To compare the effectiveness of the Mediterranean diet (MD) and the Specific Carbohydrate Diet (SCD) in resolving symptoms among patients with Crohn’s disease
||Randomized controlled trial
||191 adults over age 18 with Crohn’s disease and mild to moderate symptoms
- Mediterranean Diet
- Specific Carbohydrate Diet
Primary: symptomatic remission, defined as a short Crohn’s Disease Activity Index score of less than 150 in the absence of initiation of or increase in any Crohn’s disease medications, at week 6
Secondary: symptomatic remission at week 12; clinical remission defined as a Crohn’s Disease Activity Index score of less than 150; health-related quality of life, pain, fatigue, sleep disturbance, and social isolation at 6 and 12 weeks
||6-week follow-up for primary outcome
This randomized controlled trial compared the effectiveness of two diets on achieving symptomatic and clinical remission and improving patient-reported outcomes among adults with Crohn’s disease. Both diets allow large amounts of fresh fruits and vegetables. The MD allows many types of foods but may limit amounts. For example, it includes large amounts of nuts, fish, whole grains, and olive oil but limits red meat and processed foods. The SCD lists foods that are and are not allowed. It allows fresh, unprocessed meats but not canned or processed foods, most dairy, or grains.
Researchers randomized patients to follow either the MD or SCD for 12 weeks. During the first six weeks, patients received weekly food deliveries of three prepared meals and two snacks for each day for their assigned diet. After six weeks, patients could choose to pay for weekly prepared meals or continue the diet on their own. The study website provided guidance for meal planning, and a dietician was available to answer questions.
The study included 191 adults with Crohn’s disease from across the United States. Of these, 91% were White, 4% were Black, 1% were Asian, and 4% reported other, more than one race, or did not report a race; 4% were Hispanic. The average age was 40, and 63% were female.
Patients completed surveys at the start of the study and again at 6 and 12 weeks. Patients reported their symptoms online daily. At weeks 3, 6, 9, and 12, patients reported their adherence to their assigned diet in the previous week.
Patients, doctors, and representatives from the Crohn’s & Colitis Foundation helped plan and conduct the study.
At six weeks, 64% of patients on the MD and 68% on the SCD reported full adherence to the diet. At 12 weeks, 42% of patients on MD and 40% on SCD reported full adherence to the diet.
The two diets did not differ significantly in any outcomes at 6 or 12 weeks. At six weeks, 44% of patients on the MD and 47% on the SCD achieved symptomatic remission, and 48% on the MD and 49% on the SCD achieved clinical remission. With both diets, patients reported fewer symptoms, higher health-related quality of life, and less pain, fatigue, sleep disturbance, and social isolation (all p<0.03) at six weeks.
Providing prepared meals during the first six weeks may have optimized adherence and overestimated the effectiveness of these diets in general practice. Most patients in the study were White. Results may differ for people from other racial backgrounds.
Conclusions and Relevance
In this study, regardless of diet, more than 40% of patients with Crohn’s disease had symptomatic and clinical remission after six weeks, with no significant differences between the diets.
Future Research Needs
Future research could compare the MD and SCD with other diets recommended in the treatment of Crohn’s disease.
|How this project fits under PCORI’s Research Priorities
IBD Partners formerly was a Network Partner in PCORnet®, the National Patient-Centered Clinical Research Network. PCORnet® has been developed with funding from the Patient-Centered Outcomes Research Institute (PCORI).