Researchers have isolated sulforaphane from broccoli, a phytochemical that stimulates the activity of certain tumor-fighting enzymes in the body. Sulforaphane, has been synthesized in the laboratory but it is most effective when ingested naturally in broccoli. Cooking broccoli, whether microwaving or steaming, does not affect the anti-carcinogenic properties of the chemical. Although broccoli was the first vegetable to be studied for its cancer-fighting chemicals, high levels of sulforaphane also turn up in carrots, brussels sprouts, green onions, and cauliflower. In turn, ICZ stimulates the production of enzymes that break down estrogen.
Many experts think most breast cancers result from overexposure to estrogen.
When ICZ was placed in a tissue culture of breast cancer cells, proliferation was inhibited.