DINE-CDCD · Diet
A Randomized Trial Comparing the Specific Carbohydrate Diet to a Mediterranean Diet in Adults With Crohn's Disease
Lewis JD, et al.
Gastroenterology 2021 · PMID 34052278 (PubMed, opens in a new tab) · doi 10.1053/j.gastro.2021.05.047 (full paper, opens in a new tab)
| Endpoint | Specific Carbohydrate | Mediterranean | Difference |
|---|---|---|---|
| Symptomatic remission, Week 6 (primary endpoint) | 46.5% | 43.5% | P=0.77; Specific Carbohydrate Diet not superior |
| Calprotectin response, Week 6 · baseline above 250 µg/g | 34.8% (8/23) | 30.8% (4/13) | P=0.83 |
| CRP response, Week 6 · baseline hs-CRP above 5 mg/L | 5.4% (2/37) | 3.6% (1/28) | P=0.68 |
Few patients had objective inflammation at baseline, so this is mainly a trial of symptoms.
Source: Lewis 2021, abstract (191 patients in the efficacy analysis).
Structured abstract
BackgroundPatients with Crohn's disease often ask about restrictive diets; whether the Specific Carbohydrate Diet works better than an easier, healthy Mediterranean diet had not been tested head to head.
MethodsMulticentre randomised trial (1:1), 12 weeks; prepared meals and snacks supplied for the first 6 weeks, then self-directed. 194 patients. Primary endpoint: Symptomatic remission at week 6.
ResultsPrimary result. 46.5% with the Specific Carbohydrate Diet vs 43.5% with the Mediterranean diet; P=0.77 (Specific Carbohydrate Diet not superior).
Take-homeIn adults with mild-to-moderate Crohn's symptoms, the restrictive Specific Carbohydrate Diet was no better than a Mediterranean diet, so the easier, healthier Mediterranean diet is the reasonable default.
| Patients | 194 |
|---|---|
| Population | Adults with Crohn's disease and mild-to-moderate symptoms. 191 included in the efficacy analyses. |
| Comparison | Specific Carbohydrate Diet vs Mediterranean diet |
| Published | Lewis JD, et al. Gastroenterology 2021;161:837–52.e9. |
Key points
- Faecal calprotectin response (below 250 µg/g and a fall of more than 50% in those starting above 250): 34.8% (8/23) vs 30.8% (4/13); P=0.83.
- CRP response (high-sensitivity CRP below 5 mg/L and a fall of more than 50% in those starting above 5): 5.4% (2/37) vs 3.6% (1/28); P=0.68.
- CRP responses were uncommon in both arms.
- The authors concluded that the Mediterranean diet may be preferred for most patients, given its ease and wider health benefits.
Limitations
- Symptom-based primary endpoint; few patients had raised calprotectin or CRP, so effects on inflammation could not be judged.
- No control arm on a usual diet, and participants were not blinded.
- Mild-to-moderate symptoms only; not a substitute for effective drug therapy in active inflammatory disease.
Commentary
DINE-CD answers a question patients ask often: is a strict exclusion diet worth it? Neither diet clearly reduced inflammation, and the Specific Carbohydrate Diet offered no advantage over a Mediterranean diet that is easier to follow and good for cardiovascular health.
How to use it: recommend a Mediterranean-style diet as a sensible base for adults with Crohn’s disease, with a dietitian’s help when intake is restricted or a stricture is present. Do not use diet alone to treat objectively active disease. Exclusion diets with partial enteral nutrition have stronger evidence for inducing remission, mainly in children (see CDED plus PEN).
Journal club
Design
Multicentre randomised trial (1:1), 12 weeks; prepared meals and snacks supplied for the first 6 weeks, then self-directed. 194 patients.
Primary result. 46.5% with the Specific Carbohydrate Diet vs 43.5% with the Mediterranean diet; P=0.77 (Specific Carbohydrate Diet not superior).
Validity and applicability
- Symptom-based primary endpoint; few patients had raised calprotectin or CRP, so effects on inflammation could not be judged.
- No control arm on a usual diet, and participants were not blinded.
- Mild-to-moderate symptoms only; not a substitute for effective drug therapy in active inflammatory disease.
Where it sits now
In adults with mild-to-moderate Crohn's symptoms, the restrictive Specific Carbohydrate Diet was no better than a Mediterranean diet, so the easier, healthier Mediterranean diet is the reasonable default.
- CDED plus PEN vs EEN (2019): In children with mild to moderate Crohn's disease, CDED plus partial enteral nutrition is better tolerated than exclusive enteral nutrition and gives more sustained remission at 12 weeks.
Questions for discussion
- There was no usual-diet control arm. What can a comparison of two diets tell you, and what can it not?
- Few patients had raised calprotectin or CRP. Was this a trial of inflammation or of symptoms?
- How would you advise a patient who wants to try a restrictive diet instead of starting a biologic?