Does a low FODMAP diet help IBS?
http://dtb.bmj.com/content/early/2015/0 ... 6.abstractDTB doi:10.1136/dtb.2015.8.0346
Abstract
Irritable bowel syndrome (IBS) is a common condition that can have a significant impact on a person's quality of life.1 The cause of IBS is unknown but several mechanisms have been proposed including visceral hypersensitivity, central sensitisation, abnormal gut motility and altered gut microbiota.2,3 IBS is challenging to manage and many patients report insufficient symptomatic relief from treatment.2 Approximately 60% of patients identify food as a trigger for their symptoms,2 and there has been interest in exclusion diets for managing IBS.4 Dietary adaptation is a common self-management strategy for patients with IBS, with many self-diagnosing intolerance to specific foods. This may lead to patients adopting over-restrictive or inappropriate diets.5
In recent years, a diet low in poorly absorbed short-chain carbohydrates, known collectively as FODMAPs (fermentable oligosaccharides, disaccharides, monosaccharides and polyols), has been advocated for the treatment of IBS.2 Here, we discuss the background to the FODMAP diet and review the evidence supporting its use for people with IBS.
Press Release
Very little evidence for cutting out certain carbs to ease irritable bowel
Value of FODMAP diet, developed in Australia to curb symptoms, questioned
PUBLIC RELEASE: 6-AUG-2015
There is very little evidence to recommend avoiding certain types of dietary carbohydrate, known as the FODMAP diet, to ease the symptoms of irritable bowel syndrome, or IBS for short, concludes a review of the available data in Drug and Therapeutics Bulletin (dtb).
IBS is characterised by abdominal pain/discomfort and altered bowel frequency in the absence of any obvious gut abnormalities. Symptoms can include abdominal bloating, which eating can worsen.
Up to one in five of the population is thought to be affected, with women twice as likely to develop IBS symptoms as men.
Treatment options include dietary and lifestyle advice, psychotherapy, and drugs to curb painful spasms and associated diarrhoea and/or constipation.
Dietary advice usually includes the recommendation to reduce intake of insoluble fibre, limit fresh fruit to three portions a day, take regular meals, avoid rushing food or eating on the go, and to steer clear of the artificial sweetener sorbitol.
The low FODMAP diet, which was developed in Australia, is based on the observation that certain types of short chain carbs are poorly absorbed by the small intestine and that IBS symptoms worsen when these are eaten.
These short chain carbs are present in wheat, onions, and legumes; milk; honey, apples, and high fructose corn syrup; and the artificial sweeteners used in confectionery (sorbitol and mannitol). They are rapidly fermented in the gut, increasing water volume and gases.
After assessing the available published evidence and the three UK guidelines on the management of IBS, dtb says that all the trials provide some evidence that patients feel the diet reduces some of the symptoms.
And one study indicates that the diet changes the profile of the bacteria in the gut, although what the clinical implications of this are, or, indeed, what the long term effects might be, are unclear, says dtb.
But data to back the use of a low FODMAP diet as an effective treatment to control symptoms "is based on a few relatively small, short term unblinded or single blinded controlled trials of varying duration," it cautions.
And dietary manipulation is not without its drawbacks as some people fail to maintain a balanced diet when trying dietary exclusions, says dtb.
While some guidelines suggest that a low FODMAP diet might be appropriate for motivated patients for whom other treatments have failed to relieve symptoms, this should only be done under the supervision of a dietitian with specialist expertise in this type of dietary intervention, it recommends.
And it concludes: "However, we believe that patients should be advised that there is very limited evidence for its use, the ideal duration of treatment has not been assessed in a clinical trial, and its place in the management of IBS has not been fully established."
Also
Diet low in FODMAPs Reduces Symptoms of Irritable Bowel Syndrome as Well as Traditional Dietary Advice: A Randomized Controlled Trial.
Gastroenterology. 2015 Aug 5. pii: S0016-5085(15)01086-0. doi: 10.1053/j.gastro.2015.07.054.
http://www.ncbi.nlm.nih.gov/pubmed/26255043METHODS:We performed a multi-center, parallel, single-blind study of 75 patients who met the Rome III criteria for IBS, enrolled at gastroenterology outpatient clinics in Sweden. Subjects were randomly assigned to groups that ate specific diets for 4 weeks: a diet low in FODMAPs (n=38) or a diet frequently recommended for patients with IBS (a regular meal pattern; avoidance of large meals; and reduced intake of fat, insoluble fibers, caffeine and gas-producing foods such as beans, cabbage, and onions), with greater emphasis on how and when to eat rather than on what foods to ingest (n=37). Symptom severity was assessed using the IBS severity scoring system, and patients completed a 4 day food diary before and at the end of the intervention.RESULTS:A total of 67 patients completed the dietary intervention (33 completed the diet low in FODMAPs, 34 completed the traditional IBS diet). The severity of IBS symptoms was reduced in both groups during the intervention (P<.0001 in both groups, before vs at the end of the 4 week diet), without a significant difference between the groups (P=.62). At the end of the 4 week diet period, 19 patients (50%) in the low FODMAP group had reductions in IBS severity scores ≥50, compared with baseline, vs 17 patients (46%) in the traditional IBS diet group (P=.72). Food diaries demonstrated good adherence to the dietary advice.CONCLUSIONS:A diet low in FODMAPs reduces symptoms of IBS symptoms as well as traditional IBS dietary advice. Combining elements from these 2 strategies might further reduce symptoms of IBS.