Diet and Rheumatoid Arthritis Symptoms: Survey Results From a Rheumatoid Arthritis Registry

Objective. Patients with rheumatoid arthritis (RA) often ask whether specific foods, popularized as inflammatory or antiinflammatory, can improve or worsen their RA. Patients with RA took a survey on diet and RA symptoms, and the survey data were collected and analyzed. Methods. A dietary survey was mailed to 300 subjects in a single-center RA registry at a large academic center. Subjects were asked about their consumption of 20 foods and whether these foods make their RA symptoms better, worse, or unchanged. Semiannual registry data include demographics, medications, comorbidities, and disease activity scores. Fisher's exact test and Wilcoxon's rank sum tests evaluated associations between subject characteristics from the most recent registry assessment and changes in RA symptoms from specific foods. Results. Of the 217 subjects (72% response rate), 83% were female; the median RA duration was 17 years (interquartile range 9-27 years), and 58% were taking a biologic disease-modifying antirheumatic drug. Twenty-four percent of subjects reported that foods affect their RA symptoms, with 15% reporting improvement and 19% reporting worsening. Blueberries and spinach were the foods most often reported to improve RA symptoms, while soda with sugar and desserts were those most often reported to worsen RA symptoms. Younger age and noting that sleep, warm room temperature, and vitamin/mineral supplements improve RA were each associated with reporting that foods affect RA symptoms. Medication use, sex, body mass index, smoking, disease duration, disease activity scores, and self-reported RA flares were not associated with reporting that foods affect RA. Conclusion. Nearly one-quarter of RA subjects with longstanding disease reported that diet had an effect on their RA symptoms.