Margarine, red meat, cheese linked to increased risk for IBD
MedWire News: Individuals with signs and symptoms of inflammatory bowel disease (IBD) often change their diet before a confirmed diagnosis, say researchers who also found that a high consumption of margarine, red meat, and cheese increases the risk for ulcerative colitis and Crohn's disease.
These findings are of importance, as a causal relationship between diet and IBD is difficult to define due to the possibility that early symptoms may lead to a modification in dietary habits and the inability to recall diet patterns before onset of symptoms, say Giovanni Maconi (L Sacco University Hospital, Milan, Italy) and co-authors.
The researchers studied 83 patients newly diagnosed with IBD (41 ulcerative colitis, 42 Crohn's disease) and 160 healthy controls matched for gender and age, and comparable on measures of social status, years of education, body mass index, and smoking habits.
Using a validated questionnaire, participants recorded portions per week of 34 foods and beverages before onset of symptoms, duration of symptoms before diagnosis, and presence of specific symptoms and their impact on subjective changes in usual dietary habits.
In total, 32 (38.6%) patients reported a change in dietary habits due to the presence of symptoms before diagnosis of IBD. The main dietary changes comprised of reductions in fat and caloric intake (12 patients), reduction or cessation of fiber intake (18 patients), and reduction in milk or cheese intake (9 patients). Overall, these changes were not a result of specific symptoms, but in patients with Crohn's disease they were related to long duration of symptoms of at least 10 months.
To control for any confounding influence of symptom-induced changes in diet, the team assessed the link between food consumption and IBD risk in 51 patients who did not change dietary habits. A significantly increased risk for ulcerative colitis was found in patients reporting moderate consumption of meat (odds ratio [OR]=7.8) and high consumption of cheese (OR=3.7), based on tertiles of food consumption.
Conversely, a high consumption of fish and potatoes significantly reduced the risk for IBD, while a high intake of vegetables and tuna reduced the risk for Crohn's disease and a high intake of eggs attenuated the risk for ulcerative colitis.
The study also revealed an association between IBD and a refined diet high in pasta, sweets, red and processed meat, butter, and margarine.
Maconi et al conclude in the World Journal of Gastroenterology: "Our study is one of the few in the literature providing information on the changes in dietary habits before diagnosis in IBD patients, thus explaining the difficulties and uncertainties encountered in epidemiologic studies on diet and IBD,"
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By Ingrid Grasmo