Daidzein supplement information, health benefit, anti cancer effect - does it influence DHT levels?
Conversion into equol and review of published clinical trials
July 8 2016 by
Ray Sahelian, M.D.

Daidzein is an isoflavone found in abundance in soy. Isoflavones are types of flavonoids found in plants which have various health benefits. The main sources for isoflavones are soy products, beans, peas, nuts, grain products, coffee, tea and certain herbs such as red clover. Genistein is one of the best known and studied isoflavones. Other isoflavones include aglycon, glucoconjugate and equol. A plant in the news lately that contains daidzein is Kudzu which has been found to have beneficial effects in those who drink alcohol more than they should. There is also a prostate formula with daidzein, for more information regarding this formula see Prostate Power Rx.

Daidzein has been shown in laboratory studies to have several beneficial properties:
     Anti-tumor activity, including prostate, colon, pancreas, cervix, and breast.
     Weak pro-estrogen and anti-estrogen activity which may be helpful in postmenopausal women.
     It is metabolized in the colon by bacteria to equol, another isoflavone.

Purchase Daidzein and Genistein pills, Isoflavones, 1000 mg each pill
Source Naturals

Studies have shown that genistein and daidzein can bind to the same receptor sites as estrogen. Soybeans are significant dietary source of isoflavones; however, the amount of soy foods necessary to meet the body's needs can be difficult to incorporate into today's diet. In Asia, where soy is a staple, the daily intake of isoflavones can be up to 20 times that of a Western diet. Source Naturals Genistein and Daidzein are made from isoflavone-rich soybean powder that yields a consistent standardized isoflavone content. This unique chemical-free process requires approximately 400 pounds of soybeans to yield just one pound of finished product.

Dosage: One pill a few times a week.

Purchase Daidzein Genistein, or Prostate Power Rx
Supplement Facts: Serving Size 2 Tablets
Amount Per Serving:
Calories 10
Sodium 5 mg
Total Carbohydrates 1 g
Protein 1 g
Isoflavone Rich powder  2 grams
Soybean Powder (Soylife) Yielding:
   Daidzein 34 mg
   Glycitein 20 mg
   Genistein 8 mg
   Total Isoflavones 62 mg

Suggested Use: One daidzein - genistein tablet a few times a week, or as recommended by your health care professional.

Prostate Power Rx

With saw palmetto, pygeum, stinging nettle, quercetin, daidzen extract and several key Ingredients for support of optimal prostate health.
This formula has been designed to support:

  Normal prostate size
  Cellular support against oxidants in the prostate

Saw Palmetto extract (standardized to contain 45% fatty acids - serenoa repens fruit)
Stinging Nettle 4:1 extract (urtica diocia root)
Quercetin flavonoid
Rosemary 4:1 extract (Rosemarinus officinales leaf)
Beta Sitosterol
Pygeum 4:1 bark extract (Pygeum Africanum)
Daidzein (standardized to contain 40% isoflavones)
Genistein (standardized to contain 40% isoflavones)
Lycopene (Lycoperscion escatatum fruit)

Future research is likely to uncover various benefits of this substance.

Breast cancer
Daidzein induces MCF-7 breast cancer cell apoptosis via the mitochondrial pathway.
Ann Oncol. 2010
We demonstrated that daidzein-induced apoptosis in MCF-7 cells was initiated by the generation of reactive oxygen species (ROS). Furthermore, we showed that this was accompanied by disruption of mitochondrial transmembrane potential, down-regulation of bcl-2, and up-regulation of bax, which led to the release of cytochrome C from the mitochondria into the cytosol, which, in turn, resulted in the activation of caspase-9 and caspase-7, and ultimately in cell death. Daidzein could induce breast cancer cell apoptosis through the mitochondrial caspase-dependent cell death pathway.

The soy isoflavone daidzein improves the capacity of tamoxifen to prevent mammary tumours.
Eur J Cancer. 2005.
This study conclusively shows for the first time the combination of daidzein with tamoxifen produces increased protection against mammary carcinogenesis, while the combination of genistein with tamoxifen produces an opposing effect when compared with tamoxifen alone.

