N-3 polyunsaturated fatty acid diet therapy for patients with inflammatory bowel disease.

BACKGROUND: N-3 polyunsaturated fatty acids (PUFA) are considered important pharmaconutrients for modulating mucosal immunity and therapeutic responses in patients with inflammatory bowel disease (IBD). We investigated the influence of diet therapy involving the use of an "n-3 PUFA food exchange table" (n-3DP) on the fatty acid composition of the erythrocyte membranes of IBD patients and its remission-maintaining effects. METHODS: We analyzed the fatty acid composition of the erythrocyte membrane before and after n-3DP intervention in 20 initial-onset IBD patients who had not undergone any dietary intervention. We then analyzed it again and evaluated disease activity after 12-18 months intervention in 230 IBD patients (168 ulcerative colitis, 62 Crohn's disease; follow-up group) in whom n-3DP was introduced after remission had been achieved. The follow-up group was divided into remission and relapse groups. RESULTS: In the 20 initial-onset patients, the mean n-3/n-6 ratio significantly increased after intervention (0.41 ± 0.16 versus 0.70 ± 0.20; P < 0.001). In the follow-up group the ratio in the remission group (n = 145) was significantly higher than that in the relapse group (n = 85) (0.65 ± 0.28 versus 0.53 ± 0.18; P < 0.001). The ratio significantly decreased in those who suffered a relapse after the beginning of treatment (P < 0.01). CONCLUSIONS: N-3DP significantly increased the erythrocyte membrane n-3/n-6 ratio in IBD patients, and this ratio was significantly higher in the remission group, suggesting that n-3DP alters the fatty acid composition of the cell membrane and influences clinical activity in IBD patients.