ABSTRACT

It is well known that diet plays a fundamental role in the etiology of human cancer. Lifestyle choices such as the high consumption of alcohol, dietary fats, and smoking can all contribute to cancer risk. Extensive reviews of epidemiological evidence by Block et al. (1), among others, indicated that dietary intake of fruits and vegetables had a significant impact on several forms of cancers, the mechanisms of which have been described by Steinmetz and Potter (2-4). The general consensus is that increased consumption of fruit and vegetables was associated with a reduced risk of human cancers. Highlighted in these reviews was the strong correlation between a reduction in stomach, esophageal, lung, and colon cancer risk with high consumption of cruciferous vegetables, particularly members of the genus Brassica (1, 5-7). The Brassicaceae comprise a large number of vegetables such as cabbage, cauliflower, brussels sprouts, broccoli, and watercress. One characteristic of cruciferous vegetables is their ability to synthesize phytochemicals known as the glucosinolates (GSLs) (Fig. 1). Upon tissue damage GSLs are hydrolyzed by endogeneous plant myrosinase or alternatively by intestinal bacteria in the gut and converted to bioactive isothiocyanates (ITCs, Fig. 1). ITCs have a wide range of biological functions including antibacterial, antifungal, and anticarcinogenic properties. Furthermore, they are involved in plant herbivore interactions; we recognize them as the characteristic spicy flavors

associated with many of these vegetables, thus giving them their alternative name of mustard oils.