According to a new report in the American Chemical Society’s Journal of Medicinal Chemistry, scientists have discovered how broccoli, cauliflower, watercress and other cruciferous vegetables help stunt cancer growth. The vegetables contain substances called isothiocyanates (ITCs) that appear to target and block a defective p53 gene associated with cancer. Healthy p53 genes act as tumor suppressors and prevent cells from starting the abnormal growth that is a hallmark of cancer. The mutated genes—which occur in half of all human cancers—do not offer that protection. ITCs appear to work by removing defective p53 genes while preserving normal, protective ones. Researchers believe the substances support the advice of moms through- out the ages: Eat your vegetables.