Phytoestrogens and risk of prostate cancer: a meta-analysis of observational studies.

Abstract

BACKGROUND:

Epidemiologic studies have reported various results relating phytoestrogens to prostate cancer (PCa). The aim of this study was to provide a comprehensive meta-analysis on the extent of the possible association between phytoestrogens (including consumption and serum concentration) and the risk of PCa.

METHODS:

Eligible studies were retrieved via both computer searches and review of references. The summary relative risk ratio (RR) or odds ratio (OR) and 95% confidence interval (CI) were calculated with random effects models.

RESULTS:

A total of 11 studies (2 cohort and 9 case-control studies) on phytoestrogen intake and 8 studies on serum concentration were included in the meta-analysis. The pooled odds ratio (OR) showed a significant influence of the highest phytoestrogens consumption (OR 0.80, 95% CI 0.70-0.91) and serum concentration (OR 0.83, 95% CI 0.70-0.99) on the risk of PCa. In stratified analysis, high genistein and daidzein intake and increased serum concentration of enterolactone were associated with a significant reduced risk of PCa. However, no significant associations were observed for isoflavone intake, lignans intake, or serum concentrations of genistein, daidzein, or equol.

CONCLUSIONS:

The overall current literature suggests that phytoestrogen intake is associated with a decreased risk of PCa, especially genistein and daidzein intake. Increased serum concentration of enterolactone was also associated with a significant reduced risk of PCa. Further efforts should be made to clarify the underlying biological mechanisms.

• Authors: Jinjing He, Shuai Wang, Mi Zhou, Weiwen Yu, Yuelong Zhang, Xiang He
• Journal: World journal of surgical oncology (World J Surg Oncol) Vol. 13 Pg. 231 (Jul 31 2015) ISSN: 1477-7819 [Electronic] England
• PMID: 26228387 (Publication Type: Journal Article, Meta-Analysis, Research Support, Non-U.S. Gov't)

Chemical References

• Phytoestrogens

Topics

• Case-Control Studies
• Humans
• Male
• Observational Studies as Topic
• Phytoestrogens (therapeutic use)
• Prostatic Neoplasms (etiology, prevention & control)
• Risk Factors