Researchers studying gluten sensitivity were surprised to find that most people’s symptoms after eating wheat weren’t due to gluten. The cause of symptoms in most cases was FODMAP sugars. FODMAPS are sugars found in wheat and many other foods. The study looked at people with non-celiac gluten sensitivity and IBS (celiac disease had been ruled out as a cause of symptoms). When all of the research subjects were taken off of food that contained FODMAPS, they improved significantly. When they reintroduced only gluten and not the other FODMAP foods, only 8% of people with “Non-Celiac Gluten Sensitivity” actually reacted to gluten.
These carbohydrates are found in wheat and other foods such as apples, watermelon, onions, and garlic. FODMAP carbohydrates are not well-absorbed in general. Their poor absorption is problematic in some people and creates gas, bloating, diarrhea, depression, joint pain, and fatigue.
The results of this study are essential. If people with gluten sensitivity react to FODMAP carbohydrates, the treatment of choice is not a gluten-free diet but a low FODMAP diet. The two diets are very different.
What are FODMAPS?
FODMAP stands for fermentable oligo-, di-, monosaccharides, and polyols These are a group of carbohydrates that commonly cause digestive problems such as diarrhea, constipation, bloating, and gas. FODMAP intolerance is connected with up to 75% of cases of irritable bowel syndrome.
FODMAPs are found in a wide range of foods in varying amounts. Some foods contain just one type, while others contain several. They are many foods. Common problematic FODMAP containing foods include wheat, apples, onions, garlic, honey, legumes, and milk. But, the list of FODMAP containing foods is much more extensive.
The main dietary sources of the four groups of FODMAPs include:
- Oligosaccharides: Wheat, rye, legumes, and various fruits and vegetables, such as garlic and onions.
- Disaccharides: Milk, yogurt, and soft cheese. Lactose is the main carb.
- Monosaccharides: Sweeteners such as honey and agave nectar. and fructose (fruit sugar)
- Polyols: Certain fruits and vegetables including blackberries and lychee, as well as some low-calorie sweeteners like those in sugar-free gum
Diagnosis of FODMAP Intolerance
There is no laboratory test for FODMAP intolerance. The diagnosis is made after evaluation for other causes of symptoms followed by a FODMAP elimination diet. The diet must be done correctly to assess whether or not FODMAP intolerance is present. The diet is complicated and I recommended a consult with a registered dietitian to discuss the proper implementation of the diet. If the diet is not done correctly, FODMAP intolerance may be missed as a diagnosis.
Treatment For FODMAP Intolerance
The treatment for FODMAP Intolerance is a low FODMAP diet. A two-three week trial period is recommended. Typically some improvement will be seen in that period. If the diet has been done correctly and no improvement has been made, it is unlikely the person has FODMAP intolerance. If there is an improvement, the low FODMAP diet should be continued for 6 weeks. A methodical reintroduction diet is recommended after 6 weeks on a low FODMAP diet. The diet is not meant to be a long term solution to digestive problems. Long-term adherence to a low FODMAP diet causes negative changes in the gut microbiome.
Is The Low FODMAP Diet Gluten-Free?
No. It is not a gluten-free diet. It is low in gluten but it is not strictly gluten-free. For example, some people on a low FODMAP diet can tolerate sourdough spelt bread. The fermentation process breaks down the FODMAP sugar in spelt. Spelt bread contains gluten and would not be allowed on a gluten-free diet. This is one example where gluten is allowed on the Low FODMAP diet. There are others beyond the scope of this article.
The Low FODMAP Diet Is Here To Stay
The link between these carbohydrates and symptoms is now well accepted, and the Low FODMAP diet a relief for many. Also, the Low FODMAP diet is now the primary dietary intervention for IBS. Since there is currently no test for FODMAP intolerance, proper implementation of the diet is imperative to determining the presence or absence of FODMAP intolerance. I again emphasize the importance of consulting a dietitian familiar with the diet. Doing it without guidance is difficult.
Following is a list of valuable resources for anyone interested in learning more about a Low FODMAP diet. Low FODMAP product lines and food delivery services are now available.
Recommended resources for a low FODMAP diet:
- Monash University Low Fodmap App for I-phone and Android
- Monash University Website: The leaders in research and information on the low FODMAP diet
- Patsy Catsos, RD– Fantastic website with information on following a low FODMAP diet
- Pinterest site with photos of low FODMAP products
- Kate Scarlata, RD A terrific blog with recipes and information on a low FODMAP diet
- Book: A great consumer-friendly, resource for anyone on a Low FODMAP Diet. Written by Dr. Sue Shepard and Peter Gibson from Monash University
Recent Research On The Low FODMAP Diet
- 2021 Low FODMAP diet in IBS-D Improves Quality Of Life
- 2021 Low FODMAP diet for functional abdominal pain in children (study in progress)
- 2020 Low FODMAP diet and Inflammatory Bowel Patients with IBS; effect on microbiome