Good news for people following a low FODMAP diet! A recent study conducted by researchers at Kings College London measured the long-term effectiveness of a low FODMAP diet. The study followed 100 participants with IBS from baseline (pre-FODMAP restriction), through the elimination and rechallenge phases and for 1 year thereafter. Participants reported their gastrointestinal symptoms at baseline (before FODMAP restriction), at 4-8 weeks (after FODMAP restriction) and at 1 year (following a rechallenge phase). Dietitians taught participants how to implement the elimination and rechallenge phases, but participants made their own food selections (meals were not provided in this study).
Sixty-two percent of participants reported satisfactory relief of symptoms after the initial elimination phase and the majority of these participants (71%) continued to experience satisfactory symptom relief at 1 year. Almost all of the participants who responded to the diet at 1 year continued to avoid high FODMAP foods at least half of the time.
So what are the take home messages from this study? Reassuringly, the study shows that a low FODMAP diet improves IBS symptoms in both the short, and long-term. The study also suggests that some degree of FODMAP restriction may be necessary to maintain adequate symptom control in the long-term. It is here that we issue a note of caution. Given the adverse changes in gut microbial populations associated with long-term adherence to a low FODMAP diet, we always encourage people to enter a re-challenge phase and under the guidance of a dietitian, find an acceptable balance between the occasional inclusion of moderate and high FODMAP foods (naturally rich in healthy prebiotics) and adequate symptom control. In the long-term, we advocate people follow the least restrictive diet necessary. Further research into the rechallenge and long-term maintenance phases of the diet is warranted.
Reference:
Martin, L., van Vuuren, C., Seamark, L. (2015) Long term effectiveness of short chain Fermentable carbohydrate (FODMAP) restriction in patients with irritable bowel syndrome. Gut, 64: A51-A52.
