Maurice G. V. M. Russel

Diet as a risk factor for the development of ulcerative colitis

OBJECTIVE:Dietary factors have been considered as a possible risk factor for ulcerative colitis (UC). However, available data are inconsistent. The aim of the present study was to evaluate the etiological role of dietary factors in the development of UC.METHODS:Recently diagnosed (<6 Months) UC patients (n = 43) and age- and gender-matched population controls (n = 43) were studied in a case-control design. The cross-check dietary history method was used to assess dietary intake of 5 yr before the study. Adipose tissue fatty acid composition was used as a biomarker of long-term fat intake. Conditional logistic regression-derived odds ratios (OR), and 95% confidence intervals (CI) were used for statistical analysis. Dietary intake ORs were adjusted for energy intake.RESULTS:High intakes of monounsaturated fat (OR: 33.9 [95% CI 2.6–443.1]), polyunsaturated fat (OR: 5.1 [95% CI 1.0–26.7]), and vitamin B6 (OR: 6.9 [95% CI 1.6–30.7]) were associated with an increased risk to develop UC. No other significant associations were found with UC risk.CONCLUSIONS:High intakes of mono- and polyunsaturated fat and vitamin B6 may enhance the risk of developing UC. Whether this observation is a true risk factor in the development of UC or rather a reflection of a certain dietary lifestyle needs to be investigated.

Inflammatory bowel disease: is there any relation between smoking status and disease presentation? European Collaborative IBD Study Group.

Smoking is associated with Crohns disease and nonsmoking with ulcerative colitis. The aim of this study was to compare the clinical features at diagnosis and during the first year of follow-up in smokers and nonsmokers with inflammatory bowel disease (IBD). In 19 centers across Europe, a prospective study was performed of 457 newly diagnosed patients with Crohns disease and 930 with ulcerative colitis. The characteristics of the disease were recorded by the treating physician by using a standard protocol at the time of diagnosis. Treatment characteristics were assessed after 1 year of follow-up. Weight loss occurred significantly more often in smoking patients with Crohns disease, as well as in smokers with ulcerative colitis (p < 0.02), and diarrhea was more frequent in smoking patients with Crohns disease compared with non-smoking individuals (p < 0.01). Patients with Crohns disease who smoke were less likely to have colonic involvement (p < 0.01) and were more often prescribed immunosuppressive medication (p < 0.02). The study suggests that (a) smoking protects the colon from inflammation and (b) is associated with more active disease in Crohns disease. The association between weight loss and smoking in both diseases is probably due to a general effect of smoking. The reported relation between smoking and the course of Crohns disease is a strong argument for encouraging patients to give up smoking.

Nutritional supplementation with N-3 fatty acids and antioxidants in patients with Crohn's disease in remission: effects on antioxidant status and fatty acid profile.

Summary: In patients with Crohns disease (CD), malnutrition is frequently observed and is generally accepted to be an important issue. The aim of this study was to investigate the effects of 3 months of supplementation with a liquid formula containing either antioxidants (AO) or n‐3 fatty acids plus AO on the antioxidant status and fatty acid profile of plasma phospholipids and adipose tissue, respectively, in patients with long‐standing CD currently in remission. In a randomized, double‐blind placebo‐controlled study, CD patients received either placebo, AO, or n‐3 fatty acids plus AO for 3 months in addition to their regular diet. In all, 25/37 CD patients completed the study. AO status was assessed by blood biochemical parameters. A statistical per‐protocol analysis was performed. Serum concentrations of selenium, vitamin C, and vitamin E, the activity of superoxide dismutase and total antioxidant status were significantly (p < 0.05) increased after AO supplementation. Furthermore, compared with controls, serum concentrations of &bgr;‐carotene, selenium, and vitamin C and the activity of glutathione peroxidase (GPx) were significantly (p < 0.05) lower before supplemention; however, after AO supplementation these levels were not significantly different from controls (except for GPx). N‐3 fatty acids plus AO supplementation significantly (p < 0.05) decreased the proportion of arachidonic acid, and increased the proportion of eicosapentanoic acid and docosahexanoic acid in both plasma phospholipids and adipose tissue. Supplementation with antioxidants improved antioxidant status in patients with CD in remission. In addition, supplementation with n‐3 fatty acids plus antioxidants significantly changed the eicosanoid precursor profile, which may lead to the production of eicosanoids with attenuated proinflammatory activity. This study indicates that an immunomodulating formula containing n‐3 fatty acids and/or AO may have the potential to play a role in the treatment of CD.