Diet therapy for rheumatoid arthritis. A controlled double-blind study of two different dietary regimens.

Objective: To evaluate the effects of a diet therapy in patients with rheumatoid arthritis (RA).

Methods: Fifty RA patients entered a 24-week double-blind, randomised, controlled-study of two different dietary regimens (an experimental diet high in unsaturated fats, low in saturated fats with hypoallergenic foods vs. a control well-balanced diet). The primary end points of the study were 20% and 50% improvement in disease activity according to composite symptoms (Paulus index) of arthritis. Other end points were the other measures of disease activity at 12 and 24 weeks of diet treatment.

Results: The 2 groups were comparable at inclusion. Diet treatment was well tolerated and the rate of drop-outs was low. Percentage of patients with global 20 or 50% response didn't differ between experimental and control group after the 24-week of diet treatment. The experimental diet group did better for all the variables considered but only four variables (Ritchie's index, tender and swollen joints, and ESR) reached a statistical difference by multivariate analysis. Adjusting these data for weight variations, the number of tender joints (p=0.014) and ESR (p=0.025) were still statistically significant.

Conclusions: Dietary manipulation, either by modifying food supplements or by reducing weight, may give some clinical benefit although no significant improvement can be observed assessing the results with a composite index.