into isothiocyanates. It is these substances that research has shown to have anticancer effects. Isothiocyanates can be found in other vegetables such as brocolli. brussel sprouts, kale, cabbage and turnip but watercress is the richest source of these anti-cancer substances. It seems that not only do they prevent cancer they have been found to kill cancer cells.

The answer is eat watercress as part of a healthy diet.