Gluten is always the bad guy. Even people without a diagnosis of gluten sensitivity or celiac disease find a gluten-free diet seems to be the cure-all for their gastrointestinal distress. But what if you aren’t allergic to gluten, but instead another carbohydrate — fructan? A new study indicates that more of us who believe we’re gluten-sensitive are allergic to fructan instead.
You may be allergic and not even know it
A recent study from Oslo University Hospital in Norway has outlined research into the carbohydrate fructan and how it affects the body. The team, which also included a researcher from Monash University and Alfred Hospital in Melbourne, looked at people with self-reported gluten sensitivity to see if there was another trigger to their GI symptoms. “Non-celiac gluten sensitivity,” the team wrote, “is characterized by symptom improvement after gluten withdrawal in absence of celiac disease.”
There’s admittedly still a lot we don’t know about gluten sensitivity. With no biomarkers for the disorder, the team had to look at other food substances that could cause symptoms in gluten-heavy foods. One of those is a fermentable sugar, fructan.
In the double-blind study, 59 people on a self-instituted gluten-free diet — and who did not have celiac disease — were randomly assigned to three diet groups. One group ate 5.7 grams of gluten, a second ate 2.1 grams of fructans and the third group was the placebo control group. Each participant consumed a muesli bar every day for seven days that contained one or the other carbohydrate, or the placebo bar.
Then after seven days, the participants were switched over to another group until they had each participated in three food challenges: gluten, fructan and placebo groups. The research team measured symptoms of gluten sensitivity through the three-week study. Overall, the team found that people experienced more of the classic gluten-intolerant symptoms after consuming fructan than they did when they ate gluten.
As many as 3.1 million Americans — myself included — eat a gluten-free diet because it relieves adverse gastrointestinal symptoms, but we could be going about it all wrong. We may be allergic to fructan and not even know it. Here’s how to figure that out.
1. You notice IBS symptoms
In all likelihood, if you don’t experience the symptoms of irritable bowel syndrome (IBS), then you are probably not gluten or fructan-sensitive. However, both gluten-sensitivity and fructan-sensitivity can cause the same symptoms. If you notice the same IBS symptoms when eating non-gluten foods, you might be sensitive to fructan.
These symptoms can include:
- Belching
- Bloating
- Gas
- Abdominal pain
- Abdominal distension
- Diarrhea
2. Eating gluten-free doesn’t eliminate the symptoms
Have you ever noticed that you feel gassy or bloated after eating a gluten-free pizza? Chances are, you’re actually allergic to fructan in the garlic or onions. That’s right — some vegetables contain naturally occurring fructans. According to Tufts Medical Center, the following foods contain a high level of fructans:
- Wheat products
- Onions
- Shallots
- Garlic
- Barley
- Cabbage
- Broccoli
- Pistachios
- Artichoke
- Chicory root
- Asparagus
While wheat is by and large the biggest culprit of fructan sensitivity, onions are the second most fructan-heavy food on the list.
3. You feel better on a low FODMAP diet
A low FODMAP diet helps people eliminate or reduce the number of specific carbohydrates they consume. FODMAP stands for Fermentable Oligosaccharides, Disaccharides, Monosaccharides and Polyols. As you may have guessed by now, fructan is a FODMAP food, so if you suspect you are sensitive to it, try eliminating the following foods from your diet for a bit:
- Fructose (including honey and fruits)
- Lactose
- Fructans
- Galactans (including lentils, soy and beans)
- Polyols (found in stone fruits and in sweeteners)
If you find your symptoms improve after being on a FODMAP diet for three weeks or more, then you might be allergic to fructan. A dietician or nutrition coach can help you challenge foods back into your diet slowly to determine which foods trigger your IBS-like symptoms.
How to reintroduce foods into your diet
If you want to try and add foods back into your diet from the FODMAP plan on your own, add one at a time and wait one or two days after consuming it to see if symptoms return. If they don’t, then move on to the next food on your list, testing each one individually. It’s a slow process but introducing foods back into your diet in this way can help you determine if you’re allergic to fructan, instead of gluten.
Do you think you might have a fructan allergy? Let us know in the comments below.
— Megan Winkler
