Dietary Inflammatory Index and Risk of Esophageal Squamous Cell Cancer in a Case-Control Study from Iran

Abstract

Diet and inflammation have been suggested to be important risk factors for esophageal squamous cell carcinoma (ESCC). In this study, we examined the ability of the dietary inflammatory index (DII) to predict ESCC in a case-control study conducted in Iran. This study included 47 ESCC cases and 96 controls hospitalized for acute nonneoplastic diseases. The DII was computed based on dietary intake assessed by a previously validated food frequency questionnaire. Logistic regression models were used to estimate odds ratios (ORs) adjusted for age, energy, sex, body mass index, years of education, physical activity, smoking and gastroesophageal reflux. Subjects with higher DII scores (i.e., with a more proinflammatory diet) had a higher risk of ESCC, with the DII being used as both a continuous variable [OR_continuous = 3.58, 95% confidence interval (CI): 1.76–7.26; one unit increase corresponding to ≈16% of its range in the current study] and a categorical variable (OR_{dii>1.20 vs ≤1.20} = 8.24, 95% CI: 2.03–33.47). These results indicate that a proinflammatory diet is associated with increased risk of ESCC.

ACKNOWLEDGMENTS

We are grateful to all field investigators, staffs and participants of the present study. James R. Hébert owns controlling interest in Connecting Health Innovations LLC (CHI), a company planning to license the right to his invention of the dietary inflammatory index (DII) from the University of South Carolina in order to develop computer and smart phone applications for patient counseling and dietary intervention in clinical settings. Dr. Nitin Shivappa is an employee of CHI. The subject matter of this article will have no direct bearing on the work of CHI, nor has any CHI-related activity exerted any influence on this project.

FUNDING

This study was supported by a grant from National Nutrition and Food Technology Research Institute, Shahid Beheshti University of Medical Sciences, Tehran, IRAN. Drs. Shivappa and Hébert were supported by grant number R44DK103377 from the United States National Institute of Diabetes and Digestive and Kidney Diseases.