Journal
CANCER EPIDEMIOLOGY BIOMARKERS & PREVENTION
Volume 16, Issue 4, Pages 829-833Publisher
AMER ASSOC CANCER RESEARCH
DOI: 10.1158/1055-9965.EPI-06-0882
Keywords
-
Funding
- NCI NIH HHS [P30 CA72720-01-03] Funding Source: Medline
Ask authors/readers for more resources
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 testosteron e and luteinizing hormone (LH) levels were collected on days -7, 0, 14, and 28 of therapy, and day 42. A reporter estrogen receptor (ER) assay was used to determine the effect on ER-beta and ER-alpha in vitro. Results: Twelve subjects were enrolled with a mean age of 32.25 years (range 25 to 47). Serum testosterone decreased 19%( 22%) 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-beta using a reporter estrogen receptor assay in yeast. Conclusion: Soy protein powder decreases serum testosterone levels in healthy men and acts as an ER-beta agonist; the significance of this biological effect with respect to cancer prevention needs further study.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available