A Summary of Revolution in diet therapy for inflammatory bowel disease - Melton - 2024 - JGH Open - Wiley Online Library
By Peter Park, 4th year medical student, Plano Texas
Disclaimer: This piece is not intended to serve as medical advice, but as a reflection on strategies for patient advocacy. Always talk to your GI provider before making any changes to your diet, medication regimen, or any other aspects of your health care.
This is a review article that compiles several studies which center around how diet interplays with Crohn's disease and colitis. Articles are subcategorized by well known factors that contribute to inflammation including meat, dairy, additives, and fiber. Articles and studies are also graded on academic rigor with the gold standard being a randomized control trial and lower quality studies being observational data.
Exclusive Enteral Nutrition (EEN)
First, the article talks about EEN. What is EEN? EEN stands for Exclusive Enteral Nutrition, which means nutritional resources come from a liquid formula for 6-8 weeks (gross). EEN has been shown to achieve clinical remission similar to corticosteroids in pediatric populations. Adult populations seem to follow a similar trend.
Compared to steroids, using a EEN liquid formula based diet is way better to remove the potential harmful side effects of steroids. More specific data shows that factors such as male sex, younger age, milder disease, and certain microbiome profiles respond better to EEN. One criticism can be the healthy user bias where study participants are naturally going to be healthier people and that the person who can tolerate EEN for 6-8 weeks may just be a more self-disciplined person with less financial or social barriers, and overall healthier person.
Partial Enteral Nutrition (PEN)
Let’s be real. Would you sign up for a smoothie-only diet for 6-8 weeks? Authors looked into other diet options such as PEN or Partial Enteral Nutrition where only a portion of food intake is liquid formula and the rest is unrestricted food intake. However, studies have not been promising in PEN’s ability to reduce inflammatory markers such as fecal calprotectin or CRP. Whether that's because of poor ability to stay on that diet or whether that's because of the diet itself is hard to say.
Crohn’s Disease Exclusion Diet (CDED)
Crohn’s Disease Exclusion Diet (CDED) uses 50% PEN and permits only certain foods in three phases:
Phase 1 - Chicken breast, fish, lean meats, olive oil, onion, potatoes, rice, tomatoes
Phase 2 - certain legumes, fruits (blueberries, kiwis, and peaches), vegetables (broccoli, cauliflower, sweet potato, and zucchini), oats, whole-grain bread and pasta
Phase 3 - can introduce foods such as alcohol, coffee, dairy, grains, and seafood
Foods to avoid in ALL phases - Process meat, artificial sweeteners, seeds, emulsifiers, and preservatives
CDED has been shown to reduce inflammatory markers but has yet to be validated in a larger scale study.
Find more information about the Crohn’s Disease Exclusion Diet on the Nutrition Therapy for IBD website.
Diets for Ulcerative Colitis
There's exciting new evidence in ulcerative colitis that indicates that high levels of Hydrogen sulfide (H2S) can increase disruption of the microbiome and cause injury to the colon. Fecal transplant has also been shown to be more impressive and impactful in reducing inflammatory markers when paired with a plant based and low protein based diet. The Mediterranean diet has also shown to improve inflammatory markers but it still seems unsure whether the Mediterranean diet alone is causing this or whether it's the removal of the standard American diet which is known to be high in fats and protein.
I personally want to focus not on any specific diet but the overarching data that seems to indicate that avoiding processed foods, especially processed meats, can help to reduce inflammatory markers. Whether that reduces symptoms from a subjective patient point of view is a little harder to capture in the data. So far, the evidence is clear: There is no evidence that IBD can be treated with diet alone.
Our disease as IBD patients is still a medical disease that requires specific medications and Hopefully we can continue to see more diet and nutritional studies as we all have personal common-sense-knowledge that diet does impact our flares.
One of the best ways to personalize your own flares is to capture a food journal where you can document certain food triggers that occur with flares. This can be really useful in bringing to your gastroenterologist or other specialist, in order to develop a diet plan that works for you. There’s real hope in using food as part of your treatment plan, and with the right approach, it could help you feel more in control of your IBD.
Featured photo by Dana Tentis from Pexels.