Adherence to the dietary approaches to stop hypertension dietary pattern and rheumatoid arthritis in Iranian adults.

Objective: To examine the hypothesis that rheumatoid arthritis (RA) patients are less likely than healthy individuals to adhere to the dietary approaches to stop hypertension (DASH) dietary pattern.

Design: A multi-centre cross-sectional study involving a total of 300 eligible Iranian adults (aged >19 years; 93·0 % female) recruited during 2019-2020. Participants' actual dietary intakes were measured via self-administered 3-d dietary records. The DASH score was computed based on the energy-adjusted intakes of eight major dietary components usually emphasised (i.e. fruits, vegetables, nuts and legumes, low-fat dairy products and whole grains) or minimised (i.e. sweets, red or processed meats and sodium) in the DASH diet. The higher the DASH score of subjects, the greater their adherence to the DASH pattern.

Setting: The outpatient clinics of major general hospitals in Shiraz, Iran.

Participants: 100 incident cases with definite RA according to the 2010 American College of Rheumatology/European League Against Rheumatism Classification Criteria for RA and 200 apparently healthy controls frequency-matched by gender and age.

Results: After adjusting for several potential covariates in the binary logistic regression analysis, RA cases were less likely than controls to have high adherence to the DASH pattern (OR = 0·08; 95 % CI 0·03, 0·20; P = 0·001).

Conclusions: Our findings in a sample of Iranian adults revealed that RA patients are less likely than healthy individuals to adhere to the DASH dietary pattern. However, the potential causal association of greater adherence to the DASH pattern and lower risk of RA needs to be confirmed by prospective studies of high methodological quality.