Cooking vegetables is usually a good idea: Heat breaks down cell walls, releasing antioxidants. But heating cruciferous vegetables (part of the Brassicae family) actually destroys their unique anti-carcinogenic potential. That’s because crucifers, unlike other types of vegetables, are high in glucosinolate, a plant compound that produces naturally occurring small molecules called isothiocyanates, which have been shown to fight cancer. “An …