All Things Gluten: Celiac, Non-Celiac Gluten Sensitivity, Wheat Allergy, Fructan intolerance and More
Gluten - you've probably heard of it, especially if you've ever explored the concept of dietary restrictions or found yourself on “wellness” social media pages. In recent years, gluten has become a scapegoat for many digestive issues - but does it really deserve the blame?
Gluten is a protein structure naturally found in certain grains like wheat, barley, and rye. It's what gives dough its elasticity, helping baked goods rise and giving them that beloved chewy texture (1).
In certain conditions, like celiac disease, gluten can cause significant harm. However, what we more commonly see is gluten undeservingly taking the blame for digestive symptoms when it is something else entirely. Let’s break down the gluten and gluten-related conditions further.
Celiac Disease: When Gluten IS the Problem
Imagine the immune system treating an innocuous substance as if it was harmful. That's precisely what happens with celiac disease, an immune-mediated inflammatory condition of the small intestine. When individuals with celiac disease consume gluten, it triggers an immune reaction, leading to inflammation and damage to the lining of the small intestine. This can result in a slew of symptoms, from chronic diarrhea, bloating and weight loss to malabsorption of vital nutrients. While diarrhea is common with celiac disease, it is not always present.
Genetics plays a crucial role in celiac disease, with over 99% of affected individuals carrying specific HLA genes (1, 2).
These genes code for proteins that help the immune system distinguish between self and non-self, making certain individuals more susceptible to gluten-induced immune responses.
The prevalence of celiac disease varies globally, affecting approximately 1.4% of the population (1). However, for those with a family history of the disease, the risk significantly increases, with first-degree relatives facing a 7.5% chance of developing it (2).
Navigating Symptoms and Diagnosis
The symptoms of celiac disease can vary widely, ranging from gastrointestinal issues like chronic diarrhea, bloating, gas and abdominal distension to more manifestations such as neurological symptoms and infertility. Diagnosing celiac disease typically involves a combination of blood markers and upper endoscopy with duodenal biopsy to confirm mucosal damage.
It is very important to rule out celiac disease if someone believes they are reactive to gluten before removing gluten from your diet, as a gluten-free diet can lead to false negatives in testing.
Beyond Celiac: Exploring Other Gluten-Related Conditions
Wheat allergy
While celiac disease is perhaps the most well-known gluten-related disorder, it's not the only one. Individuals may also experience IgE-mediated wheat allergy, characterized by immediate allergic reactions to wheat proteins. This is most commonly seen in childhood and outgrown by adolescence and is relatively uncommon, affecting about 0.4 percent of children in the United States (3,4). The main differentiator between other gluten and gluten-related conditions is the time frame. In IgE wheat allergies, we expect the reaction minutes to two hours after ingestion. This is typically tested when suspected with skin-prick testing or wheat-specific IgE measures in the blood.
Non-Celiac Gluten Sensitivity
The most common condition we see people coming in with, either self-diagnosed or diagnosed from another provider, is non-celiac gluten sensitivity (NCGS). NCGS is the name for when someone is sensitive to gluten and has associated symptoms like bloating, abdominal pain, and potentially changes to their bowel movements, but does not have serologic or histologic evidence of celiac disease. In other words, blood tests and small intestine biopsies appear normal. The difficulty lies in the absence of reliable tests to differentiate individuals with true NGCS from those with irritable bowel syndrome (IBS) or other symptoms that are not specifically related to gluten, so many end up with this diagnosis as a “catch-all” for digestive symptoms that are not celiac (5).
In a study involving 37 subjects diagnosed with both NCGS and irritable bowel syndrome (IBS), randomly and blindly assigned to no-gluten, low-gluten, or high-gluten groups, only 8% of the subjects had true gluten-specific negative effects (6). This suggests that the majority of those diagnosed with "gluten sensitivity" weren't actually experiencing adverse symptoms caused by gluten.
If gluten is not the issue, what is? There are a variety of different reasons that could explain the benefit. For one, it could be the placebo effect of removing gluten from one’s diet. Another commonly overlooked cause is fructan intolerance.
