Diet unlikely to ease progression of osteoarthritis, rheumat
The European League Against Rheumatism (EULAR) convened an international taskforce in 2018 to look at the potential impact of diet, exercise, weight, alcohol, smoking and paid work on disease progression, and develop appropriate recommendations for clinicians and patients for each of these behaviors. For the dietary recommendations, the taskforce searched for relevant systematic reviews of randomized controlled trials or observational studies and pooled data analyses looking at the impact of dietary components/supplements on pain, joint damage, and physical function for seven common rheumatoid and musculoskeletal conditions. These were: osteoarthritis; rheumatoid arthritis; systemic lupus erythematosus; axial spondyloarthritis; psoriatic arthritis; systemic sclerosis; and gout.

In all, 24 systematic reviews, published between 2013 and 2018, and 150 original research articles with no restriction on publication date, were included in the pooled data analysis. The pooled data analyses showed that for dietary interventions with moderate evidence (fish oil, chondroitin, glucosamine, vitamin D, avocado and soybean), the magnitude of the impact on disease progression was generally small and not clinically meaningful.

The evidence for most dietary interventions in rheumatoid arthritis was graded as poor or very poor, primarily because of the small number of studies and participants. There was moderate quality evidence for probiotics, vitamin D, fish oil/omega-3 but the impact was either negligible or too small to make much difference.

The evidence for fish oil/omega-3 for systemic lupus erythematosus was rated as moderate but showed no effect on outcomes. The evidence for all other studies on this condition was rated as poor or very poor, as it was for axial spondyloarthritis. Similarly, the evidence for fish oil/omega-3 for psoriatic arthritis was rated as moderate and showed no effect on outcomes. The evidence for other dietary interventions was rated as poor. The evidence for systemic sclerosis and gout was also rated as poor.