Hidden Sources of Gluten

Woman reading food label

If you have celiac disease or are gluten intolerant, it's important to avoid gluten, even when it is hidden in trace amounts in food. Your degree of sensitivity will determine the importance of this issue. For many individuals, living a gluten-free lifestyle is not a choice, but an absolute necessity.

Avoiding Gluten

Gluten is not a grain itself, but rather a protein that is a component of wheat, rye, and barley. It is the agent which gives gluten-containing flours their distinctive elasticity. On the surface, it may seem easy to avoid gluten by steering clear of anything containing wheat, rye, or barley. However, bread and whole grain products are not the only uses for these grains. Gluten is found in many commercial products under several misleading names.

This aspect of living a gluten-free lifestyle can make it so difficult at times for gluten-sensitive individuals. With some foods, it simply isn't obvious whether there is gluten present, making it one of the more vexing traits of the substance.

Gluten in Non-Food Products

Many non-food products you use may contain gluten. While you don't consume these products, they may enter your body through the skin or inhalation.

Supplements and Medications

Many vitamins, minerals, and herbal supplements contain gluten. For example, one study found gluten in nearly 24 percent of the supplements it tested.

Seek supplements that are labeled as gluten-free. Many brands, such as GNC and Source Naturals, offer gluten-free vitamins, minerals, and herbal preparations. A few supplements to watch out for that do contain gluten include:

  • One-A-Day cannot guarantee their supplements are gluten-free.
  • Flintstones Vitamins cannot guarantee any of their products are gluten-free. However, if wheat is added, they do note this on the label.
  • NatureMade supplements may contain gluten, but it is indicated on the label.

Binders, flavoring agents, and other ingredients in prescription and over-the-counter medications may contain gluten, according to the National Foundation for Celiac Awareness. The foundation also cautions that generic medications and name-brand medications may contain different ingredients, so reading those labels is essential. Talk to your pharmacist about your gluten intolerance and ask to read the labels of any and all medications.

Look for words in supplements and medication ingredients such as:

  • Wheat
  • Dextrin (if the source is not specified as corn or some non-gluten containing source)
  • Caramel coloring
  • Barley malt
  • Dextrimaltose
  • Dextrates (with a non-specified source)
  • Modified starch (with a non-specified source)
  • Pregelatinized starch (with a non-specified source)

Because manufacturers often change formulations of drugs and supplements, it's important to check regularly to ascertain those you take do not contain gluten. If you have any reaction after starting a new bottle of supplements, contact the manufacturer for updated information.

Beauty Products

Hand lotion

Some beauty products contain gluten. According to the Mayo Clinic, you can't absorb the gluten through your skin. However, if you use gluten products near your mouth (such as lipstick, lip balm, and lip gloss), you may swallow or ingest some gluten, which can be a problem.

Along with lipstick, you may accidentally ingest other cosmetic products. For example, if you use hand lotion and then eat, you may inadvertently ingest some gluten. Accidentally swallowing some water with gluten-containing shampoo, conditioner, or soap in the shower or when washing your hair or face can also cause issues. For this reason, it's best to avoid any cosmetics that may contain gluten. Look for ingredients such as:

  • Hydrolyzed wheat protein (or any ingredient using the word "wheat")
  • Wheat amino acids (or amino acids without a specified source)
  • Barley seed extract (or any ingredient using the word "barley")
  • Aspergillus
  • Avena (Avena are oats. While not all oats contain gluten, they are often processed in plants that do, so it's best to avoid any products containing any oats unless it is certified gluten-free.)
  • Dextrin or dextrose from a non-specified source
  • Hydrolyzed malt extract (or any ingredient containing the word "malt")
  • Hydrolyzed vegetable protein
  • Polygonum G
  • Secale cereale seed (or any ingredients that contain secale cereale seed)
  • Tocopherol acetate
  • Triticum aestivum
  • Triticum turgidum durum
  • Triticum vulgare
  • Bran
  • Yeast extract

If you are concerned about gluten in beauty products, you can email or contact the manufacturer and ask which products they offer that do not contain gluten. The Urban Tastebud has an extensive list of cosmetics that don't contain gluten. However, it's important to continue to monitor ingredients to ensure formulations haven't changed.


