Foods That Have Gluten: A Comprehensive Guide

To manage a gluten-free diet, it’s essential to know which foods contain gluten. Understand what gluten is and identify foods to avoid for better health. By Mayo Clinic Staff

Gluten is a protein found in wheat, barley, rye, and triticale (a wheat-rye hybrid). It acts like a glue, helping foods maintain their shape and texture. While it’s a common component in many diets, gluten can pose health issues for some individuals. Understanding which foods have gluten is the first step in managing dietary needs for conditions like celiac disease, gluten intolerance, or wheat allergy.

Why Understanding Gluten in Foods Matters

For individuals with certain health conditions, avoiding gluten is not a lifestyle choice but a medical necessity.

Celiac Disease: A Serious Autoimmune Condition

Celiac disease is an autoimmune disorder where ingesting gluten triggers an immune response that damages the small intestine. This damage can lead to various digestive symptoms, including abdominal pain, bloating, and diarrhea. Beyond digestion, celiac disease can also manifest as fatigue, headaches, depression, and bone or joint pain. Over time, the damage to the small intestine impairs nutrient absorption, leading to deficiencies and other health complications.

Non-Celiac Gluten Sensitivity: Gluten Intolerance

Also known as non-celiac gluten sensitivity, gluten intolerance causes symptoms similar to celiac disease after consuming gluten, but without the same intestinal damage. The exact cause is still under investigation, and it might not be gluten itself but other components in gluten-containing foods, such as FODMAPs (fermentable oligosaccharides, disaccharides, monosaccharides, and polyols). Regardless of the precise mechanism, a gluten-free diet often alleviates symptoms for those with gluten intolerance.

Gluten Ataxia: Neurological Impact of Gluten

Gluten ataxia is another autoimmune condition associated with gluten intake, often co-occurring with celiac disease. It affects nerve tissues, particularly those controlling muscle movement, balance, and coordination. Research indicates that a gluten-free diet can help manage and reduce the symptoms of gluten ataxia.

Wheat Allergy: An Immune Response to Wheat Proteins

A wheat allergy is an immune system reaction to wheat proteins, including gluten. It can cause digestive symptoms similar to celiac disease or gluten intolerance, but may also include other allergic reactions like hives. While a wheat allergy necessitates avoiding wheat, it doesn’t always require eliminating other gluten-containing grains like barley and rye unless cross-contamination is a concern. Opting for gluten-free foods is generally beneficial for those with wheat allergies as these products are wheat-free.

Beyond these conditions, some individuals adopt a gluten-free diet believing it offers general health benefits, weight loss, or increased energy. However, scientific evidence supporting these claims for people without gluten-related disorders is still limited and requires further research.

Identifying Foods That Contain Gluten

Navigating a gluten-free diet requires careful attention to food choices, ingredients, and nutritional content. It’s crucial to know which food groups commonly contain gluten.

Grains to Avoid: Primary Sources of Gluten

The most significant sources of gluten are specific grains and their derivatives. These grains must be avoided in a gluten-free diet:

Wheat: This includes all forms of wheat, such as:
- Wheat Berries
- Durum
- Einkorn
- Emmer
- Farro
- Graham
- Kamut
- Spelt
- Semolina
- Wheat Germ
- Wheat Bran
- Couscous
Barley: Often found in malt products, soups, and some processed foods.
Rye: Used in rye bread and some crackers and cereals.
Triticale: A hybrid of wheat and rye, inherently containing gluten.
Oats (Potentially): While oats themselves are gluten-free, they are frequently processed in facilities that also handle wheat, barley, and rye. This leads to cross-contamination. Only oats specifically labeled “gluten-free” are considered safe, but even then, some individuals with celiac disease may react to avenin, a protein in oats. Consult a healthcare professional about including even gluten-free labeled oats in your diet.

Wheat Varieties and Flours: Hidden Gluten Sources

Many terms related to wheat indicate the presence of gluten. Be aware of these wheat varieties and flours:

Wheat Varieties: As listed previously (Durum, Spelt, etc.).
Wheat Flours: All wheat-based flours contain gluten, including:
- Enriched Flour: Wheat flour with added vitamins and minerals.
- Farina: Milled wheat used in hot cereals.
- Graham Flour: Coarse whole-wheat flour.
- Self-Rising Flour (Phosphate Flour): Contains added leavening agents.
- Semolina: Used in pasta and couscous.

Processed Foods: Where Gluten Often Lurks

Processed foods require careful label reading because gluten can be a hidden ingredient. Always check ingredient lists for wheat, barley, rye, malt, and brewer’s yeast. In the U.S., the Food and Drug Administration (FDA) requires that foods labeled “gluten-free” contain less than 20 parts per million (ppm) of gluten.

