Fructans belong to the FODMAP oligosaccharides. Oligosaccharides are multiple carbohydrates made up of 3 to 9 simple carbohydrates. In other words, large chains of sugars. For the sake of completeness, these are made up of several fructose molecules with one sucrose molecule. Another name for fructans is fructo-oligosaccharides.
Fructans are not absorbed into our bodies, but after passing through the stomach, small intestine and large intestine, they leave the body in the form of faeces. Our bodies cannot ‘cut up’ the carbohydrate chains of the fructans with enzymes, so it cannot be absorbed into the body through the intestinal wall. Fructans are therefore transported to the large intestine, where they attract moisture and are fermented by intestinal bacteria, releasing gases and acids.
The remarkable thing is that, in principle, no one can break down fructans. The only difference is that one person’s gut reacts much more violently to it than another person’s gut. As a result, not everyone suffers from fructans.
Fructans are found in certain fruits, vegetables and cereal products. Some examples of products that are high in fructans are: garlic, onion, artichoke, asparagus, wheat, dates, leeks, cashew nuts, pistachio nuts, and split peas.
Gluten are known to cause many problems. Celiac disease is the disease in which gluten plays a role. Celiac disease is an autoimmune disease that is triggered by ingesting food containing gluten. Gluten are found in wheat. Fructans are also found in wheat. This is probably why, when you react to wheat, you immediately think of gluten. But fructans are found in many more things, such as onions, garlic, beans and leeks. People who are gluten intolerant can eat these two vegetables because they do not contain gluten. People who are sensitive to fructans cannot eat these vegetables without experiencing symptoms.
But how is it possible that eating gluten-free gives me fewer symptoms if I have a fructan intolerance? Gluten-free products contain no wheat and therefore fewer fructans. Spelt, for example, is often used as a wheat substitute and as well as containing less gluten, it also contains less fructans. Because your fructan intake is lower, you’ll have fewer symptoms of gluten intolerance.