Dietary interventions are increasingly recognized as critical in managing Crohn’s disease (CD). Among the most studied diets are the Crohn’s Disease Exclusion Diet (CDED), the Specific Carbohydrate Diet (SCD), and the Mediterranean Diet (MD). Each of these diets presents distinct mechanisms and clinical implications.
Crohn’s Disease Exclusion Diet (CDED)
Overview:
CDED is a structured, whole-food diet aimed at reducing exposure to dietary components that impair intestinal barrier function and promote dysbiosis. It is often paired with Partial Enteral Nutrition (PEN) in a phased approach.
Evidence:
A pivotal trial by Levine et al. demonstrated that CDED combined with PEN induced remission in 80% of pediatric CD patients by week 6, outperforming Exclusive Enteral Nutrition (EEN) in terms of tolerability and long-term adherence.1 Further studies have replicated these findings in adults.2
Strengths:
- Proven efficacy in inducing and maintaining remission
- Higher adherence rates compared to EEN
- Addresses both inflammation and microbiota imbalances
Limitations:
- Requires use of nutritional formulas
- Structured phases may be complex for patients to follow
Specific Carbohydrate Diet (SCD)
Overview:
SCD restricts complex carbohydrates, lactose, and processed foods, focusing on monosaccharides to limit bacterial fermentation and potential inflammation.
Evidence:
The DINE-CD trial, a randomized controlled study, found no significant difference in clinical remission rates between SCD and the Mediterranean diet in adults with mild to moderate CD.3 While some retrospective studies and anecdotal reports suggest symptom improvement, large-scale evidence remains inconsistent.4
Strengths:
- Emphasizes whole, unprocessed foods
- May improve symptoms in select individuals
Limitations:
- Highly restrictive and difficult to sustain
- Risk of nutritional deficiencies
- Lack of consistent clinical efficacy
Mediterranean Diet (MD)
Overview:
The Mediterranean diet emphasizes high consumption of fruits, vegetables, legumes, olive oil, whole grains, and moderate intake of fish and poultry, with minimal processed foods and red meat.
Evidence:
In the DINE-CD trial, the Mediterranean diet achieved similar remission rates to SCD, with higher patient satisfaction and sustainability.3 Its anti-inflammatory effects and cardiometabolic benefits are well documented across multiple populations.5
Strengths:
- Easier to adopt and maintain long term
- Beneficial beyond IBD (e.g., cardiovascular health)
- Less restrictive, nutritionally balanced
Limitations:
- May require customization for individual intolerances
- Slightly less targeted than CDED for gut-specific inflammation
Comparative Summary
Diet | Remission Induction | Restrictiveness | Long-Term Adherence | Additional Benefits |
---|---|---|---|---|
CDED | High (especially with PEN)1,2 | Moderate to High | Moderate | Gut-specific; targets dysbiosis |
SCD | Variable3,4 | High | Low | May help symptoms; low-quality evidence |
MD | Moderate3,5 | Low | High | Cardiovascular and anti-inflammatory benefits |
Conclusion
While all three diets can offer therapeutic value in Crohn’s disease, current evidence supports the CDED (with PEN) as the most effective for inducing remission, especially in children. The Mediterranean diet is highly sustainable, with broader health benefits and similar efficacy to SCD in symptom control. The SCD, although promising for some, lacks robust evidence and is challenging to maintain.
Individualization of dietary therapy, in collaboration with a gastroenterologist and registered dietitian, remains crucial.
References
- Levine A, Wine E, Assa A, et al. Crohn’s disease exclusion diet plus partial enteral nutrition induces sustained remission in a randomized controlled trial. Gastroenterology. 2019;157(2):440-450.e8. doi:10.1053/j.gastro.2019.04.021
- Yanai H, Shachar E, Levine A. The Crohn’s disease exclusion diet for induction and maintenance of remission in adults with mild-to-moderate Crohn’s disease. Therap Adv Gastroenterol. 2022;15:17562848221109464. doi:10.1177/17562848221109464
- Lewis JD, Chen EZ, Baldassano RN, et al. A randomized trial comparing the specific carbohydrate diet to a Mediterranean diet in adults with Crohn’s disease. Gastroenterology. 2021;161(3):837-852.e9. doi:10.1053/j.gastro.2021.05.047
- Suskind DL, Cohen SA, Brittnacher MJ, et al. Clinical and fecal microbial changes with diet therapy in active inflammatory bowel disease. J Clin Gastroenterol. 2018;52(2):155-163. doi:10.1097/MCG.0000000000000772
- Casas R, Sacanella E, Estruch R. The immune protective effect of the Mediterranean diet against chronic low-grade inflammatory diseases. Endocr Metab Immune Disord Drug Targets. 2014;14(4):245-254. doi:10.2174/1871530314666141021112855