Diet Tips:Research article: Not all FODMAPs are equal

By Caroline Tuck (APD, PhD Candidate)

An interesting study was published in 2013 about the effects of different FODMAPs.

FODMAP is an acronym for a group of carbohydrates that have been shown to cause symptoms in people with irritable bowel syndrome (IBS). The acronym stands for Fermentable Oligosaccharides, Disaccharides, Monosaccharides and Polyols and includes the following carbohydrates:

·         fructose

·         lactose

·         sugar polyols (including sorbitol and mannitol)

·         fructans

·         galactooligosaccharides

Although these 5 sugar subgroups have been grouped together, they appear to have a different effects on the gut. This study compared the effects of fructose and fructans.

Sixteen healthy volunteers participated in the study. Subjects were given 4 different solutions: glucose (a well-digested/absorbed sugar) which acted as a control (or placebo); fructan; fructose or fructose with added glucose. After consuming each solution, subjects underwent MRI scans to assess the water content of the small intestine and the gas content of the large intestine.

The study showed that fructose caused an increase in the water content of the small intestine (probably due to osmosis), while fructans increased the gas content of the large intestine. The study highlights that different FODMAPs behave differently, even within the same gut. It also helps us to understand why different FODMAP may contribute to different IBS symptoms. The study suggests that dietitians should tailor a person’s low FODMAP diet to mitigate specific IBS symptoms.  

If you would like to read the full research article, the reference is here: Murray, K., V. Wilkinson-Smith, C. Hoad, C. Costigan, E. Cox, C. Lam, L. Marciani, P. Gowland and R. C. Spiller (2014). "Differential effects of FODMAPs (fermentable oligo-, di-, mono-saccharides and polyols) on small and large intestinal contents in healthy subjects shown by MRI." Am J Gastroenterol 109(1): 110-119.

           

Diet Tips:Research update: Fermentable oligosaccharide, disaccharide, monosaccharide and polyol content of foods commonly consumed by ethnic minority groups in the United Kingdom

By CK Yao (APD and PhD candidate)

 

We have recently published an article on the FODMAP content of top 20 foods commonly consumed by minor ethic groups in the UK. This research was part of a collaborative work with the King’s College research group based in London.

The project was undertaken on the basis of an increasing need to make the low FODMAP diet more applicable to different ethnicities/cultures around the world. In the UK, the Asian and African/Carribean British ethnic groups form two of the largest ethnic minority groups. Whilst the prevalence of IBS in these groups is unknown, it was a good opportunity to diversify the contents of the low FODMAP diet.

The top 20 foods were identified by the research team in King’s college London and with the help of dietitians from around Europe who had previously received training in the use of the low FODMAP diet. These included:

TOP 20 SELECTED FOODS

Fruits: Fresh: Breadfruit, plantain, tamarind Processed: Ackee (tinned in brine); Guava (tinned in syrup)

Vegetables: Fresh: Cassava, cho cho, karela, taro, yam Processed: Callaloo

Legumes: Chana dal, urid dal (dry and boiled)

Herbs & spices: Fenugreek leaves

Nuts and seeds: Egusi seeds and white poppy seeds

Samples were collected following the Monash protocol, freeze-dried (if fruit or vegetables) and then shipped across to the laboratory of the Monash FODMAP team here in Australia. Measurement of FODMAP content was performed by the Monash FODMAP team. The foods tested are now listed in the Monash University Low FODMAP diet app.  Only foods that are laboratory tested are listed in our app (See under UK foods in the app).

 A brief summary of the findings are:

·         Fructans and galacto-oligosaccharides were present in most foods

·         For typical serving sizes; taro, karela, cho cho, cassava were HIGH in FODMAPs

·         Chana dahl and urid dahl (which are legumes) were LOW in FODMAPs

·         All fresh fruits tested were LOW in FODMAPs per serve eaten

 To read a full version of this paper, please see the reference below:

PrichardR, Rossi M, Muir J, Yao C, Whelan K, Lomer M. Fermentable oligosaccharide,disaccharide, monosaccharide and polyol content of foods commonly consumed byethnic minority groups in the United Kingdom. International Journal of FoodSciences and Nutrition 2016:1-8.

 

Diet Tips:NEW US RESEARCH: The Low FODMAP diet superior for the relief of abdominal pain and bloating

The Low FODMAP Diet & mNICE Diet Compared

By Dr Jane Varney

 

An interesting study was published by our colleagues at the University of Michigan this week (1). The US study compared the effect of two dietary interventions on IBS symptoms in people with diarrhoea predominant IBS (IBS-D). The interventions in question were the low FODMAP diet and a more traditional dietary approach, known as mNICE (modified guidance from the National Institute for Health and Care Excellence).

