AUTHOR=Huang Yiping , Wang Wenyan , Jin Jianxiang 

TITLE=Association between polyphenol subclasses and prostate cancer: a systematic review and meta-analysis of observational studies

JOURNAL=Frontiers in Nutrition

VOLUME=11

YEAR=2024

URL=https://www.frontiersin.org/journals/nutrition/articles/10.3389/fnut.2024.1428911

DOI=10.3389/fnut.2024.1428911

ISSN=2296-861X

ABSTRACT=<sec id="sec1"><title>Background</title><p>The effect of polyphenol subclasses on prostate cancer (PCA) is controversial. Therefore, the purpose of this study was to investigate the relationship between polyphenol subclasses and PCA incidence.</p></sec><sec id="sec2"><title>Methods</title><p>From the establishment of the database to December 2023, a systematic search was conducted on PubMed, Web of Science, Embase, and Cochrane Library to identify relevant observational studies. The adjusted odds ratio (OR) and corresponding 95% confidence interval (95% CI) were used to assess the association.</p></sec><sec id="sec3"><title>Results</title><p>A total of 38 studies (11 were cohort studies and 27 were case–control studies), composing 824,933 participants, were included in this meta-analysis after excluding irrelevant records. The findings of the study revealed that men who consumed dietary polyphenols had a significantly higher risk of PCA compared to those who never or rarely consumed dietary polyphenols (OR = 1.01, <italic>p</italic> = 0.023), especially dietary flavonol (OR = 1.05, <italic>p</italic> = 0.042), flavanol (OR = 1.03, <italic>p</italic> = 0.026) and anthocyanin (OR = 1.06, <italic>p</italic> = 0.001). Neither total nor subclasses of dietary polyphenols have an effect on non-localized or high-grade PCA (OR = 1.01, <italic>p</italic> = 0.518). Dietary isoflavones tended to reduce the incidence of local or low-grade PCA, although there was no statistically significant difference (OR = 1.00, <italic>p</italic> = 0.081). Regarding serum/plasma polyphenol, total polyphenol (OR = 0.95, <italic>p</italic> = 0.002), genistein (OR = 0.92, <italic>p</italic> = 0.029) and enterolactone (OR = 0.92, <italic>p</italic> = 0.022) can reduce the incidence of PCA. No association was observed between total/subclasses of urinary polyphenols and PCA risk.</p></sec><sec id="sec4"><title>Conclusion</title><p>Polyphenols seem to generally increase the risk of PCA in the male population. The effect of polyphenols on PCA is affected by factors such as polyphenol subclasses, their forms (serum/plasma, urinary, dietary), and PCA-related factors (like PCA stage).</p></sec><sec id="sec401"><title>Systematic review registration</title><p>identifier: CRD42022322699.</p></sec>