What is gluten, and is it our diet's latest nemesis?
You’ve read anecdotal tales of gluten-free diets improving athletic performance. Gluten-free products litter the shelves of health food stores and sales of these foods were well over $2 billion last year. Due in part to emerging research on the topic and, more likely, to the food industry’s excitement over the potential to create and sell even more processed foods, gluten-free diets have been touted for their health benefits as more and more decide to give up foods containing gluten. With all of this media attention, it can be difficult though to distinguish fact from fad. Is gluten a real health concern or just the latest trend for the nutrition-obsessed?
As a health practitioner I’ve been asked this question constantly over the past year, and find it’s best to start with the basics. Gluten is a general term for proteins found in wheat, barley, and rye. These proteins give breads their elasticity, chewiness, and structure (oh, and deliciousness!). Some people do not tolerate gluten, and this intolerance manifests itself in many ways, causing a wide array of diverse symptoms (and sometimes, hardly any symptoms at all.) To simplify the medical nonsense, it’s easiest to think of gluten sensitivities in three categories: gluten sensitive enteropathy (Celiac Disease), wheat allergy, and gluten sensitivity.
People with wheat allergies may be allergic to gluten or to other proteins found in wheat. This is one of the most common allergies, and is typically be diagnosed in early childhood. Wheat allergies present similarly to other food allergies, and may cause symptoms such as itching, swelling, hives, nausea, vomiting, and rarely, anaphylaxis, a severe reaction that can lead to death. Like other food allergies, an allergy to wheat can be detected and confirmed via blood or skin tests. Someone with a wheat allergy needs to, obviously, avoid any food containing wheat, but may be able to tolerate barley and rye.
Gluten Sensitive Enteropathy (GSE):
GSE, or Celiac Disease, is NOT a gluten allergy. Celiac Disease is actually an autoimmune disorder that can develop in either childhood or adulthood. Compared to a wheat allergy, in which the body creates antibodies in response to specific wheat proteins, gluten is toxic to the body, causing a destructive autoimmune response.
In Celiac Disease, ingesting gluten causes severe damage to the lining of the intestine, which can lead to malabsorption, long-term deficiencies, anemias, osteoporosis, and colon cancer. The illustration below from the Celiac Disease Center at Columbia University illustrates the damage to the villi of the small intestine caused by gluten in the Celiac patient:
Though awareness of Celiac Disease has increased significantly over the past several years, it can be difficult to detect because symptoms vary greatly and may include: diarrhea, fatty stools, neuropathy, poor balance, seizures, mouth ulcers, an itchy skin rash, bloating, indigestion, heart burn, and/or depression. At the same time, some people may be completely asymptomatic. Celiac Disease is one of the most prevalent autoimmune disorders, and is estimated in nearly 1% of the population. The disease can be diagnosed through blood test and biopsy, and there is no cure, so it’s crucial that diagnosed individuals follow a strict gluten-free diet, even if no symptoms are present.
In recent years there has been an emerging body of research surrounding non-Celiac gluten sensitivity. Symptoms are similar to those of Celiac Disease without the long-term damage to the small intestine. For this reason, people with gluten sensitivity may be able to tolerate gluten in small amounts. While there is currently no biomarker for gluten sensitivity and thus cannot be definitively diagnosed, experts estimate it may be prevalent in up to 6% of the general population.
So what does this mean to you? Essentially, if you don’t fall into one of these three categories there’s absolutely no need to follow a gluten-free diet. If you’re not gluten sensitive, there is no scientific evidence to support going gluten-free, and all myths about gluten-free diets “improving athletic performance” are purely anecdotal.
This is not to say that expert opinion will not change as the field progresses. Though we’ve subsisted off of wheat products for thousands of years, our methods of processing and cultivation have changed drastically, which, many people believe, may be associated with the growing prevalence of wheat protein sensitivity.
Of note, athletes with lower gastrointestinal distress upon exertion often attribute symptoms of Celiac Disease to being “part of the sport,” masking a serious diagnosis that has long-term implications for iron status, bowel, and bone health. If you suspect you may have Celiac Disease or gluten sensitivity, see a doctor who may also refer you to a registered dietitian to identify trigger foods. Because of the nature of our food system, almost all processed foods are contaminated with gluten, making a strict gluten-free diet very difficult to follow. Though plenty of substitute foods are available, they’re often more expensive and difficult to access, and foods containing gluten are generally valuable sources of carbohydrate, B vitamins, and fiber – all crucial building blocks of an athlete’s diet!
What’s the bottom line here? Don’t dump gluten unless you have to! And if you have to, or feel you might benefit physically or psychologically by doing so, look for the details in Part 2 of Going Gluten-Free.
Celiac Disease Center: http://www.celiacdiseasecenter.columbia.edu/A_Patients/A03-WhatAre.htm
Sapone A, et al. Divergence of gut permeability and mucosal immune gene expression in two gluten-associated conditions: celiac disease and gluten sensitivity. BMC Medicine. 2011;9(23). http://www.biomedcentral.com/1741-7015/9/23
Nestle, Marion. Gluten intolerance becoming more commonplace. San Francisco Chronicle. May 31, 2009. http://www.sfgate.com/cgi-bin/article.cgi?f=/c/a/2009/05/31/FDTT17NK4F.DTL
National Digestive Diseases Information Clearinghouse (NDDIC).Celiac Disease. http://digestive.niddk.nih.gov/ddiseases/pubs/celiac/#what
Beck, Melinda. Clues to Gluten Sensitivity.Wall Street Journal. March 15, 2011. http://online.wsj.com/article/SB10001424052748704893604576200393522456636.html
Brown AC. Gluten sensitivity: problems of an emerging condition separate from celiac disease. Expert Rev GastroenterolHepatol. 2012;6(1):43-55.