Fruits and vegetables and cervical cancer: a systematic review and meta-analysis

We conducted a meta-analysis to examine the association of fruits and vegetables intake with the occurrence of cervical intraepithelial neoplasia (CIN) and invasive cancer. MEDLINE, LILACS, Scopus, Cochrane Library, and Web of Science databases and gray literature on Google Scholar were searched before December 17, 2018. Odds ratio (OR) or relative risk (RR) estimates for the highest vs. the lowest intake of intake and 95% confidence intervals (CI) from the included studies were pooled using fixed and random-effects models. We found 18 studies: 17 case-control studies (n = 9,014 cases, n = 29,088 controls) and one cohort study (n = 299,651). No association was observed for CIN. The pooled adjusted ORs (95% CI) for cervical cancer were 0.61 (95% CI 0.52-0.73) for vegetables and 0.80 (95% CI 0.70-0.93) for fruits. However, no association was observed when the pooled effect was estimated among studies that adjusted for human papillomavirus (HPV). Consumption of vegetables and fruits was not associated with incidence of cervical cancer among studies that controlled for HPV infection. The level of evidence is limited because only one cohort study was included in the analysis.