Hair growth?
Does daidzein help with hair growth?
   Theoretically it may since it converts into equol but what actually happens when ingested by humans for prolonged periods is difficult to predict.

Immune system
J Surg Res. 2015. Daidzein pretreatment improves survival in mouse model of sepsis. Daidzein pretreatment for 7 d in sepsis increased the survival time in mice, which may be relate to decrease in bacterial load, anti-inflammatory effect, and protection from lung injury.

Lipid, Triglyceride, Cholesterol level, heart disease
J Nutrition. 2014. Daidzein supplementation decreases serum triglyceride and uric acid concentrations in hypercholesterolemic adults with the effect on triglycerides. This major isoflavone can be metabolized to equol in certain individuals. The effects of isoflavones alone and equol status on lipid profiles are still controversial. To evaluate the 6-mo effects of daidzein on cardiovascular risk factors in hypercholesterolemic individuals and the interactions of these effects with equol status and estrogen receptor (ESR) genotypes, we conducted a randomized, double-blind, placebo-controlled trial consisting of 210 hypercholesterolemic adults (40-65 y old). The participants were randomly assigned (177 completed) to consume placebo, 40 mg daidzein (DAI40), or 80 mg daidzein (DAI80) daily for 6 mo.

PLoS One. 2014. Cardiovascular Risks in Relation to Daidzein Metabolizing Phenotypes among Chinese Postmenopausal Women. Equol / O-DMA producers had more favorable cardiovascular risk profiles than non-producers in prehypertensive postmenopausal women.

Genistein, daidzein, and coumestrol inhibit aromatase, 3beta-hydroxysteroid dehydrogenase and 17beta-hydroxysteroid dehydrogenase (17beta-HSD). A newly isolated rod-shaped, gram-negative anaerobic bacterium from human feces, named Julong 732, was found to be capable of metabolizing the isoflavone dihydrodaidzein to S-equol under anaerobic conditions.
Inulin in the diet or taken as a supplement increases the plasma concentrations of the soybean isoflavones daidzein and genistein. It appears that the absorption of genistein and daidzein is facilitated by inulin.

Side effects, safety, risk, danger
No major adverse effects have been mentioned in the medical literature.

Daidzein research studies
Gut bacterial metabolism of the soy isoflavone daidzein: exploring the relevance to human health.
Exp Biol Med. 2005. Fred Hutchinson Cancer Research Center, Seattle, WA
The indigenous intestinal microflora are involved in a variety of processes within the human body, and are important for maintaining host health. As such, interindividual differences in the ability to harbor certain intestinal bacteria might be associated with interindividual differences in health and/or disease susceptibility. Daidzein, an isoflavone phytoestrogen found in soy, is metabolized to equol and O-desmethylangolensin (O-DMA) by intestinal bacteria. The specific bacterium/bacteria responsible for equol and O-DMA production in humans have yet to be identified definitively, but in vitro and animal studies have suggested that equol and O-DMA are more biologically active than their precursor daidzein. Interestingly, substantial interindividual differences in daidzein metabolism exist; following soy or daidzein consumption, approximately 30%-50% of the human population produce equol, and approximately 80% to 90% produce O-DMA. Observational and intervention studies in humans have suggested that the ability to produce equol and O-DMA may be associated with reduced risk of certain diseases including breast and prostate cancers.

