Phytoestrogens and risk of prostate cancer: an updated meta-analysis of epidemiologic studies

Abstract

This updated meta-analysis was performed to clarify the relationship between phytoestrogens and prostate cancer risk. Twenty one case–control and two cohort studies were finally selected for this meta-analysis, totaling 11,346 cases and 140,177 controls. Analytical results showed that daidzein (OR = 0.85; 95% CI: 0.75–0.96), genistein (OR = 0.87; 95% CI: 0.78–0.98), and glycitein (OR = 0.89; 95% CI: 0.81–0.98) were associated with a reduction of prostate cancer risk, but total isoflavones (OR = 0.93; 95% CI: 0.84–1.04), equol (OR = 0.86; 95% CI: 0.66–1.14), total lignans (OROgna.05; 95% CI: 0.54–2.04), secoisolariciresinol (OR = 1.02; 95% CI: 0.83–1.24), matairesinol (OR = 0.91; 95% CI: 0.75–1.11), enterolactone (OR = 0.94; 95% CI: 0.73–1.20), and coumestrol (OR = 0.89; 95% CI: 0.76–1.06) were not. Sensitivity and publication bias analyses demonstrated that the pooled estimates were stable and reliable. The results support the notion that some phytoestrogens may have a role in decreasing the risk of prostate cancer. Additional large and well-designed cohort studies are needed to confirm these relationships.

Keywords:

• Phytoestrogens
• prostate cancer
• meta-analysis
• isoflavones
• risk

Disclosure statement

The authors declare that they have no conflicts of interest.