OBJECTIVE: To study the effect of supplementation with omega-3 fatty acids on disease variables and drug consumption in patients with ankylosing spondylitis (AS).

METHODS: Twenty-four patients were randomized to either a low-dose (1.95 g omega-3/day) or a high-dose (4.55 g omega-3/day) supplement. Disease activity, functional impairment, erythrocyte sedimentation rate (ESR), and drug consumption were assessed during visits at baseline and at weeks 7, 14, and 21.

RESULTS: Eighteen patients completed the study, nine patients from each group. The patients in the high-dose group exhibited a significant decrease in disease activity according to the Bath Ankylosing Disease Activity Index (BASDAI; p = 0.038), which was not seen in the low-dose group. Significant differences were not found on drug consumption or in functional capacity in either of the groups. No significant differences were found when comparing the results between the high- and low-dose groups.

CONCLUSION: Omega-3 fatty acids in adequate doses may have the capacity to decrease the disease activity of AS. However, larger and better controlled studies are needed before any further conclusions can be made on the extent of this capacity.