Consumption of processed food and risk of nasopharyngeal carcinoma: a systematic review and meta-analysis

BACKGROUND: Consumption of processed foods has been associated with nasopharyngeal carcinoma (NPC), but with inconsistent results. Therefore, we conducted a systematic review and meta-analysis to compute results regarding the association between processed foods and risk of NPC in included studies. METHODS: Studies exploring the association between consumption of processed food and risk of NPC were included in the present study. All included studies were case-control or cohort designed. PubMed, Web of Science, EMBASE, Medline and Google Scholar databases were searched for articles published before July 2021. We recorded the following data: author, publication year, sample size, study type, study location, years of diagnosis, food item and comparison, and the covariates considered were multivariate adjusted odds ratios (ORs) or relative risks (RRs) with corresponding 95% confidence intervals (CIs) for the highest vs. lowest categories of processed food intake. STATA 12.0 software was used to compute the multivariate ORs or RRs and 95% CIs of the association. Quality appraisal was made using the Cochrane Risk of Bias Tool. RESULTS: A meta-analysis was made for 29 case-control studies (including 14,378 NPC patients and 17,928 controls). The meta-analysis showed that the highest categories of processed food intake were associated with a 65% increase in NPC risk compared with the lowest categories in a random effects model (OR =1.67; 95% CI: 1.56–1.79; P value for Q test <0.001; I(2)=86.9%). Subgroup study showed significant positive associations regarding consumption of processed food and risk of NPC in both Asians and Caucasians (Asian: OR =1.68, 95% CI: 1.56–1.81; Caucasian: OR =1.36, 95% CI: 1.09–1.71). CONCLUSIONS: The association of processed foods with NPC risk might be significant. Further prospective studies and experimental research are needed to explore this relationship.