Folate intake and risk of bladder cancer: a meta-analysis of epidemiological studies

Int J Food Sci Nutr. 2014 May;65(3):286-92. doi: 10.3109/09637486.2013.866641. Epub 2013 Dec 16.

Abstract

Epidemiological studies have reported conflicting results between folate intake and bladder cancer risk. We conducted a meta-analysis of epidemiological studies published between 1996 and June 2013 on the relationship between folate intake and bladder cancer. We quantified associations with bladder cancer using meta-analysis of risk estimates (REs) associated to the highest versus the lowest category of folate intake using random effect models. Seven cohort and six case-control studies were eligible for inclusion. A significantly decreased risk with bladder cancer was observed in overall folate intake group (RE = 0.84; 95% CI, 0.72-0.96) and subgroup of case-control studies (RE = 0.73; 95% CI, 0.57-0.89), but not in cohort studies (RE = 0.96; 95% CI, 0.81-1.10) when comparing the highest with the lowest category of folate intake. No heterogeneity and publication bias were observed across studies. Although the current evidence, mainly based on data from case-control studies, supports an inverse association between folate intake and bladder cancer, additional large and well-designed cohort studies are needed before definitive conclusions can be drawn.

Publication types

  • Meta-Analysis

MeSH terms

  • Folic Acid / therapeutic use*
  • Humans
  • Urinary Bladder Neoplasms / prevention & control*
  • Vitamin B Complex / therapeutic use*

Substances

  • Vitamin B Complex
  • Folic Acid