Higher vitamin D, omega-3 FA intakes linked to better treatment results in early RA
Higher intake of dietary vitamin D and omega-3 fatty acids (FA) may potentially boost the treatment effect of disease-modifying antirheumatic drugs (DMARDs) in patients with early rheumatoid arthritis (RA), according to a prospective study.
The investigators looked at 727 early RA patients (mean age 52.5 years; 72.6 percent female) enrolled in the Epidemiological Investigation of Rheumatoid Arthritis (EIRA) study and found that treatment was initiated with methotrexate (MTX) in majority (89.9 percent) of patients. More than half (56.9 percent) of the patients combined DMARDs with glucocorticoids.
On logistic regression analysis, the highest quartile of intakes of vitamin D and omega-3 FA (as measured using the food frequency questionnaire) were associated with good European League Against Rheumatism (EULAR) response after 3 months of DMARD treatment.
The adjusted odds ratio [aOR] for EULAR response was 1.61 (95 percent CI, 1.01 to 2.57) in patients with vitamin D intake of >6.97 vs ≤4.25 µg/day (p=0.048) and 1.68 (1.05 to 2.68; p=0.030) in patients with omega-3 FA intake of >0.84 vs ≤0.45 g/day (p=0.030). A similar pattern of results was observed in a subgroup of patients who were initially treated with MTX monotherapy at baseline.
On the other hand, no significant association was observed between dietary folate intake and EULAR response.
“These results, if confirmed, suggest that dietary interventions may be of interest in the management of RA, not only for reasons of optimising general health but also for achieving optimal results with antirheumatic medications,” researchers said.
Previous studies have reported an association between vitamin D deficiency and an increased risk of RA, with evidence suggesting that the deficiency can trigger autoimmune responses and therefore may provide an immunoregulatory effect. Meanwhile, omega-3 FA has been shown to have anti-inflammatory properties and reduce disease activity in RA. [Clin Rheumatol 2012;31:1733–9; Autoimmun Rev 2011;11:84–7; Arthritis Res Ther 2009;11:218]