If you have been diagnosed with IBS by your doctor he might have suggested you follow a Low FODMAP diet. If you are anything like me you probably silently went... FODMAP what??? Well, let me tell you, it sounds worse than it is. Let's unpack what FODMAPs are all about.
FODMAP is such a strange term because it's an acronym that stands for Fermentable Oligosaccharides, Disaccharides, Monosaccharides And Polyols. Still no clue? Let me cheer you up and tell you we have all been there. It's easier to understand than you think because:
It's all about sugar!
Yes, it's true! It's all about sugar or more precisely about sugar molecules. The term that appears in half of the words making up FODMAP is "saccharide". A saccharide is nothing more than a sugar molecule. These molecules can be chained together or stand on their own. So, a Monosaccharide is a stand-alone sugar molecule, a Disaccharide is a strand of two sugar molecules bonded together and an Oligosaccharide is a strand of 3-10 sugar molecules bonded together.
The only exception to the sugar molecule rule is the P in FODMAP. Polyols are a long chain not of sugar molecules but of sugar alcohols and can be made of hundreds or even thousands of molecules.
So, basically, we can say that FODMAPs are mostly short-chained carbohydrates, also known as sugars. These naturally occur in food but also in food additives. But how does that play a role in the food we actually eat?
The FODMAP Food Groups
Each FODMAP group of carbohydrates actually stands for one or more specific subgroups of sugar molecules of which we know that they can't be completely digested and absorbed in the intestine. As a result, they can trigger IBS symptoms in people with sensitive guts. Head over to my previous post on IBS for more information on why FODMAPs cause IBS symptoms.
Let's take a closer look at the FODMAP acronym and at the food groups that might wreak havoc in your intestine and debunk the FODMAP myth once and forever.
The process through which gut bacteria ferment undigested carbohydrates. This produces gases, acidity or alcohol.
Oligosaccharides are made of 3 to 10 sugar molecules. For IBS sufferers there are two groups of oligosaccharides that are known to cause trouble with digestion.
Fructans (fruct-oligosaccharides or FOS): FOS are made of one glucose molecule which is bonded together with two or more fructose molecules. It is found in foods such as wheat, rye, barley, artichokes, onions, garlic, fruit, and some vegetables.
Galactans (galacto-oligosaccharides or GOS): GOS are made of a glucose molecule that is combined with two or more galactose molecules. It is found in foods such as silken tofu, beans, legumes, nuts, and some vegetables.
Disaccharides are made of two sugar molecules.
Lactose is the one saccharide that might trigger IBS symptoms. It is made of one galactose and one glucose molecule. Lactose is found in all products containing milk, such as yogurt, cream, butter, soft cheese, and ice cream. In order to absorb lactose, our bodies need the enzyme lactase to break down the sugar. If you don’t have this enzyme, then lactose could be the culprit for your IBS symptoms.
Monosaccharides are stand-alone sugar molecules. People who suffer from IBS mostly struggle with fructose. As a simple sugar, fructose doesn't require digestion. However, it relies on sugar transporters (Glut-5) that are located in the wall of the small intestine for absorption into the body. If this transport system is impaired, fructose mostly only becomes a problem when it is found in excess of glucose in foods such as honey, apples, high fructose corn syrup. This is because glucose transports fructose across the small intestinal barrier and thus helps its absorption. If fructose is, however, in excess of glucose and the sugar transport system is impaired it causes fructose malabsorption.
Polyols are long-chained sugar alcohols. They can be found in certain vegetables such as mushrooms and fruits such as apricots and blackberries or as artificial sweeteners. On labels look for things like sorbitol, mannitol, maltitol, xylitol, lactitol, and erythritol. Attention also isomalt is a polyol.
FODMAP Content in Foods
Well, this hasn't been as difficult to understand as it seemed, am I right? Still, you might ask yourself how this knowledge of what FODMAPs are will help you navigate food. After all, it's impossible to guess the FODMAP content of a food. Fear not, scientists have done the amazing work for us to know the FODMAP content of the foods. The team at Monash University are experts at measuring FODMAP content through laboratory analysis and distribute this information using their mobile phone app, the Monash University FODMAP Diet App. The app lets you know whether foods are low, moderate or high in certain FODMAPs. Similarly, the team behind the FODMAP Friendly App has created an app that lets you know the FODMAP content of foods. Download both of these apps and familiarise yourself with how they work. They are indispensable tools when navigating the Low FODMAP diet.