Soy isoflavone phyto-pharmaceuticals in interleukin-6 affections; Multi-purpose nutraceuticals at the crossroad of hormone replacement, anti-cancer and anti-inflammatory therapy.
Biochem Pharmacol. 2004.
Interleukin-6 is a cytokine which plays a crucial role in immune physiology and is tightly controlled by hormonal feedback mechanisms. After menopause or andropause, loss of the normally inhibiting sex steroids (estrogen, testosterone) results in elevated IL6 levels that are further progressively increasing with age. Interestingly, excessive IL6 production promotes tumorigenesis (breast, prostate, lung, colon, ovarian), and accounts for several disease-associated pathologies and changes of advanced age, such as osteoporosis, rheumatoid arthritis, multiple myeloma, neurodegenerative diseases and frailty. In this respect, pharmacological modulation of IL6 gene expression levels may have therapeutic benefit in preventing cancer progression, ageing discomforts and restoring immune homeostasis. Over the last few decades, various immune-modulating nutrients have been identified, which interfere with IL6 gene expression. Currently, a broad range of phyto-pharmaceuticals with a claimed hormonal activity, called "phyto-estrogens", is recommended for prevention of various diseases related to a disturbed hormonal balance (i.e. menopausal ailments and/or prostate/breast cancer). In this respect, there is a renewed interest in soy isoflavones (genistein, daidzein, biochanin) as potential superior alternatives to the synthetic selective estrogen receptor modulators (SERMs), which are currently applied in hormone replacement therapy.

Equol, a metabolite of daidzein, inhibits bone loss in ovariectomized mice.
J Nutr. 2004.
Our results suggest that equol inhibits bone loss apparently without estrogenic activity in the reproductive organs of  mice without ovaries.

Effect of daidzein on cell growth, cell cycle, and telomerase activity of human cervical cancer in vitro.
 Int J Gynecol Cancer. 2004.
Phytoestrogens are some plant compounds exhibiting estrogen-like activities. However, some studies have shown that they also affect the growth of some nonhormone-dependent diseases. In this study, daidzein--one of the most common phytoestrogens--was used to investigate its effects on human cervical cancer cells HeLa in vitro. The inductive effects of apoptosis were more obviously observed in low-concentration groups. After HeLa cells were treated with daidzein, the expression of human telomerase catalytic subunit mRNA decreased. These meant that daidzein affected human nonhormone-dependent cervical cancer cells in several ways, including cell growth, cell cycle, and telomerase activity in vitro.

Daidzein together with high calcium preserve bone mass and biomechanical strength at multiple sites in ovariectomized mice.
Department of Nutritional Sciences, Faculty of Medicine, University of Toronto, Toronto, ON
The objective of this study was to determine the effects of purified daidzein in combination with high calcium (Ca) on preserving femur and lumbar vertebrae (LV1-LV4) bone mineral density (BMD) and biomechanical bone strength at three different sites (femur midpoint, femur neck and LV3) in ovariectomized mice. The results from this study suggest that the combination of daidzein and high Calcium favorably affect cortical and trabecular bone as indicated by femur and lumbar vertebrae BMD and biomechanical strength but much of this effect is mediated by the high Calcium diet. Further investigation is required to determine optimal dietary levels of daidzein and Ca with the long-term goal of developing a dietary strategy to prevent postmenopausal osteoporosis and related fragility fractures.

Clinical Characteristics and Pharmacokinetics of Purified Soy Isoflavones: Multiple-Dose Administration to Men with Prostate Neoplasia.
Nutr Cancer. 2004.
A phase I clinical trial was conducted to determine the safety, pharmacokinetic parameters, and efficacy of orally administered isoflavones (genistein and daidzein, potential cancer chemotherapeutic agents) over a 3-mo period in men with prostate neoplasia. Twenty men, ages 40 and above, with stage B, C, or D adenocarcinoma of the prostate were treated with a multiple-dose regimen of a soy isoflavone formulation (delivering approximately 300 or 600 mg/day genistein and half this much daidzein) for 84 days. The delivered dose of isoflavones was more than 10-fold higher than that typically taken by prostate cancer patients. In men with prostate cancer, relatively minor side effects of chronic isoflavone treatment were observed including some estrogenic effects (breast changes, increased frequency of hot flashes). Serum dehydroepiandrosterone was decreased by 31.7% (P = 0.0004) at the end of treatment. Except for those subjects whose prostate-specific antigen (PSA) values were below 0.4 ng/ml, subjects had a history of increasing PSA levels prior to the trial. This increase continued during the trial both while on soy isoflavones and after treatment was discontinued. On average the rate of rise accelerated after soy isoflavones were discontinued, but that difference did not attain statistical significance. Genistein and daidzein were rapidly cleared from plasma and excreted in urine. Pharmacokinetic data for chronic dose administration were similar to single-dose administration for the isoflavones investigated except that we observed slightly longer circulation time for daidzein.

