Efficacy of IBD diets

Efficacy of IBD diets

September 21, 2021

Issue 18

Clinical Question

Can popular diets reduce IBD symptoms and inflammation?

Editor’s Bottom Line

While there remains keen and valid interest in dietary therapy for IBD, these data do not show the popular specific carbohydrate diet to offer any therapeutic advantage.


Lewis JD, Sandler RS, Brotherton C, et al. A Randomized Trial Comparing the Specific Carbohydrate Diet to a Mediterranean Diet in Adults with Crohn’s Disease. Gastroenterol. 2021;161(3):837–52.E9; https://doi.org/10.1053/j.gastro.2021.05.047


In the DINE-CD study, researchers at over 30 centers randomized 191 adults with mild-to-moderately active Crohn’s disease to follow either the Specific Carbohydrate Diet (SCD) or the Mediterranean diet for 12 weeks. The SCD excludes all grains, starches and processed foods and most sugars, while the Mediterranean diet emphasizes consumption of olive oil, fruits, vegetables, nuts, cereals, as well as moderate intake of fish, poultry and wine, in limited amounts. Participants in this study were given prepared meals and snacks for the first six weeks and asked to follow the diet independently thereafter.

Sixty-three percent of participants were women, most were white and 61% had nonstricturing and nonpenetrating disease. Additionally, 57% were receiving a biologic drug at baseline and 67% had previously received anti-tumor necrosis factor (TNF) treatment, including 11% who had received three or more anti-TNF agents.

Findings showed that 46.5% of those asked to adhere to the SCD and 43.5% of patients assigned to follow the Mediterranean diet experienced symptomatic remission at week six (p=0.77). There were similar improvements in both groups on the Crohn’s Disease Activity Index (CDAI), as well as in measures of quality of life, fatigue, sleep, pain and social isolation.

Results revealed that 34.8% and 30.8% of those with elevated fecal calprotectin (FC) levels at baseline who were assigned to follow the SCD or Mediterranean diet, respectively, experienced an FC response at six weeks, defined as FC <250 μg per gram, in addition to an FC reduction of >50% from baseline for those with baseline FC >250 μg/g (p=0.83). Moreover, 5.4% and 3.6% of those with elevated C-reactive protein (CRP) at baseline in the SCD and Mediterranean diet groups, respectively, experienced a CRP response at six weeks, defined as high-sensitivity (hs)-CRP <5 mg per liter at six weeks and a reduction of >50% in hs-CRP for those with hs-CRP >5 mg/L at baseline (p=0.68).


Study Design: Parallel group randomized trial

Funding: The Patient-Centered Research Outcomes Institute and the National Institutes of Health.

Allocation: Blinded randomization

Setting: Multicenter

Level of Evidence: 1b