Study Suggests that Self-Reported Celiac Disease Could Be Due to Another Molecule
Although medical statics show that celiac disease and gluten allergies are present in only a small number of people (less than 1%), a large number of people are claiming to suffer from celiac disease and reporting benefits from a gluten-free diet, even without a proper diagnosis. Perhaps, what is adding to the whole confusion is the vagueness in symptoms of non-gluten food intolerance.
Celiac disease is an autoimmune disease caused by gluten in particular cereals, mainly when wheat is rich in it. Abdominal pain, constipation, diarrhea, frequent bloating, and indigestion are common symptoms of celiac disease. But these symptoms are also persistent in a number of other ailments. Symptoms of bloating, flatulence, pain, distention, gas can be present in as many as one-third of adults.
Though celiac disease can be diagnosed with the help of various tests, there are still many self-diagnosed cases as well with people claim to feel the benefits from a gluten-free diet. The reason for such a benefit is that many of them are not aware of their intolerance to other food contents that are similar to gluten.
Fructan rather than gluten causes celiac-like symptoms
Though non-celiac gluten sensitivity is also a frequent phenomenon, it is difficult to diagnose due to the lack of specific tests or markers. It should be kept in mind that gluten-rich food is also rich in fructans, and other similar molecules are known to be poorly digested. Fructan is a kind of fermentable oligo-, di-, monosaccharides and polyols (FODMAP). Intolerance to fructans is one of the most common reasons for some to diagnose themselves with celiac disease.
To prove the concept, researchers recently carried out an study on 59 individuals on a gluten-free diet. These were people who thought that they had celiac disease, but weren't properly diagnosed by a professional and still received the benefits from a gluten-free diet. This test was a challenge for scientists, as they had to be very careful with how they would administer their experiment to their participants.
In the clinical trial, participants were randomly divided into groups and were given muesli bars that contained either gluten (5.7g) or fructan (2.1g) or a placebo. After seven days, they were allotted to another group until all of them have completed all the three challenges (gluten, fructan, and placebo). Their symptoms after each challenge were tested using a scale to measure whether or not they had irritable bowel syndrome.
The results of the test demonstrated that out of 59 almost half of them (24 to be precise) had severe symptoms of bowel irritation, and this was mainly those who ate the muesli bar containing, comparatively just nine complained of signs of bowel irritation in gluten group. Moreover, results of the gluten group were similar to the placebo group1.
This research clearly demonstrated that in cases of self-diagnosed gluten allergy, it could be other reasons to blame for symptoms. It is entirely possible that fructan is a more prominent culprit in indigestion, bloating and bowel discomfort as compared to gluten.
Understanding the fructan intolerance?
Geraminan, levanare, and inulin are some of the common structural forms of fructans found in food items. These are short-chain molecules made up of fructose and glucose combination. The reason for bloating, or abdominal distention, is the inability of our body to digest them completely. As per research, our body (small bowel) is capable of digesting and absorbing 5-15% of fructans. It is due to shortage of digestive enzymes; the situation is made worse also due to the smaller molecular mass of fructans resulting in higher water retention, abdominal distention, and pain2.
As per research in the mid-1990s, in the US average adult was consuming around 3.9g fructans a day, but in some individuals, it could be as high as 20g2.
Some of the food items known to be rich in fructan are wheat bread, pasta, garlic, onion, barley, cabbage, Brussels sprouts, pistachio, chickpeas.
It should be noted that these vague symptoms of bowel disturbances may also be caused due to galactans, lactose, and polyols. Humans have limited ability to digest them.
Is there a specific test to diagnose fructan intolerance?
No, there is no specific test that can diagnose the fructans intolerance with complete accuracy, though many breath tests are available which may indicate the possibility.
How to manage this new type of intolerance?
It is thought that as many as one-fourth of people with irritable bowel syndrome may have fructan intolerance. One of the proposed and tested ways is to switch onto the low FODMAP (Fermentable Oligosaccharides, Disaccharides, Monosaccharides, and Polyols) diet3.
It does not mean to avoid FODMAPs altogether, but instead, decrease their content in the diet. We are able to digest FODMAPs, but the individual variance is enormous.
So the kind of foods to eat less are:
- Lactose- milk and milk products like cheese, ice-creams
- Fructose- apples, peaches, pears, mangoes, cherries and watermelon, sweeteners and food items with corn syrup
- Fructans- Brussels sprouts, chickpeas, kidney beans, beetroot, garlic, wheat (bread, pasta)
- Polyols- apples, blackberries, cherries, apricots, peaches, plums, watermelon, and many artificial sweeteners
On the other hand, eat more of foods low in FODMAPs4:
- Fruits- oranges, strawberries, lemon, and lime, cranberries
- Vegetables- cucumber, turnip, sprouts, green beans, lettuce, spinach, carrots, celery, peas
- Diary- lactose-free milk and products like cheese
- Meats/protein rich- Any type of unprocessed meat, peanut butter, eggs, tofu, almonds, walnuts
- Grains- rice, corn, oats, quinoa or buckwheat, popcorn, potato, grits
A non-gluten allergy is a huge group with the varied clinical picture, most of them are difficult to diagnose due to lack of any specific test. Hence one of the best ways is to make dietary changes. One such change could be to give a low FODMAP diet a try. It is vital to understand that humans have the ability to digest foods rich in FODMAPs, and many of those food items are highly nutritious. Hence, the recommendation is not about complete avoidance, but somewhat decreasing their consumption5.
References
1. Skodje GI, Sarna VK, Minelle IH, et al. Fructan, Rather Than Gluten, Induces Symptoms in Patients With Self-reported Non-celiac Gluten Sensitivity. Gastroenterology. 2017;0(0). doi:10.1053/j.gastro.2017.10.040.
2. Fedewa A, Rao SSC. Dietary fructose intolerance, fructan intolerance and FODMAPs. Curr Gastroenterol Rep. 2014;16(1):370. doi:10.1007/s11894-013-0370-0.
3. Biesiekierski JR, Peters SL, Newnham ED, Rosella O, Muir JG, Gibson PR. No Effects of Gluten in Patients With Self-Reported Non-Celiac Gluten Sensitivity After Dietary Reduction of Fermentable, Poorly Absorbed, Short-Chain Carbohydrates. Gastroenterology. 2013;145(2):320-328.e3. doi:10.1053/j.gastro.2013.04.051.
4. Harvard Health. Try a FODMAPs diet to manage irritable bowel syndrome. Harvard Health. https://www.health.harvard.edu/diet-and-weight-loss/a-new-diet-to-manage-irritable-bowel-syndrome. Published October 2014. Accessed December 3, 2017.
5. Mansueto P, Seidita A, D’Alcamo A, Carroccio A. Non-Celiac Gluten Sensitivity: Literature Review. J Am Coll Nutr. 2014;33(1):39-54. doi:10.1080/07315724.2014.869996.
