Association between dietary flavonoids intake and prostate cancer risk: A case-control study in Sicily

Objectives: The aim of this study is to test the association between dietary flavonoids intake and prostate cancer (PCa) in a sample of southern Italian individuals. Design: A population-based case–control study on the association between PCa and dietary factors was conducted from January 2015 to December 2016, in a single institution. Setting: Patients with elevated PSA (Prostate Specific Antigen) and/or suspicion of PCa underwent transperineal prostate biopsy (≥12 cores). A total of 118 histopathological-verified PCa cases were collected and matched with controls, which were selected from a sample of 2044 individuals randomly recruited among the same reference population. Finally, a total of 222 controls were selected. Main outcome measures: Prevalence of PCa. Results: Consumption of certain groups of flavonoids significantly differed between controls and cases, in particular: flavonols (63.36 vs 37.14 mg/d, P < 0.001), flavanols (107.61 vs. 74.24 mg/d, P =.016), flavanones (40.92 vs. 81.32 mg/d, P < 0.001), catechins (63.36 vs. 36.18 mg/d, P =.006). In the multivariate model, flavanols and flavones were associated with reduced risk of PCa, despite not in the highest quartile of intake. Higher flavonol and catechin intake was consistently associated with reduced risk of PCa (Odds Ratio (OR) = 0.19, 95% CI: 0.06–0.56 and OR = 0.12, 95% CI: 0.04–0.36). In contrast, the highest intake of flavanones was positively associated with PCa. Conclusion: Flavonols and catechins have proved to be the most promising molecules for a potential protective role against PCa. Nevertheless, further research on flavanones is needed to better establish whether they are associated with PCa.