The effect of flavonoid and subclasses supplementation on prostate specific antigen, hormonal parameters and prostate cancer risk: a systematic review and meta-analysis of randomized controlled trials.

Abstract

Introduction and objectives: Prostate cancer (PCa) is a significant concern and burden worldwide. Several studies suggest that flavonoids have a significant potential as an anti-cancer agent, but the evidence remains controversial. This study aims to assess the effect of flavonoids and its subclasses supplementation on PCa risk parameters in men with biopsy-proven diagnosis of PCa or clinically determined to have a high risk of PCa.

Materials and methods: This systematic review and meta-analysis adhered to PRISMA guideline. A literature search was conducted across PubMed, ScienceDirect, Scopus and Cochrane utilizing PICO framework. Revised Cochrane's risk of bias tools (RoB2) was used for quality analysis. Review manager 5.4 was used for statistical analysis.

Results: Out of 1.117 articles, nine final studies (involving 420 patients) were included. Regarding total PSA, flavonoid provided a reduction of total PSA (MD: -0.64, p<0.05), and sub-group analysis based on the supplementation duration showed flavonoid administration with a duration of ≥12 weeks significantly reduced total PSA compared to administration of <12 weeks (p<0.05). Meta-analyses of four studies, including men clinically at risk of PCa, revealed that flavonoid supplementation was associated with a significantly lower risk of developing PCa at endpoint (OR 0.41, p<0.05). However, our results indicated no favorable effect on hormonal parameters.

Conclusions: The results of this meta-analysis suggest there may be a potential role for flavonoid in PCa risk reduction. Flavonoids supplementation also have been proven to be safe. However, further investigation is necessary to gain a clear understanding of the flavonoid impact on PSA and sex hormone parameters.