January 29, 2015
Gastroenterology
TAKE-HOME MESSAGE
- The authors review diet in the management of inflammatory bowel disease (IBD). Studies regarding the effect of food on IBD are discussed.
- Overall, authors found that components of some whole foods can cause IBD symptoms, whereas some nutrients may decrease inflammation of the intestines. Specific diets may improve the success of inducing and maintaining remission of IBD.
Nutrition Therapy for IBD
Written by David Rakel MD, FAAFP
This evidence-based review by Lee and colleagues1 explores how nutrition can be used to treat and prevent relapses of inflammatory bowel disease. Here are the highlights.
There has been ample research showing that nutrition can reduce inflammation, reducing the risk for cardiovascular events.2 It is thus not surprising that a Mediterranean-like diet that is low in meat, fat, and omega-6 fatty acids (cooking oils and red meat) is beneficial for patients with inflammatory bowel disease (IBD). I like to keep it simple for my patients, letting them know what the Mediterranean, anti-inflammatory diet doesn’t have. It does not have red meat, dairy and sugar, three inflammatory triggers when consumed in excess.
The nutrients that appeared to be protective in IBD include (no big surprises here) vegetables, fruit, fiber, and omega-3 fatty acids. Omega-3 fatty acids (cold-water fish, nuts, and avocados) are well known to have anti-inflammatory effects, but fiber works by interacting with the microbiome to create short-chain fatty acids (eg, butyrate), which help repair the intestinal lining and down-regulate inflammation. Other “super food/drinks” that are helpful for IBD include green tea, curcumin, and polyphenols (resveratrol). There is evidence that vitamin D also has benefit.
Although difficult to use long-term, exclusive enteral nutrition (EEN) has been found to induce remission when used for an IBD flare. Interestingly, the composition of the formula (high fat or low fat) does not appear to matter. The thought is that the mechanical requirements to digest whole foods may inhibit the healing effects for IBD.
Our goal in primary care should be to encourage a whole food, anti-inflammatory, Mediterranean diet so that we do not have to use as many rescue therapies such as EEN and steroids, but it is nice to see that EEN can be as effective as steroids for treating IBD flares.
References
- Lee D, Albenberg L, Compher C, et al. Diet in the pathogenesis and treatment of inflammatory bowel diseases [published online ahead of print January 15, 2015]. Gastroenterology. doi: 10.1053/j.gastro.2015.01.007. http://www.sciencedirect.com/science/article/pii/S0016508515000694
- Estruch R, Ros E, Salas-Salvado J, et al. Primary prevention of cardiovascular disease with a Mediterranean diet. N Engl J Med. 2013;368:1279-1290. http://www.nejm.org/doi/full/10.1056/NEJMoa1200303
Abstract
Some of the most common symptoms of the inflammatory bowel diseases (IBD, which include ulcerative colitis and Crohn’s disease) are abdominal pain, diarrhea, and weight loss. It is therefore not surprising that clinicians and patients have wondered whether dietary patterns influence the onset or course of IBD. The question of what to eat is among the most commonly asked by patients and among the most difficult to answer by clinicians. There are therefore substantial variations in dietary behaviors of patients and recommendations for them, although clinicians do not routinely endorse specific diets for patients with IBD. Dietary clinical trials have been limited by their inability to include a placebo control, contamination of study groups, and inclusion of patients receiving medical therapies. Further challenges include accuracy of information on dietary intake, complex interactions between foods consumed, and differences in food metabolism among individuals. We review the roles of diet in the etiology and management of IBD, based on plausible mechanisms and clinical evidence. Researchers have learned much about the effects of diet on the mucosal immune system, epithelial function, and the intestinal microbiome; these findings could have significant practical implications. Controlled studies of patients receiving enteral nutrition and observations made from patients on exclusion diets have shown that components of whole foods can have deleterious effects for patients with IBD. Additionally, studies in animal models suggested that certain nutrients can reduce intestinal inflammation. In the future, engineered diets that restrict deleterious components but supplement beneficial nutrients could be used to modify the luminal intestinal environment of patients with IBD-these might be used alone or in combination with immunosuppressive agents, or as salvage therapy for patients who do not respond or lose responsiveness to medical therapies. Stricter diets might be required to induce remission, whereas more sustainable exclusion diets could be used to maintain long-term remission.