FacebookEveryone has their preferences when it comes to food but sometimes your body disagrees with your choices. Individuals with digestive disorders like irritable bowel syndrome (IBS) often have trouble processing even healthy foods like fruits and vegetables. The low FODMAP diet was developed for these individuals and others whose digestive systems are sensitive to certain categories of food.
The acronym FODMAP stands for fermentable oligosaccharides, disaccharides, monosaccharides, and polyols. Examples of FODMAPs include high-sugar fruits, cruciferous vegetables, and dairy products.
The low FODMAP diet isn’t necessarily a list of foods you can and can’t eat. Rather, the goal is to limit your intake of foods that are difficult to digest and to determine which FODMAP foods your body can process in small to moderate amounts.
Before you start memorizing a FODMAP food list, it’s important to understand each of the different categories and the foods they include. Here we’ll dive into the details of one category of FODMAPs: monosaccharides.
An In-Depth Look at Monosaccharides
Monosaccharides are also known as simple carbohydrates or sugars, and they are the base unit from which carbohydrates are constructed. Short-chain carbohydrates are built from up to ten monosaccharides linked by glycosidic bonds. For example, disaccharides are constructed of two monosaccharides. Polysaccharides, also known as long-chain carbohydrates, consist of linked chains of 10 or more monosaccharides.
Examples of monosaccharides include fructose, glucose, and galactose. Fructose is the monosaccharide referenced in the FODMAP acronym. The human body has difficulty digestive excessive amounts of fructose, but individuals with IBS have an even more limited capacity to digest and absorb this monosaccharide. A low FODMAP diet may still include fruits, but primarily low-sugar fruits.
What Foods Contain Monosaccharides?
The monosaccharide is the most fundamental type of sugar – they cannot be broken down any further. They’re typically colorless, sweet-tasting, crystalline solids that can be dissolved in water. As mentioned above, the most common dietary monosaccharides are fructose, glucose, and galactose.
In the context of the low FODMAP diet, fructose is the primary concern. Fructose is a natural component of sweet foods like honey, sugar cane, and fruit but is also present in smaller amounts in certain vegetables.
Foods that contain significant amounts of fructose include:
- Apples
- Cherries
- Mango
- Pears
- Dried fruit
- Nectarines
- Peaches
- Plums
- Watermelon
- Agave syrup
- High fructose corn syrup
- Honey
- Asparagus
- Broccoli
- Jerusalem artichokes
- Sugar snap peas
While most fruits contain fructose, some of them are safe for inclusion on a low FODMAP diet. These are the fruits that contain a higher ratio of glucose to fructose which helps improve digestibility and fructose absorption. Examples of low FODMAP fruits include blueberries, cantaloupe, grapes, and pineapple.
When selecting low FODMAP foods, it’s important to know the difference between high-fructose foods and other sweet foods. Table sugar, for example, is a sweetener that doesn’t contain significant amounts of fructose, but honey and agave are high in FODMAPs. High-fructose corn syrup is, of course, loaded with fructose as well and best avoided on a low FODMAP diet.
Do They Provide Any Health Benefits?
Fructose is not necessarily unhealthy, though a significant portion of the population have some trouble digesting it – some more than others.
Monosaccharides are absorbed in the small intestine with the help of transporter proteins called GLUT2 and GLUT5. The GLUT2 transporter protein supports the uptake of fructose when it is paired with an equal or greater amount of glucose. It acts fairly quickly in comparison to GLUT5 which, while slower in action more limited in capacity, can transport fructose when it is consumed in excess of glucose.
Excessive amounts of fructose are prone to malabsorption for everyone, but roughly one-third of the population has some degree of fructose malabsorption. For these individuals, the GLUT2 and GLUT5 transporter proteins fail to work properly which results in fructose passing through the small intestine into the large intestine where it is poorly absorbed. In this environment, fructose acts as a food source for gut bacteria and may contribute to digestive symptoms like gas, bloating, abdominal pain, diarrhea, and constipation.
Fructose itself is not inherently unhealthy. It’s simply a natural sugar found in whole fruit. Fructose from added sugars, on the other hand, is not healthy. When consumed in balance with glucose, it is more easily digestible and can provide a valuable source of readily available energy.
Monosaccharides and a Low FODMAP Diet
FODMAPs can be difficult for anyone to digest in large quantities but particularly for individuals with IBS. By limiting your intake of high FODMAP foods like fructose-rich fruits and sweeteners, you may find relief from uncomfortable digestive symptoms like gas, pain, and bloating.
If you’re following a low FODMAP diet for IBS or other digestive concerns, remember that monosaccharides are only one piece of the puzzle. You can learn more about FODMAPs here.
