Factors associated with dietary practices and beliefs on food of patients with rheumatic and musculoskeletal diseases: A multicentre cross-sectional study.

Objectives: To investigate dietary practices and beliefs of patients with rheumatic and musculoskeletal diseases (RMDs) and associated factors.

Methods: In 2019-2020, a cross-sectional multicentre study enrolled patients with inflammatory arthritis (IA) (rheumatoid arthritis [RA], axial spondyloarthritis [axSpA]) or hand osteoarthritis (HOA) from secondary- and tertiary-care centres. A self-administered questionnaire explored dietary practices and patients' perceived effects of diet, foods and beverages on symptoms. Univariable and multivariable analyses investigated factors associated with diets and patients' views.

Results: Of 448 included patients, data for 392 were analysed (123 with RA, 161 with axSpA, 108 with HOA), 26% were on or had been on at least one exclusion diet (mostly cow's milk- and gluten-free diets in IA, mostly cow's milk-free diet and detox/fasting in HOA). Only 5% of patients followed the Mediterranean diet. Among patients who had tried a diet, 51% reported a decrease in pain. Overall, 42% of patients identified at least one food or beverage that increased or decreased pain. On multivariable analyses, dieting or the perceived effect of food on pain was associated with health beliefs (positive or negative), the use of complementary and alternative medicines, and lack of support or information from healthcare professionals. Patients had received little dietary information from their physicians.

Conclusions: This study provides insights into patients' dietary practices and factors associated with these practices, including patients' health beliefs and insufficient support by health professionals, in RMDs.