Diindolylmethane: The Better Choice For Estrogen Metabolism
The following are highlights from "Safer Estrogen with Phytonutrition", by Michael A. Zeligs, M.D.
Allergy Research Group
Cruciferous vegetables, such as cabbage, cauliflower, and broccoli, possess unique phytonutrient con-stituents able to improve the metabolism of estrogen. The most active of these phytonutrients with regard to estro-gen is the dietary indole, diindolylmethane. Supplemental use of diindolylmethane provides the basis for nutritional support to enhance the beneficial action and safety of estrogen. An optimal "estrogen balance" has implications for cancer pre-vention and successful aging in both women and men.
Dietary Ingredients Improve Estrogen Metabolism
H. Leon Bradlow, Ph.D. and his group at the Strang Cancer Prevention Laboratory in New York were the first to establish the link between phytonutrients from cruciferous vegetables and estrogen metabolism. They showed that supplemental use of a single cruciferous phytochemical can act to promote a dramatic and beneficial change in the metabolism of estrogen. This change in metabolism has the power to greatly reduce estrogen exposure as a risk for cancer.
This discovery demonstrated that the metabolism and growth promoting activity of estrogen is modified by the intake of mil-ligram amounts of dietary indoles from crucifers. When these cruciferous phytochemicals are added to the diet, estrogen action is regulated and its metabolism is shifted. This produces a predominance of 2-hydroxy and 2-methoxyestro-gens. These active metabolites have been called "good estrogens", function as antioxidants, and have the power to eliminate damaged or cancerous cells throughout the body. Without these phytochemicals in the diet, there is increased production of a different, undesirable group of estrogen metabolites. These so-called "bad estrogens", act negatively to allow oxidation, to damage DNA, and to promote cancer.
Supplemental use of diindolylmethane, the most active crucif-erous indole, can restore and maintain a favorable balance of estrogen metabolites and provides an innovative approach to reducing the estrogen-related risk of breast cancer. Therefore, diindolylmethane supplementation can increase the safety of estrogen replacement therapy in post menopausal women. In addition, aging-related alteration in estrogen metabolism is an under appreciated factor in men's health.
Diindolylmethane use by men promotes the same beneficial estrogen metabo-lism as seen in women. Improving estrogen balance in men may serve as a basis for enhancing prostate health.
Diindolylmethane & Estrogen Balance
Diindolylmethane is the most active cruciferous substance for promoting beneficial, estrogen metabolism in women and men. Diindolylmethane is found in cruciferous vegetables including broccoli, cauliflower, cabbage and Brussels sprouts. Diindolylmethane is formed from its precursor indole, Indole-3- carbinol (I3C), after the enzymatic release of I3C from parent glucosinolates found in all cruciferous vegetables. The supplemental use of diindolylmethane began with early experiments which demonstrated that animal diets with added diin-dolylmethane, like diets with added cruciferous vegetables, prevented chemically induced cancer. Pure diindolylmethane was first used in 1987 as a dietary supplement in animals, shown to be non-toxic, and to prevent breast cancer caused by the carcinogen, dimethybenz[a]anthracene. Similarly, the initiation pathway to chemically induced colon cancer was inhibited with the diindolylmethane precursor, I3C. The mechanisms by which diindolylmethane prevents cancer in animals has subsequently been shown to involve a reduction in activity of the estrogen receptor system, promotion of beneficial estrogen metabolism, and support for selective apoptosis, or "programmed cell death" wh