Metabolism of daidzein by intestinal bacteria from rhesus monkeys (Macaca mulatta).
Comp Med. 2004.
The metabolism of daidzein by the fecal bacteria of nine monkeys was investigated. Daidzein was incubated anaerobically with fecal bacteria, and the metabolites were analyzed by use of liquid chromatography and mass spectrometry. The fecal bacteria of all of the monkeys metabolized daidzein to various extents. Dihydrodaidzein was found in cultures of fecal bacteria from two monkeys; dihydrodaidzein and equol were found in cultures from four monkeys; dihydrodaidzein, equol, and an unknown metabolite (MW = 244) were found in cultures from one monkey; and dihydrodaidzein and the unknown metabolite were found in cultures from two monkeys. Similar to that in humans, variation was evident in the metabolism of isoflavonoids by fecal bacteria from rhesus monkeys. Some metabolites produced by fecal bacteria from monkeys were the same as those produced by fecal bacteria from humans.

Dietary phytoestrogen intake and premenopausal breast cancer risk in a German case-control study.
Int J Cancer. 2004.
A diet high in isoflavonoids is associated with lower breast cancer risk in Asian populations. Due to the low soy intake, dietary lignans may be the more important phytoestrogen class in Western populations. We used a population-based case-control study of breast cancer by age 50 in southern Germany to evaluate the association between dietary intake of different phytoestrogens and premenopausal breast cancer risk. Our results suggest an important role of dietary intake of daidzein and genistein, despite low levels, as well as of matairesinol and mammalian lignans to reduce premenopausal breast cancer risk in this study population.

Q.  Is there a way to test if you are an equol producer? I'm an average Joe taking red clover twice a day (for hair loss) but also for prostate health. I would like to know if it's beneficial to me to keep taking this. Also, after reading a couple of the daidzein articles, I believe I have experienced my first "hot flash" the other night. It felt as though I was going to be sick, I got real hot then sweat on my forehead. I just thought I had caught a touch of the flu. Anyhow, I'm now thinking that I had a hot flash, because I'm taking too much daizden? hard to say, there aren't any guidelines for how much to take. Are the "herbal" drug companies any closer to creating an over the counter equol supplement so us thinning hair people can combat male pattern baldness?
   A. You ask good questions and we just don't have enough knowledge at this time to make any firm recommendations.

I would like to purchase isoflavone supplements. Just diagnosed with low grade prostate cancer but how do I know If I can metabolize diadzin to equol? Are there labs that can do this?
    This kind of evaluation is not routinely available to a patient, it is still specialized study mostly used by researchers.

Kudzu Recovery, 750 mg, 120 Tabs
Planetary Formulas
Botanical Support for Alcohol Cessation
Kudzu Recovery herbal supplement features the roots and flowers of kudzu (Pueraria lobata), which have long been used in Chinese herbal medicine to help lessen the desire for alcohol. Researchers have identified two constituents in kudzu responsible for this activity, puerarin, daidzein and daidzin, which in animal research have been found to cause a similar effect. These are combined with coptis, a primary cleansing and liver-supporting herb from Chinese herbalism, and other key botanicals to support botanicals historically used to reduce cravings.
Lifestyle Recommendations: To decrease cravings, maintain adequate caloric intake by eating regularly scheduled meals, avoid simple sugar, and supplement with chromium and B-complex vitamin. Avoid excess stress, exercise regularly, and promote a calm mental state of well-being.
Kudzu root, Kudzu flower, Hovenia fruit, Coptis chinensis root, Poria Cocos sclerotium, Grifola sclerotium, Atractylodes root, Codonopsis root, Saussurea root, Shen Qu-Massa Fermentata extract, Green Citrus peel, Cardamom fruit and Ginger root.