Some toothpaste brands contain gluten, as well. The following brands do not contain gluten and are safe for use:

  • Tom's of Maine never puts gluten in any of its products, including toothpaste.
  • Crest toothpaste is gluten-free; however, the company can't guarantee the gluten-free status of its Pro-Health rinse.
  • Colgate certifies that all of their toothpastes are gluten-free.


Some gums may contain gluten. Gum that may not be gluten free includes:

  • None of Hershey's brands of gum appear on their gluten-free list, including Bubble Yum and Ice Breakers
  • In the past, Mondelez International would not state any of their products are definitively gluten-free, so it's best to avoid branded gums, including Dentyne, Chiclets, Stride, and Bubblicious.

The following brands do not currently contain gluten, although it is always best to check with the manufacturer.

  • Wrigley says they label any products containing allergens including gluten.
  • Glee notes in their FAQ that their gum is gluten-free and safe for consumption by people with celiac disease or gluten intolerance.

Play Dough

Gluten-containing play dough

Many children's play dough products (including Play-Doh) contain gluten. This can be a problem since some children eat play dough, while others touch their mouth after playing with play dough and before washing.

It's best to make gluten-free play dough at home. The Celiac Disease Foundation has a great play dough recipe for gluten sensitive kids. Talk to your children's school, daycare, or other places your kids play so they know your child cannot use regular play dough due to gluten sensitivities. It may help to provide play dough for playtime.

Gluten in Food

Foods may contain gluten if the ingredients used in the production process contain gluten. Due to the widespread use of flour, all baked goods potentially contain gluten. However, gluten's presence goes far beyond the bakery. Gluten is contained in a wide variety of common foods.

Ingredients to Avoid

Processed foods venture into a nebulous area of gluten-free and gluten unsafe. Some additives may contain gluten even if the main ingredient does not.

Artificial coloring, caramel color, modified food starches, and dextrin may all contain gluten depending upon how they were produced. Even seemingly innocuous ingredients, such as ground spices, baking powder, and vegetable broth may be gluten unsafe. The Gluten-Free Society offers a comprehensive list of gluten-containing ingredients and foods.

Surprising Foods That Contain Gluten

Some gluten-containing foods may surprise you. It's important to read labels carefully to look for any of the above ingredients. It's also important to realize that wheat-free on a label does not necessarily mean gluten-free, so you must look for other gluten-containing ingredients. The following foods often contain gluten.

  • Surimi: Also known as Krab or imitation crab meat, this food often contains flour, although Trans Ocean's Simply Surimi is gluten-free.
  • Mustard: Many brands of mustard contain wheat or flour as a thickener. Annie's Naturals and Grey Poupon are safe choices after reading the labels. If they do contain gluten, it is on the label.
  • Spices and spice blends: These may have gluten-containing fillers, such as wheat. You're best sticking with single spices and making blends. Read labels - if they contain 100 percent spice or herbs with no filler, they should be gluten-free.
  • Bouillion cubes: These cubes may contain gluten as a filler. HerbOx is gluten-free.
  • Soups: Many soups contain flour or roux as a thickener. For example, most of Campbell's cream soups (cream of mushroom, cream of celery, cream of chicken, etc.) contain gluten, but they have other soups that are gluten-free.
  • Stew: Most canned stews contain gluten because they are thickened with roux. Avoid canned stews unless they are specifically labeled gluten- free.
  • Candy: Many candies, such as Twizzlers and Whoppers, contain flour or other gluten products. However, most candy manufacturers, like Hershey's, do have gluten-free product lists.
  • Flavored chips: Many potato chips and corn chips may contain gluten in the flavoring, or they may be processed in plants that process gluten-containing foods. For example, some Ruffles flavored chips such as Cheddar and Sour Cream contain gluten. Check out Frito-Lay's list of gluten-free products.
  • Nut mixes: Some nut mixes may have spices and seasonings that contain gluten. Check manufacturer's ingredients and websites to determine which nuts are gluten-free.
  • Worcestershire sauce: Some brands contain gluten from malt vinegar. Lea & Perrins does not.
  • Deli meats: These pre-sliced meats may contain fillers or flavorings with gluten. Many store brands also contain gluten. Read labels carefully or check manufacturer websites. If it is labeled gluten-free, you can trust this is the case.
  • Meatballs, sausage, and hotdogs: These all may contain flour or breadcrumbs as a binder. Boards Head offers gluten-free lunch meats, sausages, and hotdogs.
  • Salad dressing: Salad dressings may contain an array of gluten-containing products such as mustard, soy sauce, and spice blends. Annie's Naturals makes an array of gluten-free salad dressings, or you can make salad dressing easily with oil, vinegar, and herbs.
  • Frozen potatoes: These may be processed in a plant that processes gluten-containing ingredients, or may contain gluten as fillers or spices. Ore Ida has over 30 potato products that are gluten-free.
  • Miso: Miso may be made from barley, so it's important to read the label.
  • Pudding: Pre-made pudding may contain gluten as a thickener. Read labels and look for puddings that thicken with cornstarch instead of flour.
  • Sauces: Read sauce labels carefully. Even tomato sauces may contain flour as a thickener as well as undesignated spice blends that may contain gluten.


