It’s not Gluten, it’s Fructan: Another Culprit of Digestion Problems

Everyone knows about the problems gluten can create, and yet only 1% of people actually have celiac disease. Many others think they are just gluten-sensitive – but in most cases it’s not true.

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Don’t blame gluten

Gluten has acquired a really sinister fame in the last decade, blamed for causing bloating, cramps, indigestion, and diarrhea in up to 12% of people. Actual celiac disease – when a person gets really sick after eating wheat, soy sauce, and other products with gluten – is pretty rare, but millions of people believe to have non-celiac gluten sensitivity (NSGS). They go on gluten-free diets and report significant improvement. However, recent studies show that gluten – a mixture of two proteins that acts like glue in dough – is not to blame at all in 80% of people with wheat sensitivity. Some cases are due to the irritable bowel syndrome (IBS – more on it here ), but more often it is fructan intolerance.

Introducing fructans

Fructans are a type of carbs that are mostly present in wheat, chickpeas, garlic, onions, dates and other dried fruit, and – interestingly – watermelon. Plants use fructans to store energy, but humans cannot digest them, so our intestine treats them like fiber. In fact, a particular fructan is also known as inulin (we have written about it before). As you probably know, fiber is extremely important and greatly improves digestion in most people. Inulin, in particular, lubricates the intestine, creates the feeling of fullness, and acts as a prebiotic, normalizing the bacterial flora of the gut. Adult males are advised to eat 35 grams of fiber every day, and females should eat 25 grams, including inulin. For most people, fructans are absolutely harmless and actually very healthy

Fructan sensitivity

However, circa 10% of people seem to be intolerant to fructans, in the same way you can be intolerant to lactose or gluten. The symptoms are very similar:

  • gas
  • diarrhea
  • bloating
  • constipation
  • pain
  • fatigue
  • lack of focus
  • nausea
  • rash

It’s the similarity of symptoms that makes a lot of people suspect gluten sensitivity. The issue is complicated by the fact that wheat is the main source of both fructans and gluten, so when such people go on a gluten-free diet, they feel an immediate relief!

However, a new study reveals how widespread fructan intolerance really is. People with suspected NCGS were given three types of muesli bars for the same periods of time: one had just gluten, the other just fructan, the third was a placebo. Participants reported the worst symptoms when they ate fructan bars (more info here). This shows that fructan sensitivity is much more widespread than NCGS but usually misdiagnosed.

What to do

Instead of just excluding wheat (which contains both gluten and fructans), try also including more those foods that contain fructans only – onions, garlic, shallots, cabbage, artichokes, broccoli, chickpeas, etc. If you find that your symptoms get worse after eating a meal of, for example, stewed cabbage with garlic and hummus, then probably it is fructans that are to blame.

At this point, you can try the low FODMAP diet, which is specially designed to exclude fructans and similar carbs. It is not the easiest, but it can produce dramatic effects. The most important thing is not to give up – before you decide that you are gluten-sensitive, explore other possbilities! The way to get better always starts with knowing exactly what you are suffering from.

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