Fructan Intolerance
Fructans, a type of carbohydrate found in grains and other various foods, can trigger symptoms similar to those of gluten intolerance.
The human body has a limited ability to break down these carbohydrates which makes them poorly absorbed in the small intestine. Consequently, they move through the intestines to the colon, where they are fermented by bacteria and draw water in, which can lead to bloating and diarrhea. Some have a deficiency in the enzyme that breaks down the fructans for absorption, leading to more fructans being delivered to the colon and worsening of the related gastrointestinal symptoms. While there's no standardized test for fructan intolerance, restricting fructan intake has shown promise in alleviating symptoms for individuals with gastrointestinal disorders (7). Notably, gluten-containing grains like wheat, rye, and barley are also rich sources of fructans. Therefore, individuals who eliminate gluten from their diet often inadvertently reduce their intake of fructans, which could be the primary reason they experience symptom relief. But, this also means that they may be avoiding gluten containing foods that are not causing their symptoms as well and unnecessarily restricting their diet.
Conclusion: Dispelling Myths and Addressing Concerns
Despite the growing popularity of gluten-free diets, it's essential to separate fact from fiction. For individuals without celiac disease or wheat allergy, avoiding gluten may do more harm than good, potentially leading to nutritional deficiencies.
One study even showed that people who avoided gluten had an increased risk of cardiovascular disease and weight gain (8).
In the ever-evolving landscape of dietary restrictions and food sensitivities, understanding the nuances of gluten-related disorders is key. Whether it's celiac disease, wheat allergy, or non-celiac gluten sensitivity, each condition presents its own challenges and considerations. By staying informed and seeking guidance from healthcare professionals, individuals can make empowered choices about their dietary habits and overall well-being.
Questions? Let us know below. We're happy to address them on our social media for everyone to benefit.
Citations:
Singh P, Arora A, Strand TA, et al. Global Prevalence of Celiac Disease: Systematic Review and Meta-analysis. Clin Gastroenterol Hepatol. 2018;16(6):823-836.e2. doi:10.1016/j.cgh.2017.06.037
Singh P, Arora S, Lal S, Strand TA, Makharia GK. Risk of Celiac Disease in the First- and Second-Degree Relatives of Patients With Celiac Disease: A Systematic Review and Meta-Analysis. Am J Gastroenterol. 2015;110(11):1539-1548. doi:10.1038/ajg.2015.296
Keet CA, Matsui EC, Dhillon G, Lenehan P, Paterakis M, Wood RA. The natural history of wheat allergy. Ann Allergy Asthma Immunol. 2009;102(5):410-415. doi:10.1016/S1081-1206(10)60513-3
Gupta RS, Springston EE, Warrier MR, et al. The prevalence, severity, and distribution of childhood food allergy in the United States. Pediatrics. 2011;128(1):e9-e17. doi:10.1542/peds.2011-0204
Husby S, Murray JA. Gluten sensitivity: celiac lite versus celiac like. J Pediatr. 2014;164(3):436-438. doi:10.1016/j.jpeds.2013.11.024
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):320-8.e83. doi:10.1053/j.gastro.2013.04.051
Fedewa A, Rao SS. Dietary fructose intolerance, fructan intolerance and FODMAPs. Curr Gastroenterol Rep. 2014;16(1):370. doi:10.1007/s11894-013-0370-0
Lebwohl B, Cao Y, Zong G, et al. Long term gluten consumption in adults without celiac disease and risk of coronary heart disease: prospective cohort study. BMJ. 2017;357:j1892. Published 2017 May 2. doi:10.1136/bmj.j1892
Disclaimer:
The information in this blog is not intended or implied to be a substitute for professional medical advice, diagnosis or treatment. All content, including text, graphics, images and information, contained on or available through this blog is for general information purposes only. Modrn med and Dr. Mary Pardee make no representation and assume no responsibility for the accuracy of information contained in or made available through this blog, and such information is subject to change without notice. This blog does not provide medical services, diagnosis or counsel. You are encouraged to confirm any information obtained from or through this email with other sources, and review all information regarding any medical condition or treatment with your physician. Never disregard professional medical advice or delay seeking medical treatment because of something you have read on or accessed through this information.
コメント