Very long chain n-3 polyunsaturated fatty acids have modulating effects on inflammatory mechanisms. Seal and fish oils are rich in n-3 polyunsaturated fatty acids, and possibly therefore high doses of nasoduodenally administered seal oil rapidly relieved inflammatory bowel disease (IBD)-associated joint pain in two recent studies. In the present study, we compared the effects of short-term oral administration of seal oil and cod liver oil on IBD-related joint pain, leucotriene B(4) level, serum fatty acid profile and IBD activity.

Thirty-eight patients with IBD-related joint pain were included in the study; 21 had Crohn's disease and 17 ulcerative colitis. Ten milliters of seal oil (n=18) or cod liver oil (n=20) was self-administered orally 3 times a day for 14 days before meals in a double-blind setting.

There were no significant differences between the two intervention groups or between Crohn's disease and ulcerative colitis patients. There was a tendency toward improvement in several joint pain parameters after both seal oil and cod liver oil administration. Further, plasma leucotriene B(4) concentration, serum Sigma n-6 to Sigma n-3, and arachidonic acid (20:4n-6) to eicosapentaenoic acid (20:5n-3) ratios were similarly reduced after administration of seal oil and cod liver oil.

No significant differences in the two treatment groups were seen; in both groups, the changes in several joint pain parameters, leucotriene B(4) level of plasma, and serum fatty acid profile were putatively favourable.