Intake of cruciferous vegetables is associated with reduced risk of ovarian cancer: a meta-analysis

Background: Epidemiological studies on the association between cruciferous vegetable (CV) consumption and the risk of ovarian cancer have demonstrated inconsistent results. We conducted a meta-analysis on CV consumption and ovarian cancer risk. Methods: The relevant studies were identified by searching the Medline (Pubmed), Embase and Web of Science databases. The references of related articles and reviews up to October 2013 were also screened. The pooled relative risks (RRs) with 95% confidence intervals (CIs) for the highest versus the lowest CV consumption levels were calculated using a random-effects model. The heterogeneity and publication bias were also evaluated. Results: Eight studies (4 case-control studies and 4 cohort studies) were identified and included in this meta-analysis. When all studies were pooled together, there was a significantly inverse association between CV consumption and the risk of ovarian cancer (RR: 0.89; 95% CI: 0.81-0.99). No significant heterogeneity or publication bias was found. Conclusions: The findings from this study suggest that the consumption of CVs may reduce the risk of ovarian cancer. Further investigations are needed to confirm the clinical effect of CVs on ovarian cancer.