Effect of plant-and animal-based foods on prostate cancer risk

Context: Many studies have explored whether plant and animal-based food consumption is associated with prostate cancer (PCa) risk, but there is much discordance. Objective: To perform an updated review of the literature that further investigates the association of plant-and animal-based food consumption with PCa risk. Methods: This review was conducted by using 3 databases and produced a total of 550 references. The search was limited to a publication date range of 2006 to February 2017, English language, and humans. After case reports, comments, letters, editorials, and duplicate references were removed, 297 citations remained for review. Articles that did not investigate the association of dietary patterns or a major component of diet with PCa were excluded. Results: Of the 297 references found, 47 were eligible for inclusion in this review. The authors identified 2 very large cohort studies (≥100,000 participants), 6 large cohort studies (≥40,000 participants), 11 medium cohort studies (≥10,000 participants), 10 small cohort studies (<10,000 participants), 13 case-control studies, 4 meta-analyses, and 1 population study investigating diet and PCa risk. Most studies showed that plant-based foods are associated with either decreased or unchanged risk of PCa, whereas animal-based foods, particularly dairy products, are associated with either increased or unchanged risk of PCa. Conclusion: This review of the literature suggests that consumption of higher amounts of plant-based foods may be associated with decreased PCa risk, and consumption of higher amounts of dairy products may be associated with increased PCa risk.