Cross-contamination can easily make a gluten-free food unsafe. Simply using the same utensils to prepare both gluten-containing and gluten-free foods can contaminate the safe foods. For example, if you fry breaded chicken strips in oil and then use the same oil to fry French fries, you cannot eat the fries. Therefore, most fast food and restaurant French fries are off limits because they are very likely fried in the same oil that fries gluten-containing ingredients.

Cross-contamination is a risk if you are cooking at home or dining out. Unless the restaurant staff is specifically instructed, chances are you will encounter unsafe foods.

Minimizing the Risk of Cross Contamination

It's important that if you prepare gluten-containing products in your kitchen, you take steps to minimize risks of cross-contamination. Consider the following suggestions:

  • Keep gluten-free foods in separate cupboards and drawers than gluten containing foods. In the pantry, keep shelves for gluten-containing and gluten-free foods. Store the gluten-free foods in tightly sealed containers on shelves above the gluten-containing foods.
  • In the fridge and freezer, store gluten-free and gluten-containing foods separately.
  • Use different storage containers for gluten-free foods and store the containers away from containers used for gluten-containing foods. To differentiate, consider using different brands, shapes, or colors of containers for gluten and gluten-free foods, or label with a colored pen or strip of colored tape.
  • Maintain a section of your counter that is only used for preparing gluten-free foods and teach your family to never prepare gluten-containing foods in that area.
  • Wash counters and gluten-free dishes with a separate sponge than you use for those with gluten-free dishes.
  • Maintain separate toasters for gluten-containing and gluten-free breads.
  • Maintain separate dishes, cooking utensils, cutting boards, mixing bowls, and pots and pans for preparing gluten-containing foods and gluten-free foods, and store them separately. This is especially important with materials which have a permeable surface where trace amounts of gluten might hide. These materials include wood, plastic, and Teflon, as well as any other materials that may scratch easily. Label these items with a strip of colored tape for gluten-free so they don't get mixed up.
  • Knife blocks are often filled with crumbs. Therefore, keep two knife blocks for gluten-free use and gluten use, or keep a special knife just for gluten-free. Label it with a strip of colored tape.
  • Keep separate butter and other condiments (peanut butter, jam, mustard, mayonnaise, etc.) - anything in which you might stick a knife - for gluten and gluten-free. Alternatively, use squeeze bottles for all of these types of items and teach family members to never touch the tip of the squeeze bottle to their food as they dispense.

Identifying Unsafe Foods

Allergies to gluten are not the only medical condition restaurants, and manufacturers face. This fact has led many companies to publish nutritional information on their websites. If the information is not displayed, contact the company for further information.

Such inquiries are commonplace for many businesses. If there is a question of cross-contamination in the manufacturing process, most companies will be upfront about this possibility. This is likely a risk with any company which produces both gluten-free and gluten-containing foods.

Product Labeling

The Food Allergen Labeling and Consumer Protection Act of 2004 gave the U.S. Food and Drug Administration the directive to determine the standards for gluten-free labeling, finalizing the standard in 2013. The current standard is 20 parts per million (ppm). For highly sensitive individuals, consuming one or more products with this amount of gluten may cause a reaction.

Avoiding Gluten

You may find it safest to stick with naturally gluten-free foods such as fresh produce and lean meats. Research other products as necessary. Be your own advocate as you discover which products are best for you.

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Hidden Sources of Gluten