The Low FODMAP Diet

The term FODMAP is an acronym that stands for fermentable oligo-, di-, mono-saccharides and polyols. Even though scientific evidence does not support a low FODMAP diet for weight control, the low FODMAP diet has become an increasingly popular dieting trend for weight loss. This diet was developed by researchers at Monash University to help patients with medically-diagnosed irritable bowel syndrome (IBS) control their gastrointestinal (GI) symptoms.¹¹ IBS is a functional GI disorder without a known cause, and is a difficult health condition to treat.¹² There is no cure for IBS, which impacts more than 11% of the population worldwide.¹³ Symptoms typically consist of abdominal pain, bloating, diarrhea and/or constipation.¹⁴ IBS negatively impacts quality of life and often contributes to a considerable economic burden in terms of health-care costs for these patients and their families.

FODMAPs are found in a variety of nutrient-dense foods, such as fruits, vegetables, dairy, wheat and in sugar-free sweeteners. When foods and sugar-free sweeteners high in FODMAPs are consumed, the small, nondigestible, fermentable carbohydrates are poorly absorbed in the small bowel resulting in GI distress in IBS patients. Each patient can tolerate different types and amounts of FODMAPS, therefore the low FODMAP diet is a three-phase, individualized approach.¹⁵ During the first 4-8 weeks of the low FODMAP diet, the patient completely eliminates all FODMAPS. Since this first phase of the diet is the most restrictive and most challenging phase, it’s important for the patient to work with a registered dietitian to make sure that they follow the diet correctly.¹⁵ During phase two, the reintroduction phase, foods are gradually added back into the diet, while monitoring symptoms, in order to ensure nutritional adequacy. Often a food-symptom log will help determine which specific FODMAPs are problematic. Phase three is the personalization phase, which eliminates only the FODMAPs that cause GI discomfort. The low FODMAP diet is effective in reducing GI symptoms in up to 86% of IBS patients.¹⁶

In addition to limiting or avoiding FODMAPs in foods, patients must also consider the non-food sources of FODMAPs, the sugar-free sweeteners, which include the polyols also known as sugar alcohols. We do not have the enzymes to completely metabolize sugar alcohols, therefore, they provide less calories than sugar and do not contribute to caries. Sugar alcohols are common ingredients in sugar-free chewing gum, medications, dietary supplements, chewable vitamins, candy, breath mints, throat lozenges, oral melts and other oral care products. Research suggests that frequent use of the polyol, xylitol, is associated with a significant reduction in the incidence of dental caries.¹⁷ Sugar alcohols are often recommended by oral healthcare providers as part of an overall preventive treatment for patients at high caries risk.¹⁸ Today, there are more oral care products than ever before in the marketplace containing different types of sugar alcohols and these products are often recommended to patients suffering with radiation-induced xerostomia.¹⁹ Erythritol, xylitol, sorbitol, mannitol, maltitol, lactitol, and isomalt are sugar alcohols.¹⁷ Chewing sugar-free gum made with sugar alcohols protects the teeth from cavity-causing bacteria by promoting the flow of saliva. This increased saliva and other noncariogenic properties are the reasons why sugar alcohols are often used as a sweetener in sugar-free chewing gum and the American Dental Association and the U.S. Food and Drug Administration recognize sugar alcohols as beneficial to oral health.²⁰

Even though sugar alcohols have been shown to potentially benefit oral health, they are FODMAPs and must be either limited or avoided by dental patients suffering from IBS. To take this a step further, if any dental patient, even patients without IBS, ingests sugar alcohols in large quantities, this can result in diarrhea and dehydration. Ingesting sugar alcohols has been shown to cause intestinal dysmotility, flatulence, abdominal pain and diarrhea in patients with IBS.²¹

When taking a medical history, the oral healthcare provider should inquire if the patient is following a low FODMAP diet for medically diagnosed IBS. When treating these patients, dental practitioners must be aware of the sugar alcohol content of dental products they are recommending. In many cases, especially if the patient is in the first phase of the low FODMAP diet, strict dietary avoidance of all FODMAPs is vital for the success of the diet. Therefore, a xylitol-based caries program or xylitol containing chewing gums and lozenges to treat xerostomia should not be recommended as part of the dental treatment plan for a patient with IBS.

The bottom line: Oral healthcare providers have the opportunity to provide individualized and supportive guidance when recommending dental products to patients with IBS who are following a low FODMAP diet.