Food-additive emulsifiers and the low emulsifier diet in Crohn's disease

Student thesis: Doctoral ThesisDoctor of Philosophy


Crohn’s disease is an inflammatory bowel disease characterised by chronic relapsing gastrointestinal inflammation. Recent evidence implicates food-additive emulsifiers in Crohn’s disease pathogenesis, though this is limited to in vitro and animal studies, where emulsifiers modify microbiome and increase intestinal inflammation. The aim of this thesis was to explore the role of emulsifiers in Crohn’s disease.

Characterising the prevalence of emulsifiers in the food supply is important, and a database of 8296 ultra-processed foods in the UK food supply was systematically compiled, demonstrating that 55.2% of foods contained emulsifiers (Chapter 2).

The therapeutic potential of a low emulsifier diet in the treatment of Crohn’s disease has not been investigated. Therefore, a novel a low emulsifier dietary intervention was developed (Chapter 3). Prior to investigating this in a full clinical trial, a feasibility study of the low emulsifier diet for 14-days was conducted in 20 patients with Crohn’s disease (Chapter 3). Although 90% of participants reported the diet was difficult to follow, 95% achieved dietary adherence and median reduction in frequency of emulsifier intake was -97.7% (p<0.001). The diet was nutritionally adequate with no negative impacts on food-related quality of life (Chapter 4).

Emulsifier-containing and emulsifier-free snacks were designed for use in a double-blind, re-supplementation randomised controlled trial (RCT) investigating the impact of an 8-week low emulsifier diet on Crohn’s disease activity (Chapter 5). Recruitment to the trial was hampered by the COVID-19 pandemic and so was underpowered (n=10). Interim analysis indicates a 40.0% response and remission rate across all patients based on the Crohn’s Disease Activity Index (Chapter 6). High adherence to the dietary restrictions for 8 weeks (median reduction in frequency of emulsifier intake -86.7%, p=0.027), plus the high snack adherence (80.0%) means that when fully powered, this robustly designed re-supplementation RCT will determine whether there is a significant clinical benefit to following a low emulsifier diet to reduce Crohn’s disease activity.

This thesis has established that emulsifiers are ubiquitous in the food supply and are frequently consumed in the habitual diets of people with Crohn’s disease. However, dietary exclusion of emulsifiers is feasible, but whether this results in clinical improvements in active Crohn’s disease requires ongoing investigation.
Date of Award1 Jan 2022
Original languageEnglish
Awarding Institution
  • King's College London
SupervisorKevin Whelan (Supervisor) & Megan Rossi (Supervisor)

Cite this