Recently scientists in Israel (Nachshon-Kedmi M, Yannai S, Haj A, Fare FA. 2003, Food and Chemical Toxicology , 41, 745-752) have reported that cultured human prostate cancer cells are killed by specific compounds found in juices of cruciferous vegetables such as cabbage, broccoli, and Brussels sprouts. Testing both indole-3-carbinol (I3C) and 3-,3'-diindolyl methane (DIM), the two most readily available dietary indoles, these scientists showed that these compounds directly kill the cancer cells without harming normal cells. Prostate cancer and BPH is rare in nations or cultures where eating many servings of cruciferous vegetables each week is the custom. Hence, people who have such diets or who take dietary indoles as supplements have built-in protection that may avert cancers that they never materialize. Killing a cancer cell when there is only one of them is a big advantage. However, there is an additional mechanism of prostate protection is available from dietary indoles.

Over the past 40 years I3C has been shown to be effective in a variety of roles in cancer prevention and cancer treatments. This compound, I3C, is relatively unstable in stomach acids where it is transformed to a number of related compounds, including DIM. Recent studies have shown that DIM is more effective on a weight basis than I3C and that many of the benefits previously ascribed to I3C may be due to DIM and related compounds. There are also some additional values of plant nutrients in the cruciferous vegetables.

It has been shown that some beneficial results from I3C and DIM come from their ability to modify the metabolism of sterol sex hormones, making them less likely to trigger unwanted growth, both benign and malignant. Modification of hormone metabolism can be monitored by a test for different hydroxyestrones in the urine of both men and women. Many studies have shown that the dietary indoles will induce the metabolism of estradiol to 2-hydoxyestrone in preference over 16a-hydroxyestrone. The 16a-hydroxyestrone is known to accelerate breast cancer and many other tumor growth conditions, while the 2-hydroxyestrone is known to inhibit such growth. A recent study by Muti and coworkers (Multi P, et al., 2002, Cancer Causes and Control, 13, 947-955) has definitely shown that 16a-hydroxyestrone has an accelerating effect in the growth of prostate cancer. This finding shows that there are two mechanisms by which the dietary indoles contribute to prostate health.

This means that whatever the hormone balance might be for a given man, the hormonal causes and tendencies toward BPH and subsequent cancer are minimized by the inclusion of DIM. For these reasons a person selecting a nutritional supplement should seek a product that contains large amounts of DIM.


G. Merrill Andrus, PhD 2003

It is note worthy that American Caucasian and Japanese men living an American lifestyle have 10 times the average "incidence rate" of serious prostate problems compared to Japanese men living in Japan (Nomura 2000). The differences in diet could account for the dramatic comparison! Japanese men consume a much greater volume of plants from the Brassica or Cruseferous vegetables on a daily basis than Americans, who frequently shy away from vegetables like Brussels sprouts due to their pungent odor and bitter taste (Kristal 2002).

"There are excellent human studies on indole-3-carbinol or I3C , for its anticancer effects and lowering of serum estrogen levels. These have been published in Cancer Research, Journal of the National Cancer Association, Anticancer Research, Annals of the NY Academy of Sciences and other major journals. I3C is found in cruciferous vegetables (cabbage, broccoli, Brussels sprouts and cauliflower). You can take 400 mg a day or use the metabolic derivative di-indolyl methane , or DIM , 200 mg a day. I feel the studies on I3C apply equally to DIM and the latter is a much better bargain and twice as powerful. High estrogen levels in our bodies cause many problems as we age, and this is an excellent way to reduce them and improve estrogen metabolism."

Roger Mason, The Natural Prostate Cure , Safe Goods Publishing, p. 23.

Prostate Cancer News:
Broccoli, Cauliflower May Help Fight Prostate Cancer

A chemical produced when digesting such greens as broccoli and cauliflower can stifle the growth of human prostate cancer cells, according to researchers at the University of California - Berkeley.

The researchers said that 3,3'-diindolylmethane (DIM), which is obtained by eating cruciferous vegetables in the Brassica genus, acts as a powerful anti-androgen that inhibits the proliferation of human prostate cancer cells in culture tests.

Androgens are important male hormones, but the androgen dihydrotestosterone (DHT) can stimulate the expression of prostate specific antigen (PSA), which acts as a growth factor for prostate cancer.

In their study, the researchers found that DIM inhibits the actions of dihydrotestosterone (DHT). Androgen-dependent cancer cells treated with a solution of DIM grew 70 percent less than the same type of cancer cells left untreated and researchers found a drop in the level of PSA.

"As far as we know, this is the first plant-derived chemical discovered that acts as an anti-androgen," said Leonard Bjeldanes, chair of nutritional sciences and toxicology. "This is of considerable interest in the development of therapeutics and preventive agents for prostate cancer."

Vegetables such as broccoli, Brussels sprouts, kale and cauliflower are rich sources of indole-3-carbinol (I3C), which the body converts into DIM during digestion.

From Senior Health Week: Prostate Cancer , October 8, 2003

3,3' - Diindolylmethane Functions as a Potent Antiandrogen in LNCaP Human Prostrate Cancer Cells

By: Hien Le

3,3¹-Diindolylmethane (DIM), is a major digestive derivative of indole-3-carbinol (I3C), a potential anticancer component of dietary cruciferous vegetables. Our results indicate that DIM has antiproliferative effects and is a potent antiandrogen in cultured prostate LNCaP cells, an androgen dependent human cancer cell line. DIM depresses cell proliferation by inducing a G1 cell cycle arrest of LNCaP cells and inhibiting dihydrotestosterone (DHT) stimulation of DNA synthesis. Furthermore, the effects of DIM on the promoter activities of the Mouse Mammary Tumor Virus single LTR, which contains a single ARE region, and a PSA promoter-enhancer containing three ARE, were examined. A concentration-dependent inhibition of DHT induction by DIM was observed when these promoters were transiently transfected into LNCaP cells followed by luciferase analysis. A similar effect of DIM was not observed in androgen independent PC-3 cells until a wild type androgen receptor was co expressed with the reporter plasmid. Our data strongly support the hypothesis that the androgen receptor (AR) is a major target of DIM regulation in prostate cancer cell growth. Competitive binding assays were performed indicating that DIM competes with the natural ligand for AR binding. Thus, DIM is a potent antiandrogen and acts as a classical antiandrogen in vitro. DIM can potentially control the emergence and proliferation of prostate cancer cells by regulating androgen receptor dependent gene transcriptional activation in prostate cancer epithelial cells. We have uncovered a new mode of action for DIM, in which it functions to block androgen mediated signal transduction by directly inactivating the AR.
(Hien Le, University of California at Berkley) nutrition.berkeley.edu