Locations:
Search IconSearch

Could You Have a Fructan Intolerance?

A low-FODMAP elimination diet can help identify your symptoms

Person during a consultation with their dietitian.

Maybe you’ve tried going gluten-free and it didn’t seem to ease your stomach problems. Maybe you’ve been given the general diagnosis of irritable bowel syndrome but still can’t figure out exactly which foods upset your stomach.

Advertisement

Cleveland Clinic is a non-profit academic medical center. Advertising on our site helps support our mission. We do not endorse non-Cleveland Clinic products or services. Policy

Maybe it’s actually a fructan intolerance.

Fructans are a type of carbohydrate, or sugar, that some people have a hard time digesting. But the symptoms of fructan intolerance often mimic those of gluten intolerance, and to make things even more complicated, some foods have both gluten and fructans — so it can be extra difficult to figure out what’s going on in your stomach and which foods you’re reacting negatively to.

Registered dietitian Beth Czerwony, RD, LD, explains what fructans are, where they’re found and what to do if you think you have a fructan intolerance.

What’s a fructan intolerance?

Fructans are a type of oligosaccharides, which are part of a class of small-chain carbohydrates or sugars known as FODMAPs. That acronym stands for “fermentable oligosaccharides, disaccharides, monosaccharides and polyols” — but the much simpler FODMAPs will do just fine.

Not sure what, exactly, that means? Czerwony helps simplify: “There are naturally forming sugars in certain foods, and they all have their own unique sugar content and makeup.”

Importantly, FODMAPs are found across a wide spectrum of foods, and our bodies can’t digest them very well. But some people react worse to them than others do, experiencing symptoms like:

Foods high in fructans

OK, buckle up: A lot of foods have fructans in them. They can be broken down into two categories: Foods that have gluten in them and foods that don’t. In the typical American diet, the two biggest sources of fructans are wheat (which has gluten) and onions (which don’t). But there are lots of others that fall into these categories, too.

In the “has gluten” column are any typical bread products, including bread itself, along with pastries, pizza dough and so on. High-fructan foods that have gluten in them include:

  • Wheat.
  • Barley.
  • Rye.
  • Spelt.

On the other hand are high-fructan foods that don’t have gluten in them. That list is pretty long:

  • Fruits: Bananas, dates, grapefruit, nectarines, persimmons, plums, pomegranate, watermelon and yacon.
  • Legumes: Black beans,chickpeas, kidney beans, lima beans, mung beans, navy beans, split peas.
  • Vegetables: Artichoke, asparagus, beets, Brussels sprouts, chicory root, fennel, garlic, leeks, onions, savoy cabbage, shallots and snow peas.
  • Nuts: Almonds, cashews and pistachios.

Advertisement

“A lot of these foods are ones that we default to because they’re healthy options,” Czerwony notes. “Depending on how your body reacts to them, you may have to figure out what your personal limit is.”

Should you avoid eating fructans?

Foods that contain fructans are part of a healthy, balanced diet, so if you don’t have a fructan intolerance, there’s no reason to avoid them.

But what if you don’t yet know?

If you’re prone to gas, bloating and overall stomach issues without any clear cause, start paying attention to how certain foods make you feel.

“Keep a food log where you track what you eat and what’s going on in your body afterward,” Czerwony suggests. “You may start to see when your symptoms occur, which will help you figure out if you should be eliminating certain foods from your diet.”

What to do if you think you have a fructan intolerance

So, you suspect that you have a fructan intolerance. Now what? The only way to nail down a fructan intolerance is to go through a very specific elimination diet known as the low-FODMAP diet.

Advertisement

“You actually have to go through the list of each type of FODMAP and start eliminating foods that include them,” Czerwony explains. “If you find that you’re particularly sensitive to something, you’ll begin to slowly add certain foods back in to see like what your tolerance is — or if you can’t tolerate them at all.”

Because that’s the other thing: You can be levels of fructan intolerant. You could discover that you’re able to eat a little bit of some foods that contain fructans but that a super-oniony meal is too much for you to handle. Or maybe it all upsets your stomach. But you can’t know for sure until you’ve done the low-FODMAP diet.

“There may be foods that you end up totally eliminating from your diet, or you may find that you have some threshold of tolerance,” Czerwony notes.

Ask for help with the low-FODMAP diet

Working your way through any elimination diet can be a fairly involved process, and the low-FODMAP diet is especially in-depth. You want to make sure you’re doing it properly and that you’re still getting enough nutrients, especially as you remove so many foods from your diet.

Working with a dietitian will help you navigate it much more easily. They can also make the whole process a little bit less grueling by helping you figure out what you can eat — which is just an important as knowing what to stay away from.

“There are definitely foods that we’ll tell you to avoid, but we can also tell you what to replace them with so that you don’t feel like you can’t eat anything,” Czerwony reassures. “A dietitian is able to give you appropriate recommendations and alternatives based on your food preferences, too so that you’re still getting a well-balanced intake.”

Advertisement

Learn more about our editorial process.

Related Articles

Arm covered in hives
July 15, 2024/Skin Care & Beauty
Can Certain Foods Trigger or Prevent Chronic Hives?

Rarely are the red, itchy welts from chronic hives connected to what you eat

Person in an apron, kitchen carrying a loaf of sour dough bread on tray
July 12, 2024/Nutrition
Is Sourdough Bread Healthy for You?

Sourdough can be healthier than some other bread choices — but that doesn’t give it ‘health food’ status

Bowl of horseradish
July 8, 2024/Nutrition
4 Health Benefits of Horseradish

This spicy root helps fight cancer, bacteria and inflammation

An array of meatless foods in different vessels on table
July 5, 2024/Nutrition
Going Vegan 101: A Beginner’s Guide

The meatless, plant-based eating style has countless tasty and healthy options

Happy, smiling child running amidst floating snacks
July 5, 2024/Nutrition
Sugar: How Bad Are Sweets for Your Kids?

Too much added sugar early in life is linked to obesity, high blood pressure and Type 2 diabetes

Hands cupping bowl of greens, chickpeas, whole figs, halved and tofu
July 3, 2024/Nutrition
4 Health Benefits of Figs

Packed with fiber and nutrients, this flower — yep, flower! — is great for your blood sugar, heart and gut

Assorted whole-grain foods, fruits, vegetables and nuts
June 21, 2024/Nutrition
Eating for Energy: Foods That Fight Fatigue

What’s on your plate can either help power you through your day or put you in nap mode

Person standing in front of oversized nutrition label, reading it
June 19, 2024/Nutrition
What Can You Learn From a Nutrition Label?

Information on serving size, calories and nutrients can help you make healthy choices

Trending Topics

Female and friend jogging outside
How To Increase Your Metabolism for Weight Loss

Focus on your body’s metabolic set point by eating healthy foods, making exercise a part of your routine and reducing stress

stovetop with stainless steel cookware and glassware
5 Ways Forever Chemicals (PFAS) May Affect Your Health

PFAS chemicals may make life easier — but they aren’t always so easy on the human body

jar of rice water and brush, with rice scattered around table
Could Rice Water Be the Secret To Healthier Hair?

While there’s little risk in trying this hair care treatment, there isn’t much science to back up the claims

Ad