A new way to manage Irritable Bowel Syndrome (IBS) is quickly gaining support amongst the medical community, and many IBS sufferers are seeing positive results.
Dr Susan Shepherd, an Australian dietician and researcher, led a presentation on the low-FODMAPs diet last month at the American College of Gastroenterology conference in Washington.
The theory is that people with IBS have difficulty digesting certain types of carbohydrate, leading to symptoms such as gas, bloating, abdominal pain, constipation or diarrhoea.
Small studies in the UK and Australia have shown that the diet reduced symptoms in around 75% of IBS sufferers, which makes it a more successful approach than many other dietary or medical interventions. In a controlled study published some weeks ago in the Journal of Human Nutrition and Dietetics, the low-FODMAP diet improved IBS symptoms in more than 80% of the adults tested (1).
FODMAP stands for Fermentable Oligo-, Di- and Mono-saccharides and Polyols. These are a group of short-chain carbohydrates and sugar alcohols present in food. They comprise fructose, lactose, fructans, galactans and polyols.
Certain foods are particularly high in FODMAPs. These include milk and unripened cheeses, which are rich sources of lactose, and wheat and rye which are high in fructans. Sources of galactans and polyols include legumes, some fruits, and sweeteners such as sorbitol and xylitol.
FODMAPS have a number of characteristics which can make them troublesome for those with IBS and other digestive problems.
- They are poorly absorbed in the small intestine.
- They tend to draw liquid into the gut, affecting movement in the gut.
- They are quickly fermented by bacteria in the gut, producing gas and bloating.
The low-FODMAPs diet recommends eliminating all suspect foods for 6-8 weeks, and then gradually reintroducing these foods in order to identify which ones are causing digestive problems.
As the low-FODMAPs diet is rather restrictive, it is advised that those with IBS should only follow the diet under the guidance of a qualified health practitioner.
There are some potential drawbacks to the low-FODMAPs diet, which can be overcome with a little careful planning. For example, those restricting FODMAP foods should be sure to include other sources of fibre in their diet. Fibre is an important nutrient for bowel health, and this can be provided by grains such as quinoa and rice, as well as well-tolerated fruits and vegetables.
The FODMAP diet also excludes many ‘prebiotic’ foods, which help to feed good bacteria in the gut. Good bacteria help to produce vitamins, support the immune system and prevent the growth of harmful bacteria. It may therefore be helpful to include probiotic supplements or probiotic foods in order to help boost levels of good bacteria in the gut.
Written by Nadia Mason, BSc MBANT NTCC CNHC
1. Staudacher HM et al. Comparison of symptom response following advice for a diet low in fermentable carbohydrates (FODMAPs) versus standard dietary advice in patients with irritable bowel syndrome. Journal of Human Nutrition and Dietetics. October 2011. 24(5):487-495
2. Image courtesy of Ambro