Ninety-two eligible subjects were recruited into the study, all of whom had IBS-D and most of whom were female (71%). Participants were randomised to either a low FODMAP diet or the mNICE diet for 4 weeks. Because this was also not a feeding study, a dietitian taught participants how to follow their respective diets, but participants were required to put this advice into practice and prepare their own meals. Resources developed at Monash and Michigan Universities were used to teach participants how to follow the low FODMAP diet. Guidance given to the mNICE group included to eat small frequent meals, to avoid trigger foods and to avoid excess alcohol and caffeine. This guidance was considered ‘modified’, because high FODMAP foods were not specifically excluded as would typically be the case on this diet.

 

 The study revealed a number of interesting findings:

·         The diets were equally effective at providing ‘adequate relief’ of overall IBS symptoms, with improvements experienced in 41% of participants in the mNICE group and 52% of participants in the low FODMAP group.

·         More participants in the low FODMAP group experienced an improvement in abdominal pain, 51% versus 23%, p=0.008.

·         The greatest benefit of the low FODMAP diet was for relief of abdominal pain and bloating, with improvements in stool consistency, stool frequency and urgency also observed in this group.

Take home messages:

·         The low FODMAP and mNICE diets improve symptom control in roughly half of all people with IBS-D.

·         The low FODMAP diet may be a superior choice for the relief of some symptoms, namely abdominal pain and bloating

 

1. Eswaran SL, Chey WD, Han-Markey T, Ball S, Jackson K. A Randomized Controlled Trial Comparing the Low FODMAP Diet vs. Modified NICE Guidelines in US Adults with IBS-D. Am J Gastroenterol. 2016.

Link to full research article: http://www.nature.com/ajg/journal/vaop/ncurrent/full/ajg2016434a.html 

 

Diet Tips:Adding glucose to high FODMAP foods – does it really help?

By Marina Iacovou (PhD Candidate and Accredited Practising Dietitian)

In an earlier blog post this year (http://bit.ly/1WvWU5Y) we speculated that although early studies suggested adding glucose to fructose may improve tolerance, the strategy was not looking promising – instead all it was doing was adding more sugar to the overall diet.  There was confusion around this strategy with individuals adding glucose to all FODMAPs, not just fructose, which is the only FODMAP that could benefit from glucose addition. Consuming glucose tablets became common practice for many people when eating onion and garlic, foods rich in fructans, not fructose, which scientifically will not improve symptoms.

We can now confidently tell you that adding glucose to foods to help with the absorption of FODMAPs, even fructose, does not work.

One of our PhD candidates, Caroline Tuck, has published work on this very topic. If you want to read the full publication, please click here.

A brief summary of the study and its findings:

• Patients with a positive fructose breath test (“fructose malabsorption”) and functional bowel disorders such as IBS, were recruited. Healthy participants were recruited as a reference/control group
• Participants were provided with 6 different sugar solutions (PART A) – some acted as control solutions (glucose only) and others were combinations of fructose and glucose, and fructans and glucose which were compared to fructose alone and fructan alone
• Additional studies (PART B) were undertaken. where glucose was added to whole foods high in excess fructose
• It was a series of two randomised controlled, double or single-blinded crossover trials – this means that the participants (and in part A the researchers) were not aware what solutions were being consumed and the solutions were given in a random order. As such the results are more reliable
• Overall, breath hydrogen scores and patient symptoms did not improve with the addition of glucose to fructose or fructan solutions, or to whole foods
• Breath hydrogen responses in healthy participants were similar to patients with functional bowel disorders – showing that “fructose malabsorption” is normal
• The results of the study, question the reliability of breath hydrogen tests in a clinical setting. 

So we can conclude that: 1) breath hydrogen tests, particularly to fructose, are unreliable – this is consistent with a previous study we posted about http://bit.ly/2fSaVcn and 2) Overall, the strategy of adding glucose to drinks or foods to lessen the effects of dietary FODMAPs on functional gastrointestinal symptoms, has no evidence.

Some of you may have been doing this already – taking glucose tablets with high fructose foods. If you really feel it helps, you can continue, but remember these points:

• Your total sugar intake will increase significantly
• Your tolerance to FODMAPs, including fructose, can fluctuate over time, so maybe this strategy is working because your tolerance to fructose has improved and you can drop the glucose without significant symptoms

Something to consider…

Tuck CJ, Ross LA, Gibson PR, Barrett JS, Muir JG. Adding glucose to food and solutions to enhance fructose absorption is not effective in preventing fructose-induced functional gastrointestinal symptoms: Randomised controlled trials in patients with fructose malabsorption. J Hum Nutr Diet. 2016.