Supplementary Material for: The intake of cruciferous vegetables and the risk of ovarian cancer: a systematic review and dose-response meta-analysis

Introduction: The link between cruciferous vegetables (CVs) and ovarian cancer (OC) is still uncertain. This meta-analysis intended to investigate the association between CVs consumption and the risk of OC, as well as to conduct a dose-response analysis to determine the degree of correlation between them. Methods: We systematically searched PubMed, Web of Science, Embase, and Cochrane Library databases between database creation and October 2023. The present meta-analysis has been duly registered and assigned the registration number CRD42023470299. This study followed the PRISMA guidelines. The statistical analysis was performed using Stata 14.0 software. Results: There were a total of 7 cohort studies and 7 case-control studies with 7,269 cases and 742,952 subjects. The combined relative risk (RR) of the highest intake of CVs was 0.90 (95% confidence intervals [CIs]: 0.84-0.96; I2=54.7%; P=0.007) compared to the lowest intake of CVs. The odds ratio (OR) was 0.97 (95% CIs: 0.86–1.08; P=0.192) for case–control studies, and the RR was 0.79 (95% CIs: 0.67–0.91; P=0.167) for cohort studies. The intake of CVs and the risk of OC were linearly correlated. Adding 15 grams of CVs to the diet each day decreased the likelihood of developing OC by almost 4% (RR=0.963, 95% CIs: 0.905-1.025; P=0.235). Conclusions: Consumption of CVs may be linked to a lower risk of OC.