Citrus fruit intake and the risk of nasopharyngeal carcinoma.

Abstract

Citrus fruit are suggested to be associated with reduced risk of nasopharyngeal carcinoma (NPC), but findings from epidemiologic studies have been inconsistent. We aimed to synthesize the association by conducting a meta-analysis of existing evidence. Databases including Medline, EMBASE, Web of science, and the Cochrane Library were searched for eligible studies up to March 2019 using a series comprehensive searching terms. The adjusted odds ratios (ORs) of citrus fruit intake with NPC risk from each study were extracted to calculate a pooled association estimate with its 95% confidence interval (CI). Nine studies totaling 3304 cases and 3850 controls were included in this analysis. Citrus fruit intake was significantly associated with reduced risk of NPC (OR: 0.72, 95% CI 0.58-0.91, p=0.005). In addition, this association tended to be stronger in Chinese (OR: 0.67, 95% CI 0.54-0.84, p<0.001). Dose-response analysis using cubic splines showed the risk of NPC decreased by 21% for citrus fruit intake of 4 times/week (OR: 0.79, 95% CI 0.66-0.94). Consumption of citrus fruit was associated with a significantly reduced risk of NPC, especially in Chinese.