Broccoli and cauliflower sprouts contain 10 to 100 times more of a potent anti-cancer agent than mature plants, say researchers at the Johns Hopkins University School of Medicine in Baltimore. Both broccoli and cauliflower belong to the Cruciferae family of the genus Brassica and, along with cabbage and kale, contain substantial amounts of isothiocyanates--powerful inducers of an enzyme system that protects against gene mutation and cancer formation.

This mechanism may explain why people who eat lots of cruciferous vegetables have a reduced cancer risk. Mature vegetables, however, also contain indole glucosinolates that can enhance tumor formation. Glucosinolates smell unpleasant when cooked, and to some people, including at least one former U.S. president, they also taste bad.

Lead researcher Jed Fahey and colleagues found that three-day-old broccoli and cauliflower sprouts contained high levels of an isothiocyanate called "glucoraphanin" and negligible amounts of harmful indole glucosinolates. Even better, extracts from broccoli sprouts proved highly effective in reducing mammary tumor development in rats treated with the carcinogen dimethylbenz(a)anthracene.

Although broccoli sprouts will likely take their place next to alfalfa sprouts in the produce section, mature cruciferous plants still contain abundant vitamins, minerals and fiber not found in sprouts.

--Proc Nat Acad Sci, 94: 10367-72, September 1997