People who live with inflammatory bowel disease (IBD) often have questions about what should and shouldn’t be included in a diet plan. There’s not one single diet for every person with IBD, which presents challenges for patients. Diet is difficult to study because there are so many variables. While more data and research on diet is clearly needed, there are some general guidelines that health care professionals can offer their patients. 

James Lewis, MD, MSCE, Associate Director, Inflammatory Bowel Disease Program and Professor of Medicine at the University of Pennsylvania in Philadelphia provided some background on diet and IBD at the 2019 Advances in Inflammatory Bowel Disease (AIBD) Meeting. The presentation that I attended, entitled “Diet, the Microbiome, and IBD: Doctor, what should I eat for my IBD?,” explored some of the current thinking about the interplay between diet and IBD.

Learning More About Diet and Risk of IBD

While there’s not much in the way of study for what people with IBD should eat to better manage their disease, there is research showing that diet may have an effect on the risk of developing IBD. A literature review of 19 studies showed some associations between risk of IBD and diet. Diets high in saturated fats, monounsaturated fatty acids, total polyunsaturated fatty acids (PUFAs), total omega-3 fatty acids, omega-6 fatty acids, mono- and disaccharides, and meat were associated with an increased risk of Crohn’s disease. An increased risk of ulcerative colitis was associated with diets high in total fats, total PUFAs, omega-6 fatty acids, and meat. Diets higher in fruit and dietary fiber and were associated with a lower risk of developing Crohn’s disease and diets high in vegetables were associated with a lower risk of ulcerative colitis.

Data from a large prospective study, the Nurses’ Health Study II, showed that those who ate a diet higher in fish and fiber during their teen years had a lower risk of developing Crohn’s disease as adults. No similar association could be made between ulcerative colitis and diet.
With that information in hand, the question then turns to whether or not a diet can help in the management of IBD.

Exclusion Diets and Crohn’s Disease

Dr Lewis also discussed the latest research in exclusion diets and Crohn’s disease. A dietary intervention called exclusive enteral nutrition (EEN) has been shown to be helpful for children and adolescents with Crohn’s disease. With EEN, only liquid nutrition is given and no foods are eaten. It may be used for 6 or 8 weeks (sometimes up to 12) to induce remission. Receiving all calories in formula drinks for that long is challenging, so new research is exploring the idea of adding a certain amount of specific foods (taken from the Crohn’s disease exclusion diet, or the CDED) along with the drinks. This method is called partial enteral nutrition (PEN). A 2019 study showed that PEN was also helpful in achieving remission from Crohn’s and it lasted longer than remission from EEN. In addition, researchers saw changes in the microbiome with PEN.

What People With IBD Report About Diet

Data from IBD Partners, which is a collaboration between patients and researchers, provided some insight into which foods people with IBD reported as improving or worsening their symptoms. Perhaps unsurprisingly, yogurt, rice, and bananas were the foods most often reported to improve symptoms. (The benefits of yogurt were mentioned during several other panels throughout the meeting, especially in regards to providing probiotics.) The list of foods that were associated with worsening symptoms included vegetables (both leafy and non-leafy), fruit, foods high in fiber, soda, milk, and red meat.

Diet Remains a Complicated Variable

All of this background information and study is getting researchers closer to understanding what patients should (or shouldn’t) eat. Dr Lewis stressed that healthcare providers need to assist patients in ensuring all nutritional needs are being met and in watching for any deficiencies. For some with Crohn’s disease, especially children and teens, EEN or PEN might be a valid treatment choice. On the whole, there is a broad recommendation that people with IBD follow  a Mediterranean-style diet that focuses on fresh ingredients. This includes increasing fruits and vegetables for those with Crohn’s disease and increasing omega 3 fatty acids (found in fish and certain foods such as flax and chia seeds, soybeans, and walnuts) for those with ulcerative colitis.

Dr Lewis finished his presentation with a focus on the future of diet and IBD. For mild to moderate IBD, diet may have a role as therapy, but providers must continue to carefully watch disease activity and provide nutritional support. Recommendations about diet should be evidence-based and come from the data provided by randomized controlled trials. For the future, focus should include personalized nutritional guidance and/or new medications that capitalize on what’s currently understood about how diet affects the course of IBD.

Sources:

• Ananthakrishnan AN, Khalili H, Song M, et al. High school diet and risk of Crohn’s disease and ulcerative colitis. Inflamm Bowel Dis. 2015;21:2311–2319. doi:10.1097/MIB.0000000000000501
• Cohen AB, Lee D, Long MD, et al. Dietary patterns and self-reported associations of diet with symptoms of inflammatory bowel disease. Dig Dis Sci. 2013;58:1322–1328. doi:10.1007/s10620-012-2373-3
• Hou JK, Abraham B, El-Serag H. Dietary intake and risk of developing inflammatory bowel disease: a systematic review of the literature. Am J Gastroenterol. 2011;106:563-573. doi: 10.1038/ajg.2011.44
• Levine A, Wine E, Assa A, et al. Crohn’s Disease Exclusion Diet Plus Partial Enteral Nutrition Induces Sustained Remission in a Randomized Controlled Trial. Gastroenterology. 2019;157:440-450.e8. doi: 10.1053/j.gastro.2019.04.021
• Lewis J. Diet, the Microbiome, and IBD: Doctor, what should I eat for my IBD? Presented at: 2019 AIBD Meeting; December 12-14, 2019; Orlando, FL.
• Malaty HM, Hou JK, Thirumurthi S. Epidemiology of inflammatory bowel disease among an indigent multi-ethnic population in the United States. Clin Exp Gastroenterol. 2010;3:165–170. doi:10.2147/CEG.S14586