One of the most frequent questions that patients with inflammatory bowel disease (IBD) ask is: what should I eat?
It is clear that in addition to genetic factors, certain environmental factors, including diet, may trigger the excessive immune activity that leads to intestinal inflammation in IBD, which includes both Crohn’s disease and ulcerative colitis (UC). However, the limited number and high variability of studies have made it difficult to confidently advise patients regarding which specific foods might be harmful and which are safe or may actually provide a protective benefit.
New IBD dietary guidelines
To help patients and providers navigate these nutritional questions, the International Organization of IBD (IOIBD) recently reviewed the best current evidence to develop expert recommendations regarding dietary measures that might help to control and prevent relapse of IBD. In particular, the group focused on the dietary components and additives that they felt were the most important to consider because they comprise a large proportion of the diets that IBD patients may follow.
The IOIBD guidelines include the following recommendations:
Food
If you have Crohn’s disease
If you have ulcerative colitis
Fruits
increase intake
insufficient evidence
Vegetables
increase intake
insufficient evidence
Red/processed meat
insufficient evidence
decrease intake
Unpasteurized dairy products
best to avoid
best to avoid
Dietary fat
decrease intake of saturated fats and avoid trans fats
decrease consumption of myristic acid (palm, coconut, dairy fat), avoid trans fats, and increase intake of omega-3 (from marine fish but not dietary supplements)
Food additives
decrease intake of maltodextrin-containing foods
decrease intake of maltodextrin-containing foods
Thickeners
decrease intake of carboxymethylcellulose
decrease intake of carboxymethylcellulose
Carrageenan (a thickener extracted from seaweed)
decrease intake
decrease intake
Titanium dioxide (a food colorant and preservative)
decrease intake
decrease intake
Sulfites (flavor enhancer and preservative)
decrease intake
decrease intake
The group also identified areas where there was insufficient evidence to come to a conclusion, highlighting the critical need for further studies. Foods for which there was insufficient evidence to generate a recommendation for both UC and Crohn’s disease included refined sugars and carbohydrates, wheat/gluten, poultry, pasteurized dairy products, and alcoholic beverages.
How would observing these guidelines help?
The recommendations were developed with the aim of reducing symptoms and inflammation. The ways in which altering the intake of particular foods may trigger or reduce inflammation are quite diverse, and the mechanisms are better understood for certain foods than others.
For example, fruits and vegetables are generally higher in fiber, which is fermented by bacterial enzymes within the colon. This fermentation produces short-chain fatty
