The impact of dietary habits on the pathogenesis of rheumatoid arthritis: a case-control study.

It has not been clear what kinds and how much nutrients could be harmful, preventive, or healthful for development of rheumatoid arthritis. This study aimed to determine the impact of dietary habits on the pathogenesis of rheumatoid arthritis. This case-control study was conducted on a total of 500 rheumatoid arthritis patients and 500 healthy controls refereed to three clinics of Shiraz University of Medical Sciences in 2015-2016. Convenience sampling was used for data collection in both case and control groups. An approved valid and reliable questionnaire including information about the intake of different kinds of beverages, and nutritious and non-nutritious diet was used. Data were analyzed by SPSS, version 20, using t test, chi-square and Multiple Logistic Regression model. The associations between rheumatoid arthritis development and variables including drinking 1-7 cups of coffee (OR = .44, CI .25-.76), ≥ 8 cups of coffee (OR = .50, CI .28-.90), full-fat milk (OR = 1.01, CI 1.003-1.03) per month, and intake of green tea (OR = .65, CI .45-.93) and solid oils (OR = 2.29, CI:1.57-3.34) were significant. Based on the findings, coffee consumption more than one cup per month and green tea might have preventive effects on developing rheumatoid arthritis. On the other hand, patients who consumed more full-fat milk per month and solid oil might be at risk of development of rheumatoid arthritis. Therefore, modification of diet based on these findings is suggested. Performing a cohort study to determine the causality effect of dietary habits and development and prevention of rheumatoid arthritis is recommended.