Folate intake, serum folate levels, and prostate cancer risk: a meta-analysis of prospective studies

Abstract

BackgroundStudies have reported inconsistent results concerning the existence of associations of folate intake and serum folate levels with prostate cancer risk. This study sought to summarise the evidence regarding these relationships using a dose–response meta-analysis approach.MethodsIn January 2014, we performed electronic searches of PubMed, Embase, and the Cochrane Library to identify studies examining the effect of folate on the incidence of prostate cancer. Only prospective studies that reported effect estimates with 95% confidence intervals (CIs) of the incidence of prostate cancer for more than 2 categories of folate were included.ResultsOverall, we included 10 prospective studies reporting data on 202,517 individuals. High dietary folate intake had little or no effect on prostate cancer risk (risk ratio [RR] = 1.02; 95% CI = 0.95–1.09; P = 0.598). The dose–response meta-analysis suggested that a 100 μg per day increase in dietary folate intake has no significant effect on the risk of prostate cancer (RR = 1.01; 95% CI = 0.99–1.02; P = 0.433). However, high serum folate levels were associated with an increased risk of prostate cancer (RR = 1.21; 95% CI = 1.05–1.39; P = 0.008). The dose–response meta-analysis indicated that a 5 nmol/L increment of serum folate levels was also associated with an increased risk of prostate cancer (RR = 1.04; 95% CI = 1.00–1.07; P = 0.042).ConclusionsOur study indicated that dietary folate intake had little or no effect on prostate cancer risk. However, increased serum folate levels have potentially harmful effects on the risk of prostate cancer.Electronic supplementary materialThe online version of this article (doi:10.1186/1471-2458-14-1326) contains supplementary material, which is available to authorized users.

Guidelines for the diagnosis and management of cystathionine beta‐synthase deficiency

“…We recommend giving all patients low-dose folate supplements and monitoring their vitamin B 12 levels. High dose folate therapy may lead to an additional benefit through enhancing the remethylation pathway but may have side effects (Wang et al 2014). Though it is clear that folate deficiency must be avoided, there is little evidence concerning the optimal dose of folate supplementation.…”

Dietary Nutrient Patterns and Prostate Cancer Risk: A Case-Control Study from Iran

“…Numerous studies have shown the protective effects of vitamin K and carotenoids consumption on prostate cancer risk (Nimptsch et al, 2008;Nimptsch et al, 2015;Dasari et al, 2017), However there is conflicting evidence regarding folate intake and prostate cancer risk. Some Studies found no association between dietary and total folate intake and prostate cancer risk, while other studies reported that higher blood folate levels increased prostate cancer risk (Figueiredo et al, 2009;Wang et al, 2014). It is possible that synergistic effect of other nutrients in this pattern, cause the significant effect of folate on reducing the risk of prostate cancer, that is completely in line with our hypothesis based on the effect of interactions between nutrients and the predominance of the effect of a higher consumption of nutrients that exhibit behavioural coexistence.…”

Cáncer de colon y su relación con la fortificación de ácido fólico

“…También cabe destacar que si bien no fue el objetivo de esta revisión, en la literatura se describen asociaciones entre la ingesta de folatos con modificaciones del riesgo de otros tipos de cáncer como pancreático 24,25 , cáncer de próstata 26,27 , cáncer de cavidad oral y faringe 28 , cáncer mamario [29][30][31][32][33] , cáncer pulmonar 34,35 , cáncer de vejiga 36 , cáncer gastrointestinal 37 , por lo que se sugiere considerar en el análisis del programa de fortificación nacional con ácido fólico.…”