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

The aim of the study was to assess the association between total flavonoids/flavonoid subclasses intake and prostate cancer risk. Several databases were searched to select eligible studies with predefined criteria.

Risk ratios (RRs) with 95% confidence intervals (CIs) were used as the effect size. Publication bias and sensitivity analysis were performed. A total of five studies including four prospective cohort studies and one case-control study were included in the meta-analysis. The pooled result demonstrated a significantly increased risk of prostate cancer with higher intake of total flavonoids (RR = 1.12, 95% CI: 1.02-1.23, P = 0.013). However, sensitivity analysis indicated that there lacked a significant association after removing the study of Wang et al. (RR = 1.17, 95% CI: 0.94-1.46). Subgroup analysis stratified by flavonoids subclasses found that higher intake of anthocyanidins and flavan-3-ols were significantly associated with increased prostate cancer risk (RR = 1.12, 95% CI: 1.03-1.21, P = 0.011; RR = 1.21, 95% CI: 1.10-1.32, P < 0.001). Sensitivity analysis also indicated that after removing Wang's study, no significant association between anthocyanidins intake and prostate cancer risk was detected (RR = 1.22, 95% CI: 0.97-1.54). In conclusion, higher intake of flavonoids may not be associated with prostate cancer risk.

Andrologia. 2016 Mar 15 [Epub ahead of print]

K Guo, Z Liang, L Liu, F Li, H Wang

Department of Andrology, The First Hospital of Jilin University, Changchun, China., Department of Andrology, The First Hospital of Jilin University, Changchun, China., Department of Andrology, The First Hospital of Jilin University, Changchun, China., Department of Andrology, The First Hospital of Jilin University, Changchun, China., Department of Andrology, The First Hospital of Jilin University, Changchun, China.