Western and Healthy Dietary Patterns and Risk of Rheumatoid Arthritis: A Case-Control Study

The association between dietary insulin index and dietary insulin load with rheumatoid arthritis

This study was designed to assess the relationship between dietary insulin index (DII) and dietary insulin load (DIL) and rheumatoid arthritis (RA) risk in a case-control study. This study enrolled ninety-five newly diagnosed RA patients and 200 age- and sex-matched healthy controls. Dietary intakes were assessed using a validated 168-item semi-quantitative FFQ. DII and DIL were calculated using food insulin index values from previously published data. In the unadjusted model, individuals in the highest DIL tertile had the significantly higher odds of RA than those in the lowest tertile of the DIL scores (OR = 1·32, 95 % CI (1·15, 1·78), Pfor trend = 0·009). After adjusting for confounders, the risk of RA was 2·73 times higher for participants in the highest tertile of DIL than for those in the lowest tertile (OR = 2·73, 95 % CI (1·22, 3·95), Pfor trend < 0·001). In addition, patients in the highest DII tertile had higher risk of RA than those in the first tertile (OR = 2·22, 95 % CI (1·48, 3·95), Pfor trend = 0·008). This association persisted after adjusting for potential confounders (OR = 3·75, 95 % CI (3·18, 6·78), Pfor trend = 0·002). Our findings suggest that diets high in DII and DIL may increase the risk of developing RA, independent of other potential confounders. These findings can be verified by more research, particularly with a prospective design.

Major dietary patterns and food groups in relation to rheumatoid arthritis in newly diagnosed patients

BACKGROUND

Evidence suggests that dietary patterns might act as environmental triggers in the development of chronic disorders such as rheumatoid arthritis (RA). However, data regarding the relationship between food patterns and RA are still limited and conflicting. In the current study, the authors aim to evaluate a link between major dietary patterns and RA in new case patients.

METHODS

This study was conducted in a case-control manner on 50 patients with newly diagnosed RA and 100 healthy individuals living in Mashhad, Iran. The individuals' dietary intake was assessed using a validated food frequency questionnaire (FFQ). The major dietary patterns were identified using factor analysis based on data from FFQ. Multivariable-adjusted logistic regression models were used to measure the associations between patterns and RA.

RESULTS

Three major dietary patterns were identified. High-level adherence to Western pattern had a positive association with RA (multivariable-adjusted OR tertile 3 vs. 1:1.95; 95% CI: 1.09-3.92; p-trend: .046), while the healthy pattern was inversely related to RA (multivariable-adjusted OR tertile 3 vs. 1:0.12; 95% CI: 0.03-0.44; p-trend: .001). No significant association was observed between the traditional pattern and RA.

CONCLUSIONS

Our findings revealed that people with dietary behaviors close to the Western dietary pattern are more likely to develop the disease. However, adhering to healthy and well-balanced dietary patterns rich in whole grains, low-fat dairies, white meats, eggs, fruits, vegetables, tea, and vegetable oils was found to be inversely correlated with the risk of RA.