Gluten, a protein found in specific grains, can be problematic for individuals with certain health conditions. Navigating a gluten-free diet requires a thorough understanding of what foods contain gluten. This guide provides an in-depth look at gluten-containing foods, helping you make informed dietary choices for better health.
Understanding Gluten and Why It Matters
Gluten is a protein composite that provides elasticity to dough, giving bread its chewy texture. It is primarily found in wheat, rye, barley, and triticale, a hybrid of wheat and rye. While harmless for most, gluten can trigger adverse reactions in individuals with conditions like celiac disease, non-celiac gluten sensitivity, wheat allergy, and gluten ataxia.
For those with celiac disease, consuming gluten initiates an autoimmune response that damages the small intestine, hindering nutrient absorption and leading to various health issues. Non-celiac gluten sensitivity causes similar symptoms but without the intestinal damage. Wheat allergy involves an immune response to wheat proteins, not just gluten, while gluten ataxia affects nerve tissues, impacting coordination. In all these cases, avoiding gluten is crucial for managing symptoms and preventing complications.
Core Gluten-Containing Grains to Avoid
The cornerstone of a gluten-free diet is eliminating grains that naturally contain gluten. These include:
Wheat
Wheat is the most prevalent gluten-containing grain and comes in numerous forms, all of which must be avoided on a gluten-free diet. These include:
- Varieties of Wheat: Couscous, durum, einkorn, emmer, farro, graham, kamut, spelt, wheat berries, and semolina.
- Wheat Flours: All-purpose flour, enriched flour, farina, graham flour, self-rising flour, and wheat flour.
- Wheat Components: Wheat bran, wheat germ, and cracked wheat.
Barley
Barley is another grain high in gluten and is commonly found in:
- Barley Grain and Flour: Pearl barley, barley flakes, barley flour.
- Malt Products: Malt syrup, malt extract, malt flavoring, and malt vinegar (in some cases).
- Beer: Most beers are brewed with barley.
Rye
Rye is a grain closely related to wheat and barley and is also a source of gluten. Avoid:
- Rye Grain and Flour: Whole rye, rye flour, rye bread.
- Rye-based products: Pumpernickel bread, rye crackers.
Triticale
Triticale is a hybrid grain derived from wheat and rye, inheriting gluten from both parent grains.
Oats (Potentially)
Oats themselves are naturally gluten-free. However, they are frequently cross-contaminated with wheat, barley, or rye during farming, processing, and manufacturing.
- Non-Certified Gluten-Free Oats: Regular oats, oat flour, oat bran.
- Cross-Contamination Risk: Unless labeled gluten-free, assume oats are contaminated.
- Gluten-Free Oats: Certified gluten-free oats are processed to minimize cross-contamination and are safe for most gluten-free diets. However, a small percentage of people with celiac disease may still react to avenin, a protein in oats. Consult a healthcare professional about including gluten-free oats.
Surprising Foods That Often Contain Gluten
Beyond obvious grain sources, gluten lurks in many processed foods, often as a hidden ingredient. Careful label reading is essential.
Starchy Foods
- Breads: Most conventional breads, including white, wheat, sourdough, and multigrain, contain wheat flour. Gluten-free breads are available but must be specifically labeled.
- Pastas: Traditional pasta is made from wheat semolina. Gluten-free alternatives made from rice, corn, or bean flours are available.
- Cereals: Many breakfast cereals, especially those made from wheat, barley, or rye, contain gluten. Opt for certified gluten-free cereals.
- Crackers and Croutons: Wheat-based crackers and croutons are not gluten-free. Seek out gluten-free versions.
- Communion Wafers: Traditional communion wafers are made from wheat. Gluten-free options are available.
- Matzo: This unleavened bread is made from wheat.
- Seasoned Rice Mixes and Pilafs: Some pre-packaged rice mixes and pilafs contain gluten-based flavorings or pasta.
Processed Sweets and Snacks
- Cakes, Pies, and Cookies: Most commercially baked goods contain wheat flour unless specifically labeled gluten-free.
- Candies: Some candies, particularly chocolate bars or those with cookie crumbs, may contain gluten.
- French Fries: While potatoes are gluten-free, French fries can be cross-contaminated if fried in oil used for gluten-containing foods or if coated with a wheat-based batter.
- Seasoned Snack Foods: Flavored potato chips, tortilla chips, and other snack foods may contain gluten in seasonings or as a binding agent.
- Soups, Soup Bases, Broth, and Bouillon: Many canned soups, soup bases, and bouillon cubes contain wheat flour as a thickener.
Alcoholic Drinks and Related Products
- Beer, Ale, Porter, Stout: Most beers are brewed with barley and therefore contain gluten. Gluten-removed beers are available but may not be suitable for individuals with celiac disease.
- Malt and Malt Products: Malt flavoring, malt extract, and other malt products are derived from barley and contain gluten.
Processed Meats
- Burgers and Meatloaf: Breadcrumbs, often made from wheat, are frequently used as fillers in burgers and meatloaf.
- Hot Dogs and Sausages: Gluten can be used as a binder in hot dogs and sausages.
- Imitation Seafood: Surimi and other imitation seafood products may contain wheat starch.
- Processed Lunchmeats: Some deli meats contain gluten as a filler or binder.
Condiments
- Gravies: Many gravies are thickened with wheat flour.
- Salad Dressings: Creamy salad dressings and some vinaigrettes may contain gluten as a thickener or stabilizer.
- Sauces: Soy sauce traditionally contains wheat. Tamari soy sauce is often gluten-free, but check labels. Many other sauces, such as teriyaki sauce and Worcestershire sauce, may also contain gluten.
