Salted fish and processed foods intake and nasopharyngeal carcinoma risk: a dose-response meta-analysis of observational studies.

Abstract

This study aims to analyze whether the consumption of salted fish and processed foods increases the risk of nasopharyngeal carcinoma by analyzing the relevant case-control or cohort design. Major databases such as PubMed, ScienceDirect, Embase and Cochrane Library were searched to conduct related studies. In addition, Newcastle-Ottawa scale was employed for assessing the quality of articles. Random-effect model was utilized for meta-analysis. Total relative risk (RR) and 95% confidence interval (95% CI) were calculated. Dose response showed a consistent linear relationship between the intake of salted fish and processed foods and the risk of nasopharyngeal carcinoma. In salted fish, the summary RR was 1.23 (1.04-1.47) for low intake and 1.45 (1.19-1.76) for high intake. For processed meat, low intake was 1.33 (1.09-1.62) and high intake was 1.65 (1.35-2.02). Low intake of processed vegetables was 1.28 (1.05-1.55) and high intake was 1.45 (1.17 -1.79) for high intake. Significant heterogeneity existed in all data but decreased in some subgroups after subgroup analysis. Salted fish and processed foods are risk factors for increasing nasopharyngeal carcinoma, but they have different risk characteristics due to different intakes, different stages, and different types.