Randomized controlled trial of a natural whole food diet versus habitual diet for Crohn's disease: Is diet quality the key?

Abstract

Background & aims: Diets can help induce remission in patients with Crohn's disease (CD). However, given inconsistent recommendations across purportedly beneficial anti-inflammatory diets and prior studies highlighting benefits of plant-based diet patterns, we hypothesized that the benefit of diet therapy stems from the overall "healthfulness" of diet patterns.

Methods: In a randomized controlled trial, adults with mild-to-moderate CD were assigned to receive guidance on a natural whole food diet that comprised principles of a healthful diet versus continuation of one's habitual diet. Primary outcomes included clinical remission and change in calprotectin in weeks 4 and 8. Secondary outcomes included nutritional parameters (nutrient and energy intake, body composition, metabolic rate) and adverse events. Healthy Eating Index (HEI) served as a surrogate of diet quality and adherence.

Results: Twenty-eight participants with active CD were randomized. In intention-to-treat analysis, whole food diet led to overall greater clinical remission (odds ratio [OR] 1.41; 95 % CI 1.03-1.93; P = 0.03) and similar change in calprotectin. In per protocol analysis, adherence to a healthful diet was associated with clinical remission (OR 1.18; 95 % CI 1.02-1.38; P = 0.03) and change in calprotectin (-234; 95 % CI -465 to -3; P = 0.047). There was no increased risk of nutritional deficiency or reported adverse events.

Conclusion: Following a natural whole food diet based on principles of a "healthful" diet was safe and effective for inducing clinical remission and reducing fecal calprotectin concentrations in mild-to-moderate CD. Further investigation is needed to confirm these findings and to identify mechanisms to improve adherence to healthy anti-inflammatory diets.

Gov registration: NCT04431700.

Keywords: Calprotectin; Diet; Inflammatory bowel disease; Nutrition; Remission; Symptoms.