Objective: Data concerning the anti-inflammatory effect of dietary n-3 polyunsaturated fatty acids (PUFAs) in patients with ulcerative colitis (UC) are inconsistent. Salmon fillet contains n-3 PUFAs and bioactive peptides that may improve its effects compared to fish oil alone. We assessed the efficacy of a salmon-rich diet in patients with mild ulcerative colitis.
Methods: An 8-week intervention pilot study was designed to assess the effects of 600 grams Atlantic salmon consumption weekly in 12 UC patients. Simple clinical colitis activity index (SCCAI), a dietary questionnaire, sigmoidoscopy, selected serum inflammatory markers, fecal calprotectin, and plasma and rectal biopsy fatty acid profiles were assessed before and after intervention.
Results: The levels of C20:4n-6 arachidonic acid in biopsies after dietary intervention were correlated with histology and endoscopy scores. The concentrations of n-3 PUFAs, C20:5n-3 eicosapentaenoic acid, C22:6n-3 docosahexaenoic acid, and the n-3/n-6 ratio increased in plasma and rectal biopsies. The anti-inflammatory fatty acid index (AIFAI) increased both in biopsies and plasma accompanied with a significantly reduced SCCAI.
Conclusion: Based on evidence of SCCAI and AIFAI and a tendency of decreased levels of CRP and homocysteine, intake of Atlantic salmon may have beneficial effects on disease activity in patients with mild ulcerative colitis.