People with Crohn’s Disease and Ulcerative Colitis have tricky relationships with food. The wrong food – and sometimes any food – can cause pain and misery, but many of us hope the right diet will help us live with our condition with minimal medications or surgery.
A recent review article in the journal Nutrition in Clinical Practice* looked at the evidence for various diets and foods for inflammatory bowel disease. They noted that while 90% of patients with IBD think diet is important, only 20% were given adequate dietary advice.
The authors looked at a number of studies on the following foods and diets:
- Fats: while dietary fat intake correlates with increased rates of Crohn’s and UC, the authors found no studies that show decreasing dietary fat helps manage the diseases. There were also no studies that showed good evidence for omega-3 (fish oil) in helping manage IBD.
- Fiber: while many IBD patients avoid fibrous foods (like veggies), the only study to test a low-fiber diet found no difference in Crohn’s (UC wasn’t studied). On the other hand, there is better – but still weak – evidence that a high fiber diet might help both CD and UC. A very small study in Japan showed promise for a vegetarian diet, but more research is needed.
- Carbohydrates: Evidence for the popular ‘specific carbohydrate diet’ is very limited; there are small studies showing positive results, but there are no clinical trials of the diet. Clinical trials find no evidence that lactose-free diets help with IBD, except for patients who are also lactose intolerant. There is also no solid evidence for the efficacy of the low-FODMAP diet, the Paleo diet, or a gluten-free diet.
- Enteral nutrition: studies show that enteral nutrition as either a supplement to a regular diet (EN) or as the only source of nutrition can help patients with Crohn’s disease. Some studies have shown EN to be comparable to steroids in helping patients achieve remission, although on balance the evidence shows steroids to be more effective.
- Pareneteral nutrition: the authors found that evidence for total parenteral nutrition and ‘bowel rest’ is weak, despite the common use of the practice. However, PN can help patients as a supplement for those who can’t do EN.
The authors did not cover many popular supplements for IBD, only because they have not been studied scientifically. Because of the mixed or weak evidence for many popular diets for IBD, the authors conclude the article with this advice:
We cannot recommend a specific oral diet to treat IBD, other than to limit foods that are felt to aggravate symptoms.
This agrees with Crohnology results: the top 5 most effective ‘treatments’ according to member input are “No Beer”, “No Spicy Foods”, “No Refined Sugars”, “No Dairy”, and “No Wine”. On the other hand, Crohnology members also rate the specific carbohydrate diet and gluten-free diet as top treatments. Clearly, there is room for more research on diets and inflammatory bowel disease.
*The article is Shah et al., “Oral Diets and Nutrition Support for Inflammatory Bowel Disease: What Is the Evidence?” Nutrition in Clinical Practice June 17, 2015. Free Abstract. The full text was provided by a friend of the blog.