3.27.07 Cabbage & Estradiol For Men With Prostate Cancer Diagnosis

I have just encountered a very good example of the interactions between food and drugs used to treat prostate cancer that I’d like to share with you. My goal is to alert you about (1) indole-3-carbinol and estradiol interactions, and (2) warn those of you on estradiol about taking in large amounts of cabbage or related veggies.

Multiple studies have shown that eating vegetables related to the cabbage family (brassica) reduce the risk of a range of cancers. This has led to rather extensive research into the various plant chemicals involved in this anticancer effect. One compound that has emerged is indole-3-carbinol. This compound has a number of interesting actions. For example, it blocks bcl2, a protein that appears to help prostate cancer cells to survive hormonal therapy. It also stimulates the liver enzymes involved in the metabolism of estradiol, the most powerful form of estrogen. Indole-3-carbinol treatment results in estradiol being converted into estrone and other less active estrogenic compounds. This has been invoked as a possible means to lessen the risk of estradiol-stimulated cancers, such as carcinomas of the breast and endometrium (lining of the uterus).

There is also a literature linking exposure to elevated estradiol levels and the development of prostate cancer. Because of this and the link to hormone resistance through bcl2, there is a growing trend for men with prostate cancer to take indole-3-carbinol.

While estradiol may be an actor in the development of prostate cancer, it is also true that it is well established as a form of hormonal treatment of this disease and has been since the 1950s. With the recent literature on the use of transdermal estradiol in the treatment of prostate cancer, I have made this a major part of my second line hormonal therapy program. Recently, I was able to observe a very interesting interaction between indole-3-carbinol and transdermal estradiol.

Patient D has prostate cancer now resistant to treatment with Lupron and Casodex. We were attempting to treat his disease with transdermal estradiol and found that it was difficult to reach serum estradiol levels. After some discussion, the patient pointed out that over time he had changed his dose of indole-3-carbinol. When we reviewed the results, we found that his serum estradiol levels were being suppressed dramatically at the higher doses of indole-3-carbinol.If you are on transferal transferal or transferal forms of estradiol, avoid the following foods: cabbage, broccoli, rabini, wasabi, radish, arugula, kale, turnip, mustard and mustard greens, collard greens, and brussels sprouts.

This finding illustrates several points. First, indole-3-carbinol is, indeed, powerful enough that it can reduce serum estradiol levels. Second, this is not a good thing if your goal is to treat cancer by dramatically increasing serum estradiol levels. Third, it is often said about supplements that they might help and certainly will not hurt. This is not necessarily the case. Supplements can contain very powerful chemicals with the potential to help or hurt you, depending on the situation.

The rest of this article can be read in volume 9:11 of Prostate Forum. Click here to download this issue now.