25 Foods You Didn't Know Contained Gluten

Gluten-free products, marketed as such, were unknown 20 years ago, but the gluten-free industry is set to reach an estimated $2.34 billion in sales by 2019 — more than double its 2014 level. What sets gluten-free foods apart from other culinary trends or diet fads is that they address a legitimate health concern that affects millions of people around the world.

Celiac disease is an autoimmune disorder that is triggered by the intake of gluten — a protein inherent in wheat, barley, and rye. The body responds by attacking the small intestine, which damages the nutrient-absorbing villi that line it. As a result, many people with celiac disease report bloating, diarrhea, gas, weight loss, or fatigue after consuming gluten. Long-term health conditions such as iron deficiency, osteoporosis, and even cancer may develop if celiac disease goes untreated.

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Celiac disease is also hereditary, but not all people have the same degree of gluten intolerance. Some people are "celiac lite," meaning that their blood "may or may not" contain the level of antibodies qualifying them as celiac, says Dr. Joseph Murray, a professor of medicine and consultant in gastroenterology and immunology at the Mayo Clinic in Rochester, Minnesota, but that they suffer from the same gastrointestinal symptoms.  Another group of people can be labeled as having "nonceliac gluten sensitivity," meaning they have the same symptoms but don't have a history of or genetic predisposition to celiac disease. 

With an indeterminate number of people either gluten-sensitive or celiac-lite, detecting the presence of this potentially troublesome protein in food is incredibly important. Unfortunately, it's not as simple as simply avoiding rye bread and pizza crust; gluten likes to hide in many unexpected places. Many of your favorite foods actually contain some type of wheat derivative, ranging from straight wheat flour to malt extract, malt vinegar, and even some kinds of soy sauce. This guide is meant to help you navigate the grocery aisles and avoid any foods that might upset your gut.