Equol is is made when bacteria in the gut breaks down oestrogen-mimicking chemicals, known as “isoflavones”, chemicals found naturally in soya beans and some other plants. The results of a study published some time ago in Biology of Reproduction indicated that equol effectively blocks a particularly potent form of testosterone, dihydrotestosterone (DHT), linked with both male pattern baldness and an increased risk of prostate cancer.

DHT can be kept in check with Propecia (finasteride), which targets the enzyme that turns testosterone into DHT, and stops hair loss in about 80 per cent of cases and stimulates new growth in 30 per cent. However, benefits are lost when you stop taking the medication, and side-effects can include impotence, Gynocomastia, and possibly impair neurological and cognitive function. Equol, when injected into mice, did not stop DHT from being made per se, but put it in “handcuffs”, stopping it from attaching to the male hormone receptors in the prostate and hair follicles. “Directly binding and inactivating DHT without influencing testosterone gives equol the ability to reduce many harmful effects of androgens without affecting the beneficial ones,” says Professor Robert Handa, an endocrinologist at Colorado State College of Veterinary Medicine, the senior author of the study.

The problem with Equol is that only a subset of the population appear are Equol “producers.”

This study is significant in that it provides evidence that Soy Isoflavones taken in sufficient quantity and duration can turn possibly turn one into an “equol producer.”

There is also evidence that the addition of Sea Vegetables in sufficient quantities to Soy Isoflavones facilitate Equol production even in “non-producers.” More on that in our next update.

In a prior update, we featured a study that showed that consumption of dietary Soy lowered DHT levels, irrespective of one’s ability to produce Equol.

Prostate Cancer Prostatic Dis. 2009 Jul 14.

Isoflavone supplements stimulated the production of serum equol and decreased the serum dihydrotestosterone levels in healthy male volunteers.

Tanaka M, Fujimoto K, Chihara Y, Torimoto K, Yoneda T, Tanaka N, Hirayama A, Miyanaga N, Akaza H, Hirao Y

Department of Urology, Nara Medical University, Kashihara, Japan.

The aim of this study was to evaluate the effect of supplementing healthy men with soy isoflavones on the serum levels of sex hormones implicated in prostate cancer development. A total of 28 Japanese healthy volunteers (18 equol producers and 10 equol non-producers) between 30 and 59 years of age were given soy isoflavones (60 mg daily) supplements for 3 months, and the changes in their sex hormone levels were investigated at the baseline and after administration. The serum and urine concentrations of daidzein, genistein, and the levels of equol in the fasting blood samples and 24-h stored urine samples were also measured. All 28 volunteers completed the 3-month supplementation with isoflavone. No changes in the serum levels of estradiol and total testosterone were detected after 3-month supplementation. The serum levels of sex hormone-binding globulin significantly increased, and the serum levels of free testosterone and dihydrotestosterone (DHT) decreased significantly after 3-month supplementation. Among the 10 equol non-producers, equol became detectable in the serum of two healthy volunteers after 3-month supplementation. This study revealed that short-term administration of soy isoflavones stimulated the production of serum equol and decreased the serum DHT level in Japanese healthy volunteers. These results suggest the possibility of converting equol non-producers to producers by prolonged and consistent soy isoflavones consumption.Prostate Cancer and Prostatic Diseases advance online publication, 14 July 2009; doi:10.1038/pcan.2009.10.