Issues

Watercress (Nasturtium officinale), a vegetable commonly used in salads or as a garnish and readily available in most grocery markets, is a member of the family of cruciferous vegetables known for their content of glucosinolates. These unique plant defense compounds are converted during chewing or cutting to sharp tasting isothiocyanates in a reaction catalyzed by the plant enzyme myrosinase. Many of the released isothiocyanates have potential cancer prevention properties. Thus, consumption of normal salad size portions of watercress releases milligram amounts of 2-phenethyl isothiocyanate (PEITC), shown in many studies to prevent cancer in laboratory animals treated with carcinogens and to induce detoxifying enzymes such as glutathione S-transferases. In the study starting on page 143, Bonorden and colleagues describe a collaboration between the food industry and scientists in academia to prepare approximately 100 lbs of freeze-dried watercress. This watercress will be incorporated into a beverage to be used in a clinical trial which will determine its ability to induce the detoxification of commonly occurring environmental carcinogens such as benzene, 1,3-butadiene, and acrolein. This food based approach to cancer prevention has many practical advantages compared to the use of pure drug substances but has not yet been widely tested and validated in trials such as the one described here.