Preparation of a Beverage Containing Freeze-Dried Watercress for a Clinical Trial of Carcinogen and Toxicant Detoxification.

Watercress is an excellent source of phenethyl isothiocyanate (PEITC), shown in many studies to enhance carcinogen and toxicant detoxification and to inhibit carcinogenesis. Based on a previous observation that PEITC can enhance the detoxification of common environmental pollutants such as acrolein, crotonaldehyde, benzene, and 1,3-butadiene, we designed a clinical trial testing the hypothesis that daily consumption of a drink containing freeze-dried watercress, an abundant source of PEITC, would have a similar effect, particularly observed in subjects who were null in certain glutathione S-transferase genes. This manuscript describes the preparation of nearly 100 pounds of freeze-dried watercress for this trial, starting with laboratory-scale pilot studies and proceeding to industrial-scale production of the fully validated product in compliance with all food safety requirements. Initial results validating subject compliance in the clinical trial are also presented. PREVENTION RELEVANCE: This study describes the preparation of a beverage containing freeze-dried watercress suitable for consumption in a clinical trial to determine whether a constituent of this beverage-PEITC, which has cancer prevention properties-can enhance detoxification of common environmental carcinogens and toxicants such as benzene, which may have a role in environmentally induced cancer. See related Spotlight, p. 139.