High animal protein intake may worsen symptoms of inflammatory bowel disease (IBD) according to researchers from the Université Paris Sud.
Inflammatory bowel disease (IBD) is a general term for the chronic diseases—such as ulcerative colitis and Crohn’s disease—which cause inflammation of the colon. In IBD, the inner lining of the intestine becomes inflamed and ulcerated, often resulting in diarrhea. Incidence of IBD has increased dramatically since World War II and variations in risk among different populations suggest that environmental factors play a role.
In the French study, dietary intakes of nearly 70,000 women between the ages of 40 and 65 were compared to incidence of IBD over a ten-year period. On a per body weight basis, higher protein intake was linked to greater risk, but only when the protein came from meat or fish.
The findings concur with a small recently-published Japanese study which found that, of 16 patients with Crohn’s disease who adopted a semi-vegetarian diet which included soyfoods, 15 were able to remain in remission over the two year period of the study. Of the six patients who remained on an omnivore diet, only two remained in remission.
A number of compounds in animal foods can be metabolized by intestinal bacteria to form compounds that are damaging to the intestines, providing a biological explanation for the findings.
These findings suggest that limiting animal protein intake to no more than the RDA could reduce risk for IBD and possibly prevent relapse in patients with controlled IBD. Soyfoods can play a beneficial role by helping consumers meet protein needs on diets that limit animal proteins.
Jantchou P, Morois S, Clavel-Chapelon F, Boutron-Ruault MC, Carbonnel F. Animal Protein Intake and Risk of Inflammatory Bowel Disease: The E3N Prospective Study. Am J Gastroenterol 2010.
Chiba M, Abe T, Tsuda H, Sugawara T, Tsuda S, Tozawa H, Fujiwara K, Imai H. Lifestyle-related disease in Crohn’s disease: relapse prevention by a semi-vegetarian diet. World J Gastroenterol 2010;16:2484-95.