Diet in IBD

Diet in IBD

Despite advances in medications available for Crohn’s Disease and Ulcerative Colitis, there is a still a proportion of patients who do not respond to these medications. This has allowed for better understanding of how the inflammatory bowel disease (IBD) develops. It is understood that genetics play a part in only 20% of the cases. More importantly, we now recognize the environment (particularly diet) and its interaction with the gut microbiota has a significant effect.

Role of diet in IBD

Drugs used to treat IBD, such as biologics suppress inflammation and immunity. However, there are still many other parts that need to be considered, such as the antigenic stimulation, gut permeability, and nutritional status. The good news is, diet has the potential to interact at all these different levels, more so than the medications.

Over time the prevalence of IBD is increasing across the world, as our diets have become more westernized. A paper published in 2017 by Luyi Xu et al showed how breastfeeding for at least 12 months can be protective against the development of both Crohn’s Disease and Ulcerative Colitis. This is the earliest evidence that highlights the role that diet must play a role in development of IBD but also its protective effect.

Animal studies have shown dietary constituents cause inflammation. The western diet is low in fiber and high in animal fat, which are both shown to cause these issues.

Exclusive Enteral Nutrition (EEN)

EEN to date provides the best evidence about the significance of diet in the management of IBD. Exclusive Enteral Nutrition (EEN) is now standard first line therapy for patients with paediatric Crohn’s Disease (if they can tolerate it), based on the ECCO-ESPHAGAN Guidelines from 20141. It has shown to:

  • Induce remissions in 60-80% of patients.
  • Induce mucosal healing2.
  • Improve C-Reactive Protein (CRP) and ESR levels (markers of inflammation).
  • Reduce the need for surgery3.

The biggest challenge with adults in using EEN is its poor tolerability and as a consequence around 50% discontinue4. It’s also for short term use only (i.e. 6-8 weeks) and therefore does not offer a longer-term solution.

Elimination diets

These diets work on the notion that remission is induced by what is NOT being consumed whilst being on EEN, but rather what has been removed from the diet and what is being allowed to eat. There have been several elimination diets that have been developed and studied, including:

  • autoimmune protocol diet,
  • IBD anti-inflammatory diet,
  • specific carbohydrate diet,
  • semi vegetarian diet, and
  • low FODMAP diet.

The one gaining a lot of buzz is the Crohn’s Disease Exclusion Diet (CDED). It’s based on real foods which is easier for patients to maintain. It has shown that it can help induce and maintain remission5,6,7.

CDED Pilot Study

A pilot study was conducted by researchers at the Royal Adelaide Hospital, to look at CDED with partial enteral nutrition in adults. 7 patients undertook the diet under expert dietetics supervision. All had active luminal Crohn’s Disease

The results showed that the diet was well tolerated; 6 out of 7 patients completed the full 12 weeks of prescribed diet. Only 1 patient required steroids throughout the 12 weeks.

All patients achieved clinical remission at 6 weeks, with a Harvey Bradshaw Index lower than 4.

There is emerging and promising evidence that use of CDED can form an important part of management of Crohn’s Disease. The hope is to develop structured pathways and guidelines for the routine use of dietary therapies in IBD, alongside current medications.

To speak to one of our gastroenterologists or dietitians about CDED, or other dietary therapies, make an appointment today.


  1. Ruemmele et al: Consensus guidelines of ECCO/ESPGHAN on the medical management of pediatric Crohn’s disease. J Crohns Colitis 2014; 8: 1179–1207
  2. Grover Z, Muir R, Lewindon P. Exclusive enteral nutrition induces early clinical, mucosal and transmural remission in paediatric Crohn’s disease. J Gastroenterol. 2014;49:638–645.
  3. Hu D, Ren J, Wang G, et al. Exclusive enteral nutritional therapy can relieve inflammatory bowel stricture in Crohn’s disease. J Clin Gastroenterol 2014;48:790–5.
  4. Ashton J.J et al. Clinical Nutrition. 2018. doi: 10.1016/j.clnu.2018.01.020.
  5. Sigall-Boneh R, et al. Inflamm Bowel Dis. 2014;20(8):1353-1360.
  6. Sigall-Boneh R, et al. J Crohns Colitis. 2017;11(10):1205-1212.
  7. Levine et al. Gastroenterology 2019;157:440–450


Contributed by Dr Abdul Shaikh