Cruciferous vegetables -- broccoli, cabbage, leafy greens, cauliflower -- help prevent breast and prostate cancer, U.S. researchers say. Researchers at Vanderbilt University\'s Ingram Center showed a diet rich in cruciferous vegetables -- specifically the indoles they contain -- protects and improves breast cellular health. \"Indoles are organic compounds that have a positive impact on cellular health. One in particular, diindolylmethane has been shown to support the immune system and help keep hormones in balance, particularly estrogen,\" the researchers said. \"In the body, estrogen gets broken down into a variety of metabolites, some of which promote healthy cells. Unfortunately, others can cause problems. Diindolylmethane has been shown to help the body produce beneficial estrogen metabolites with anti-oxidative effects.\" Certain estrogen metabolites, which have been associated with obesity, chemical exposure and other causes, have been shown to derail cellular healthy, but diindolylmethane has proven to increase the good kind of hormone metabolites and decrease the kind that can challenge health, the study said. Breast, prostate and other areas of hormone-related cellular health depend on this delicate balance, the study said.