Gluten-free used to be pretty black-or-white: either you had celiac disease and needed a gluten-free diet, or you didn’t. Now, though, there’s a whole lot of gray area, and it can make for some pretty confusing health advice.
Part of the confusion lies in the difference between celiac disease (a diagnosable autoimmune condition involving physical damage to the lining of the intestines as a result of ingesting gluten) and the more mysterious phenomenon vaguely termed “gluten sensitivity.” Gluten sensitivity does not involve changes in intestinal lining or permeability and therefore may produce normal intestinal biopsy results when a person is tested for celiac disease. Gluten sensitivity is only established if celiac disease has been ruled out but symptoms seem to improve on a gluten-free diet.
Does gluten sensitivity actually exist, though?
New research seems to say it may not. A 2013 study reviewing gluten sensitivity in non-celiac irritable bowel syndrome (IBS) patients found improvement of symptoms not upon removing gluten from the diet, but by reducing the amount of FODMAPs the participants consumed.
Ok, let’s backtrack. FODMAPs are fermentable oligosaccharides, disaccharides, monosaccharides, and polyols, and they are the wrench in this gluten sensitivity equation. FODMAPs are carbohydrates that are often insufficiently digested in the intestine, making them prime food for gut bacteria. When gut bacteria “eat” (break down) compounds in our intestines, we may very well experience cramping, abdominal distention (bloating), and diarrhea. Do you know what those symptoms also describe? Yup: non-celiac gluten sensitivity.
Is it possible that the majority of individuals who seem to have a sensitivity to gluten are actually responding to high levels of FODMAPs in their diets? In short, yes, it’s possible, but everyone is a little different. Wheat, barley, and rye (the three gluten-containing grains to avoid) also happen to be high in FODMAPs, so feeling relief after eliminating these foods doesn’t say for sure whether it was the gluten or the FODMAPs causing the issue. More and more, scientists are considering wheat intolerance (as a result of FODMAP content) to be a more accurate explanation for this particular set of symptoms than gluten itself.
Wheat, barley, and rye are not the only foods high in FODMAPs; in fact, certain individuals who experience some relief by going gluten-free don’t find that it completely eliminates their symptoms. Total symptom relief often comes by looking at high-FODMAP foods in general. These foods fall into a few categories: foods with excess fructose (honey, apples, mango, watermelon, pear, and the vilified high-fructose corn syrup), fructans (artichokes, garlic, leek, onion, scallions, shallots, wheat, rye, barley, and inulin, which is found added to many packaged foods), lactose (milk and yogurt products), galacto-oligosaccharides (legumes, lentils, chickpeas), and polyols (apples, apricots, nectarines, pears, plums, prunes, mushrooms, and sugar alcohols like sorbitol and xylitol). Foods are constantly being tested and retested for FODMAP content, so this list should only be considered partial.
There is a way to tell if your gastrointestinal symptoms are related to gluten or these poorly absorbed carbohydrates known as FODMAPs. The first step is to find a gastrointestinal (GI) doctor you trust. Rule out actual celiac disease and wheat allergies (you must continue to consume gluten while testing for celiac or the results will be inaccurate), lactose intolerance, and a lesser-discussed condition called small intestine bacterial overgrowth, or SIBO for short. Once those are all excluded, find a registered dietitian, because this next part can be a bit of a pain.
You see, to test for FODMAP sensitivity, you have to do what’s called an elimination diet. Working closely with a dietitian, you will remove all sources of FODMAPs for up to six weeks to see if symptoms improve. Then, the dietitian will guide you through reintroducing the FODMAPs, group by group (fructose, fructans, lactose, galacto-oligosaccharides, and polyols, as mentioned above). The initial phase of the diet is highly restrictive, but the goal is to discover which specific groups of FODMAPs are causing you discomfort and in what quantities—in other words, to ultimately create as liberal a diet as possible without symptoms developing.
The gut is a fascinatingly mysterious set of organs, capable of much more than we fully realize. There is a solid chance that non-celiac gluten sensitivity either doesn’t exist or, at the very least, is considerably rarer than it seems. But that does not make your individual symptoms less real. If you feel as though something in your body is not right, find a doctor who takes your concerns seriously and explore all possible explanations.
It might be gluten, but it may be something else entirely. Don’t stop searching for answers, and don’t underestimate the power of those poorly digested, fermentable carbohydrates called FODMAPs. I think we’ll be hearing a lot more about them moving forward.