Hidden Sources of Gluten
Gluten can also be found in unexpected places:
Food Labels and “Hidden Gluten”
- Ingredient Lists: Always read ingredient lists carefully, looking for wheat, barley, rye, oats (unless certified gluten-free), malt, and other gluten-containing ingredients.
- “Natural Flavorings” and “Modified Food Starch”: These can sometimes be derived from wheat. If concerned, contact the manufacturer.
- Cross-Contamination: Be aware of cross-contamination risks, especially in restaurants and when using shared kitchen equipment.
Medications and Supplements
- Binding Agents: Some medications and dietary supplements use wheat gluten as a binding agent.
- Labeling: Medications and supplements containing wheat gluten must declare “wheat” on the label. Consult your pharmacist or healthcare professional if concerned.
Naturally Gluten-Free Foods: Safe Choices
Fortunately, many nutritious and delicious foods are naturally gluten-free, forming the basis of a healthy gluten-free diet:
- Fruits and Vegetables: Fresh fruits and vegetables are naturally gluten-free. Be cautious with processed, canned, or frozen versions, which may contain gluten-containing additives.
- Lean Proteins: Fresh meats, poultry, fish, eggs, legumes, nuts, and seeds are gluten-free in their unprocessed forms. Be mindful of marinades, seasonings, and breading.
- Dairy: Plain milk, plain yogurt, and most natural cheeses are gluten-free. Processed cheese products may contain gluten.
- Gluten-Free Grains: Amaranth, arrowroot, buckwheat, corn (including polenta and grits labeled gluten-free), flax, gluten-free flours (rice, soy, corn, potato, bean), hominy, millet, quinoa, rice (including wild rice), sorghum, soy, tapioca, and teff.
Conclusion
Identifying What Has Gluten In It is the first and most crucial step in following a gluten-free diet. By understanding the core gluten-containing grains, recognizing hidden gluten in processed foods, and focusing on naturally gluten-free options, you can effectively manage your diet and improve your health. Always prioritize reading food labels, asking questions when eating out, and choosing certified gluten-free products to ensure you are truly avoiding gluten and enjoying a safe and nutritious diet.
References
- ‘Gluten free’ means what it says. U.S. Food and Drug Administration. https://www.fda.gov/consumers/consumer-updates/gluten-free-means-what-it-says. Accessed Aug. 28, 2024.
- Label reading and the FDA. Celiac Disease Foundation. https://celiac.org/gluten-free-living/gluten-free-foods/label-reading-the-fda/. Accessed Aug. 28, 2024.
- Gluten-free diet: Nutritional value. American Gastroenterological Association. https://patient.gastro.org/gluten-free-nutritious-diet/. Accessed Aug. 28, 2024.
- Non-celiac gluten / wheat sensitivity. Celiac Disease Foundation. https://celiac.org/about-celiac-disease/related-conditions/non-celiac-wheat-gluten-sensitivity/. Accesed Aug. 28, 2024.
- Celiac disease and gluten intolerance. Office on Women’s Health. https://www.womenshealth.gov/healthy-eating/food-allergies-and-sensitivities/celiac-disease-and-gluten-intolerance. Accessed Aug. 28, 2024.
- Celiac disease nutrition therapy. Nutrition Care Manual. Academy of Nutrition and Dietetics. https://www.nutritioncaremanual.org. Accessed Aug. 28, 2024.
- What is celiac disease? Celiac Disease Foundation. https://celiac.org/about-celiac-disease/what-is-celiac-disease/. Accesed Aug. 28, 2024.
- Aljada B, et al. The gluten-free diet for celiac disease and beyond. Nutrients. 2021; doi:10.3390/nu13113993.
- Wheat. American College of Allergy, Asthma and Immunology. https://acaai.org/allergies/allergic-conditions/food/wheat-gluten/. Accessed Aug. 28, 2024.
- Gluten: Reading a label. American Gastroenterological Association. https://patient.gastro.org/gluten-free-label-reading/. Accessed Aug. 29, 2024.
- Gluten-free nutrition therapy. Nutrition Care Manual. Academy of Nutrition and Dietetics. https://www.nutritioncaremanual.org. Accessed Aug. 28, 2024.
- Ferri FF. Non-celiac gluten sensitivity. In: Ferri’s Clinical Advisor 2025. Elsevier; 2025. https://www.clinicalkey.com. Accessed Aug. 30, 2024.
- Niland B, et al. Health benefits and adverse effects of a gluten-free diet in non–celiac disease patients. Gastroenterology & Hepatology. 2018; https://pubmed.ncbi.nlm.nih.gov/31354988/. Accessed Aug. 30, 2024.
- Diez-Sampedro A, et al. A gluten-free diet, not an appropriate choice without a medical diagnosis. Journal of Nutrition and Metabolism. doi:10.1155/2019/2438934.
- Duyff RL. Cope with food allergies and other food sensitivies. In: Academy of Nutrition and Dietetics Complete Food and Nutrition Guide. 5th ed. Houghton Mifflin Harcourt; 2017.
- What is gluten? Celiac Disease Foundation. https://celiac.org/gluten-free-living/what-is-gluten/. Accessed Aug. 30, 2024.
- Bread, multi-grain (includes whole-grain). FoodData Central. https://fdc.nal.usda.gov/fdc-app.html#/food-details/168013/nutrients. Accessed Sept. 3, 2024.
- Zeratsky KA (expert opinion). Mayo Clinic. Sept. 4, 2024.
- Khanna S (expert opinion). Mayo Clinic. Sept. 12, 2024.
