The therapeutic effect of enteral nutrition in Crohn's disease (CD) and the epidemiological associations between diet and inflammatory bowel disease (IBD) implicate diet in IBD causation.
There is little evidence, however, to support specific dietary changes and patients often receive contradictory advice.
Professor Rhodes and colleagues from the United Kingdom reviewed the literature on the impacts of diet on IBD causation and activity to produce guidance based on ‘best available evidence’.
The researchers reviewed Medline, Embase and Cochrane databases from 1975 to 2012 using MeSH headings ‘crohn's disease’ ‘ulcerative colitis’ ‘enteral’ ‘diet’ ‘nutrition’ ‘fatty acid’ and ‘food additives’.
|High intakes of meat and margarine correlate with increased ulcerative colitis|
|Alimentary Pharmacology & Therapeutics|
Enteral nutrition with a formula-defined feed is effective treatment for Crohn's disease, but approximately 50% of patients relapse within 6 months of return to normal diet.
There is no direct evidence of benefit from any other specific dietary modification in Crohn's disease, but indirect evidence supports recommendation of a low intake of animal fat, insoluble fibre and processed fatty foods containing emulsifiers.
The research team found that foods tolerated in sustained remission may not be tolerated following relapse.
The team identified some evidence that supports vitamin D supplementation.
In ulcerative colitis, evidence is weaker, but high intakes of meat and margarine correlate with increased ulcerative colitis incidence and high meat intake also correlates with increased likelihood of relapse.
Professor Rhodes' team concludes, "There is little evidence from interventional studies to support specific dietary recommendations."
"Nevertheless, people with IBD deserve advice based on ‘best available evidence’ rather than no advice at all, although dietary intake should not be inappropriately restrictive."
"Further interventional studies of dietary manipulation are urgently required."