vitamin-like antioxidants that help prevent damage to deoxyribonucleic acid (DNA). These substances are found in certain fruits and vegetables, such as tomatoes, pink grapefruit, and watermelon. Some studies have suggested they might help lower the risk of some cancers (especially prostate cancer), but other studies have not found a link between lycopene and cancer risk. Research in this area continues. See also antioxidants, deoxyribonucleic acid.