What’s Really Going on with Gluten?

Bill Clinton is gluten-free, Gwyneth Paltrow is gluten-free, Russel Crowe is gluten-free, so does this mean you should go gluten-free? The prevalence of people opting to go gluten-free has dramatically increased over the past few years. The gluten-free diet, originally intended to manage specific medical conditions affecting 1% of the population, has turned into a dietary trend so popular that Jimmy Kimmel made a TV segment about it. This blog post focuses on what the gluten-free diet actually is, and if this diet choice is right for you.

What is gluten, really? Gluten is a protein found in barley, rye, oats, and wheat, as well as many processed foods, some medicines, and even envelopes. It has a “sticky” consistency, so it is literally like a glue. Certain conditions call for strict gluten restriction, specifically celiac disease and some allergies. Celiac disease is an autoimmune disorder where the ingestion of gluten causes an antibody response, leading to the destruction of small intestinal cells. Once gluten is completely eliminated the cells are able to regenerate, and the small intestine will heal. Symptoms vary, but common ones are gastrointestinal distress, chronic hives, anemia, and weight loss. It can be tested for with a blood test, but the best way to test for it is with a biopsy examining the small intestinal cells.

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Photo by Sarah Steinmetz

True allergies, which are accounted in about 1% of the Western population, trigger a different immune response than autoimmune diseases. Specifically, when your body senses a substance that it’s allergic to, called an “antigen”, it will trigger IgE antibodies to attack the antigen, which releases a chemical called histamine in the process. This causes itching, swelling, hives, and gastrointestinal symptoms. Wheat allergies mimic symptoms of untreated celiac disease, but without the destruction of the small intestinal cells. Symptoms of wheat allergy improve when wheat, specifically, is removed from the diet, so complete gluten removal is not necessary. Allergies can be diagnosed with testing performed by an Immunologist.

The people who report not feeling well after ingesting gluten but do not have celiac disease or a true allergy, are what is called “intolerant” to gluten; the diagnosis for this condition is non-celiac gluten Sensitivity (NCGS). People with NCGS often simultaneously have symptoms of irritable bowel syndrome (IBS), which affects 20% of the population and is characterized as abnormal gastrointestinal symptoms with no known cause. There is no long-term cure for NCGS and IBS, but research is showing that a short-term elimination diet, called the low-FODMAP diet, has been shown to reduce symptoms of both IBS and NCGS, while a gluten-free diet has been shown to be ineffective at reducing symptoms in a subset of individuals. The low-FODMAP diet is carefully administered by a dietitian, and eliminates all poorly absorbed, short-chain carbohydrates for six to eight weeks, and one by one a new food is re-introduced to see if symptoms are induced, in order to gauge what should be avoided long-term. The low-FODMAP diet is low in gluten because many of the foods that contain gluten also contain these poorly absorbed carbohydrates. Therefore, it is presumed that people with NCGS and IBS may not be reacting to the gluten, rather they are reacting to specific carbohydrates in gluten-containing foods.

If you think you have any of the above conditions, it is critical that you see a doctor and dietitian prior to removing gluten from your diet. If you don’t, then it can cause the doctor to misdiagnose you and lead to an incorrect dietary prescription. Elimination diets, such as strict gluten-free or a low-FODMAP diet, may lead to unnecessary food restriction resulting in nutrient deficiencies if they are not administered and monitored correctly. A dietitian is responsible for making sure this doesn’t happen, and is trained to maximize your diet quality despite certain restrictions.  Many people who go gluten-free do it because they think it’s “healthy”, but many gluten-free products have more fat, sugar, and calories than their gluten-containing counterparts. Although people in the media report weight loss and “feeling better” after eliminating gluten from the diet, it’s important to consider that one dietary adjustment may not be the cause. For example, maybe these people increased their exercise? Or they are eating less in general? Or they have started eating more fruits, vegetables, and whole grains instead refined grains? If a healthy diet is your main concern, then a dietitian will work with you to make the necessary lifestyle changes.

To answer the question from the introduction, it is up to your healthcare providers. As of now, there is only evidence to support a strict, gluten-free diet if you have celiac disease. For all other conditions, whether it is an allergy or a desire for weight loss, talk with your primary care provider and a dietitian, who if necessary, will help you adjust your diet safely and effectively.


BARRETT JS, GEARRY RB, MUIR JG, et al. Dietary poorly absorbed, short-chain carbohydrates increase delivery of water and fermentable substrates to the proximal colon. Aliment Pharmacol Ther. 2010;31(8):874-882.

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.e1-3.

De Giorgio R, Volta U, Gibson PR. Sensitivity to wheat, gluten and FODMAPs in IBS: Facts or fiction? Gut. 2016;65(1):169-178.

Ong DK, Mitchell SB, Barrett JS, et al. Manipulation of dietary short chain carbohydrates alters the pattern of gas production and genesis of symptoms in irritable bowel syndrome. J Gastroenterol Hepatol. 2010;25(8):1366-1373.

Quirce S, Boyano-Martinez T, Diaz-Perales A. Clinical presentation, allergens, and management of wheat allergy. Expert Rev Clin Immunol. 2016:1-10.


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Sarah Steinmetz

Sarah Steinmetz

Sarah Steinmetz is a registered dietitian nutritionist (RDN), and is in her final year of the combined Masters in Clinical Nutrition/Dietetic Internship at Rush University Medical Center. She holds a BS degree in Dietetics from the University of Illinois at Urbana Champaign, ILL! Past and current research projects include the implementation of a quasi-experimental Registered Dietitian-provided low-FODMAP diet intervention in which Sarah does the low-FODMAP counseling (under supervision), an epidemiological analysis of NHANES examining the association between pediatric asthma prevalence and Mediterranean diet accordance, and metabolically healthy obesity. She is also one of three student coordinators for National Nutrition Month at Rush. She completed a one-month staff relief in general pediatrics and is hoping to pursue a career in pediatrics, sports nutrition, and nutrition support, as well as continue her research with the low-FODMAP diet.
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1 Comment

  1. Melissa Prest on February 17, 2016 at 1:42 pm

    Great job Sarah! Well-researched information.