Inverse Association of Soy Product Intake With Serum Androgen and Estrogen Concentrations in Japanese Men

Nagata, Chisato; Inaba, Shizuyo; Kawakami, Norito; Kakizoe, Tadao; Shimizu, Hiroyuki

doi:10.1207/s15327914nc3601_3

Cited by 96 publications

(53 citation statements)

References 33 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Isoflavones possess weak estrogen activity, inhibit tyrosine protein kinases and angiogenesis, and reduce serum testosterone levels (6,28,29). Isoflavones also inhibit 5a-reductase, an enzyme that metabolizes testosterone to dihydrotestosterone (30).…”

Section: Discussionmentioning

confidence: 99%

Soy Product and Isoflavone Consumption in Relation to Prostate Cancer in Japanese Men

Kurahashi¹,

Iwasaki²,

Sasazuki³

et al. 2007

Cancer Epidemiology, Biomarkers &Amp; Prevention

189

133

View full text Add to dashboard Cite

The incidence of prostate cancer is much lower in Asian than Western populations. Environmental factors, such as dietary habits, may play a major role in the causation of prostate cancer. Although isoflavones have been suggested to show a preventive effect against prostate cancer in animal experiments, the results of epidemiologic studies are inconsistent. Here, we conducted a population-based prospective study in 43,509 Japanese men ages 45 to 74 years who generally have a high intake of isoflavones and low incidence of prostate cancer. Participants responded to a validated questionnaire, which included 147 food items. During follow-up from 1995 through 2004, 307 men were newly diagnosed with prostate cancer, of which 74 cases were advanced, 220 cases were organ localized, and 13 cases were of an undetermined stage. Intakes of genistein, daidzein, miso soup, and soy food were not associated with total prostate cancer. However, these four items decreased the risk of localized prostate cancer. In contrast, positive associations were seen between isoflavones and advanced prostate cancer. These results were strengthened when analysis was confined to men ages >60 years, in whom isoflavones and soy food were associated with a dose-dependent decrease in the risk of localized cancer, with relative risks for men in the highest quartile of genistein, daidzein, and soy food consumption compared with the lowest of 0.52 [95% confidence interval (95% CI), 0.30-0.90], 0.50 (95% CI, 0.28-0.88), and 0.52 (95% CI, 0.29-0.90), respectively. In conclusion, we found that isoflavone intake was associated with a decreased risk of localized prostate cancer. (Cancer Epidemiol Biomarkers Prev 2007;16(3):538 -45)

show abstract

Section: Discussionmentioning

confidence: 99%

Soy Product and Isoflavone Consumption in Relation to Prostate Cancer in Japanese Men

Kurahashi¹,

Iwasaki²,

Sasazuki³

et al. 2007

Cancer Epidemiology, Biomarkers &Amp; Prevention

189

133

View full text Add to dashboard Cite

show abstract

“…Studies focusing on hormonal levels also found no clear effects (or borderline significance) when consuming tofu (70 mg/day isoflavones), soymilk (48 mg/day isoflavones), or soy products (22 mg/day isoflavones; Habito et al, 2000;Nagata et al, 2000Nagata et al, , 2001. A recent meta-analysis, which included studies that evaluated testosterone levels as a bio-indicator of risks for prostate cancer, suggested out of 32 reports that soy foods or isoflavone intake do not alter free testosterone levels (Hamilton-Reeves et al, 2010).…”

Section: Soy Phytoestrogens and Male Reproductive Functionmentioning

confidence: 99%

Soy, phytoestrogens and their impact on reproductive health

Cederroth

Zimmermann

Nef

2012

Molecular and Cellular Endocrinology

193

117

View full text Add to dashboard Cite

a b s t r a c tThere is growing interest in the potential health threats posed by endocrine-disrupting chemicals (EDCs) to the reproductive system. Soybean is the most important dietary source of isoflavones, an important class of phytoestrogen. While consumption of soy food or phytoestrogen supplements has been frequently associated with beneficial health effects, the potentially adverse effects on development, fertility, and the reproductive and endocrine systems are likely underappreciated. Here we review the available epidemiological, clinical and animal data on the effects of soy and phytoestrogens on the development and function of the male and female reproductive system, and weigh the evidence as to their detrimental impact.

show abstract

“…In healthy males, various soy formulations have been evaluated in several studies to determine its effectiveness in decreasing testosterone and ultimately its role in reducing the risk of prostate cancer (15)(16)(17)(18)(19)(20)(21)(22). Most of these studies did not document a significant reduction in circulating testosterone, with the exception of the study by Gardner-Thorpe (18), which used a high concentration of soy isoflavone, and the study by Dillingham (22), which showed a minor reduction of hormone levels.…”

Section: Discussionmentioning

confidence: 99%

Clinical and Biological Activity of Soy Protein Powder Supplementation in Healthy Male Volunteers

Goodin

Shen

Shih

et al. 2007

Cancer Epidemiology, Biomarkers &Amp; Prevention

View full text Add to dashboard Cite

Purpose: To determine if a commonly used soy protein supplement exhibits biological activity in vivo and in vitro, we evaluated an over-the-counter soy protein powder supplement using blood from healthy male volunteers and in an estrogen receptor in vitro assay. Subjects and Methods: We recruited healthy male volunteers 18 years of age or older that were in good health. Treatment consisted of consuming two scoops (56 g) of pure soy protein powder (Puritan's Pride, Oakdale, NY) daily for 28 days. Serum testosterone and luteinizing hormone (LH) levels were collected on days À7, 0, 14, and 28 of therapy, and day 42. A reporter estrogen receptor (ER) assay was used to determine the effect on ER-B and ER-A in vitro. Results: Twelve subjects were enrolled with a mean age of 32.25 years (range 25 to 47). Serum testosterone decreased 19%(F22%) during the 4-week use of soy protein powder (P = 0.021) and increased within 2 weeks after we discontinued soy protein powder. Serum LH concentrations decreased during the 4-week use of soy protein powder then increased within 2 weeks after we stopped the soy protein powder, but the changes did not reach statistical significance (P = 0.20). Soy protein powder was found to induce agonist activity to ER-B using a reporter estrogen receptor assay in yeast. Conclusion: Soy protein powder decreases serum testosterone levels in healthy men and acts as an ER-B agonist; the significance of this biological effect with respect to cancer prevention needs further study. (Cancer Epidemiol Biomarkers Prev 2007;16(4):829 -33)

show abstract

Inverse Association of Soy Product Intake With Serum Androgen and Estrogen Concentrations in Japanese Men

Cited by 96 publications

References 33 publications

Soy Product and Isoflavone Consumption in Relation to Prostate Cancer in Japanese Men

Soy Product and Isoflavone Consumption in Relation to Prostate Cancer in Japanese Men

Soy, phytoestrogens and their impact on reproductive health

Clinical and Biological Activity of Soy Protein Powder Supplementation in Healthy Male Volunteers

Contact Info

Product

Resources

About