NHD CPD eArticle Volume 9.03 - 7th March 2019
THE LOW-FODMAP DIET FOR CROHN’S DISEASE Priya Tew Freelance Dietitian and Specialist in Eating Disorders Priya runs Dietitian UK, a freelance dietetic service that specialises in social media and media work, consultancy for food companies, eating disorder support, IBS and chronic fatigue. She works with NHS services, The Priory Hospital Group and private clinics, as well as providing Skype support to clients nationwide.
This article will look into current research in the area of the low-FODMAP diet and its effect on functional gut symptoms. Crohn’s disease is an autoimmune condition that can affect anywhere along the gastrointestinal tract, with ulceration and an unpredictable relapsing remitting course. Symptoms commonly include abdominal pain, bloody diarrhoea, fatigue, loss of appetite and weight loss. FODMAPs are short-chain carbohydrates that are poorly absorbed in the small intestine, then passed to the colon; the process of fermentation by the colonic microflora leads to an osmotic effect. This draws fluid into the lumen and causes an increase in gas production, resulting in abdominal pain, bloating, flatulence and diarrhoea in some individuals. There is strong evidence for the use of the lowFODMAP diet for IBS management and, now, it also appears to decrease functional gut symptoms in IBD. People with IBD are three times more likely to have IBS-style symptoms than the normal population.1 A small scale study on 52 patients with Crohn’s and 20 with ulcerative colitis found that one in two patients responded well to a low-FODMAP diet (improvement of at least 5/10 in symptoms) for abdominal pain, bloating, wind and diarrhoea.2 A UK study on 180 patients with IBS or IBD given low-FODMAP advice via a dietetic/nutrition-led clinic, found normal stools improved by 66% in the
IBD group. A higher adherence was associated with a longer duration of symptom improvement. Foods most often not reintroduced were wheat and onion (fructans) and dairy.3 It was concluded that the low-FODMAP diet seems to decrease functional gut symptoms in IBD. Another study on 88 people looked at symptoms and stool, finding a significant improvement on the lowFODMAP diet in symptoms and stool consistency.4 IS ONE FODMAP OF MORE CONCERN THAN ANOTHER?
A series of three-day fermentable carbohydrate challenges of fructans, galacto-oligosaccharides (GOS) and sorbitol were compared to glucose placebo on 32 patients with quiescent IBD. 12 of the patients had Crohn’s disease. Although a small scale study with limitations, it was found that fructans at high doses exacerbated symptoms.5 Another study6 shows that patients with active Crohn’s disease consume lower quantities of fructans and oligofructose than their inactive counterparts and healthy controls. This case control study used a food frequency questionnaire comparing 98 people with active Crohn’s disease, 99 with inactive Crohn’s disease and 106 healthy controls. A lower fructan intake was found in those with active
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