Q: What is a FODMAP and how do I know if I should be avoiding FODMAPs?
A: Dr. Sue Shepherd, PhD discovered FODMAPs , or Fermentable Oligosaccharides, Disaccharides, Monosaccharides And Polyols, aggravated many digestive complaints and subsequently developed the low FODMAP diet in 1999. Foods high in FODMAPs include honey, apples, mango, pear, watermelon, high fructose corn syrup, leek, onion, wheat, rye, barley, inulin, milk, yogurt, kidney beans, lentils, chickpeas, apricots, avocado, cherries, nectarines, plums, mushrooms, sorbitol, mannitol and xylitol.
Foods low in FODMAPs include meat, poultry, fish, oils, bok choy, bean sprouts, bell peppers, butter lettuce, carrots, celery, chives, corn, eggplant, green beans, tomatoes, potatoes, spinach and ripe bananas.
Carbohydrate digestion and absorption is surprisingly complex. In order for carbohydrates to be properly digested, the wall (“brush border”) of your small intestine has to produce specific enzymes. If you do not optimally produce the enzymes or if the brush border of your small intestine is inflamed, carbohydrate digestion will be compromised. One gene, succinctly referred to as MGAM, codes for the intestinal brush border enzyme maltase-glucoamylase alpha-glucosidase which is one of two membrane-bound digestive enzymes required for the final stage of starch digestion. Many people have single nucleotide polymorphisms (SNPs) or mutations in the MGAM gene which could lead to suboptimal enzyme production and activity. Once carbohydrate digestion is compromised, the microorganisms that populate your digestive tract, known as your microbiome, will feed on the carbohydrates by fermentation. Candida, in particular, is one microorganism that feeds on undigested carbohydrates. Carbohydrate digestion by your microbiome can lead to dysbiosis (an imbalance of the microbiome), “leaky gut,” abdominal bloating and distension, flatulence, abdominal pain, nausea, changes in bowel habits, diarrhea and constipation. These symptoms are commonly resolved by the low FODMAP dietary approach.
The low FODMAP diet has two phases. The first phase is a strict elimination diet when all high FODMAP foods are avoided. The initial phase should be followed for 6-8 weeks. After the initial phase, an expert such as a naturopathic physician will guide you through the second phase. The second phase is a challenge phase where you try one food at a time and wait for symptoms. The purpose of the second phase is to personalize your low FODMAP diet so a less restrictive, clinically effective, long-term diet can be established.
If you have ever been diagnosed with Irritable Bowel Syndrome (IBS), if you have many symptoms related to your digestive system or if you have MGAM SNPs, a low FODMAP diet might be highly beneficial. Please ask your physician for guidance about how to properly initiate the low FODMAP diet.
1. Vincent-Chong, Vui King et al. “Genome Wide Analysis of Chromosomal Alterations in Oral Squamous Cell Carcinomas Revealed over Expression of MGAM and ADAM9.” Ed. Tao Jiang. PLoS ONE 8.2 (2013): e54705. PMC. Web. 27 Apr. 2015.
2. "The Low FODMAP Diet Approach: What Are FODMAPs?" - AboutIBS.org. International Foundation for Functional Gastrointestinal Disorders, 15 Sept. 2014. Web. 24 Apr. 2015. <http://www.aboutibs.org/site/treatment/low-fodmap-diet/what-are-fodmaps>.
3. "Low FODMAP Diet." Shepherd Works. Web. 24 Apr. 2015. <http://shepherdworks.com.au/disease-information/low-fodmap-diet>.
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