Here are categories of processed foods that commonly contain gluten:

Starchy Foods:
- Breads (unless specifically gluten-free)
- Pasta (traditional wheat pasta)
- Cereals (many breakfast cereals)
- Crackers (non-gluten-free varieties)
- Communion Wafers
- Croutons
- Matzo
- Seasoned Rice Mixes and Pilafs
Sweets and Snacks:
- Cakes and Pies (most traditional recipes)
- Cookies (non-gluten-free types)
- Candies (some may contain gluten as a filler or binder)
- French Fries (may be cross-contaminated or contain wheat flour coating)
- Seasoned Snack Foods (flavored chips, pretzels – check labels)
- Soups, Soup Bases, Broth, Bouillon, and Soup Mixes (often use wheat flour as a thickener)
Beverages:
- Beer, Ale, Porter, Stout (traditionally made with barley)
- Malt Beverages and Malt Extracts
Processed Meats:
- Burgers (fillers may contain gluten)
- Hot Dogs (fillers may contain gluten)
- Imitation Seafood (often contains wheat-based binders)
- Meat Loaf (breadcrumbs often used as a binder)
- Processed Lunchmeats (may contain gluten as a filler)
- Sausage (fillers may contain gluten)
Condiments and Sauces:
- Gravies (often thickened with wheat flour)
- Salad Dressings (some creamy dressings)
- Sauces, including Soy Sauce (traditional soy sauce contains wheat)
Medications and Supplements:
- Some medications and dietary supplements use wheat gluten as a binding agent. Always consult with a pharmacist or healthcare provider about gluten content in medications and supplements.

Naturally Gluten-Free Foods: Safe Choices

Many whole foods are naturally gluten-free and form the foundation of a healthy gluten-free diet:

Fruits and Vegetables: Fresh fruits and vegetables are naturally gluten-free. However, be cautious with processed versions (canned, frozen with sauces, dried) as they may contain gluten-based additives.
Beans, Seeds, Legumes, and Nuts: In their natural, unprocessed forms, these are gluten-free. Be wary of seasoned or coated varieties.
Eggs: Naturally gluten-free.
Lean, Non-processed Meats, Fish, and Poultry: Fresh, unseasoned meats, fish, and poultry are gluten-free. Avoid breaded, marinated, or pre-seasoned options.
Most Low-Fat Dairy Products: Plain milk, plain yogurt, and unprocessed cheese are generally gluten-free. Check labels on flavored or processed dairy products.
Gluten-Free Grains, Starches, and Flours:
- Amaranth
- Arrowroot
- Buckwheat
- Corn (including cornmeal, grits, and polenta labeled gluten-free)
- Flax
- Gluten-free flours (rice, soy, corn, potato, bean flours)
- Hominy (corn)
- Millet
- Quinoa
- Rice (including wild rice)
- Sorghum
- Soy
- Tapioca (cassava root)
- Teff

Gluten-Free Labeling: What to Look For

Understanding gluten-free labels is crucial for safely navigating grocery shopping. In the United States, “gluten-free” labels indicate the product contains less than 20 ppm of gluten. These labels can appear on:

Naturally Gluten-Free Foods: Foods that are inherently gluten-free.
Prepared Foods Without Gluten Ingredients: Foods made without any gluten-containing ingredients.
Foods Processed to Remove Gluten: Foods that originally contained gluten but have been processed to reduce gluten levels below 20 ppm.
Foods Prevented from Cross-Contamination: Foods produced in environments that prevent gluten cross-contamination.

For alcoholic beverages, naturally gluten-free drinks like wine, distilled liquor (from non-grain sources), and gluten-free cider can be labeled as gluten-free. Beer and malt beverages made with barley are not gluten-free unless specifically processed and labeled as “gluten-removed” (note that “gluten-removed” beers are still not recommended for individuals with celiac disease due to potential residual gluten content and testing limitations).

Practical Tips for Avoiding Gluten

Maintaining a gluten-free lifestyle, especially for conditions like celiac disease, requires vigilance both at home and when eating out.

At Home:

Separate Storage: Store gluten-free foods separately from gluten-containing foods to prevent cross-contamination.
Clean Surfaces and Utensils: Thoroughly clean cooking surfaces, utensils, and storage areas.
Dedicated Equipment: Consider using separate cutting boards, toasters, and cooking equipment for gluten-free food preparation.
Careful Dishwashing: Ensure dishes and cooking equipment are washed thoroughly.

Eating Out:

Research Menus Online: Check restaurant menus online beforehand to identify gluten-free options.
Dine at Off-Peak Hours: Eating early or late allows restaurants to be more attentive to dietary needs.
Communicate with Servers: Clearly communicate your gluten-free requirements to your server.
Inquire About Preparation: Ask about ingredients, preparation methods, and cross-contamination precautions. Request food to be prepared using clean equipment and surfaces.

Potential Downsides of a Gluten-Free Diet

While necessary for certain individuals, a gluten-free diet can have nutritional and economic considerations.

Nutritional Risks:

Gluten-containing foods, especially whole grains, are sources of essential nutrients like iron, fiber, calcium, thiamin, riboflavin, niacin, and folate. Eliminating these foods requires careful attention to nutrient intake. Gluten-free replacement products may not always be nutritionally equivalent and can sometimes be higher in fat and sugar. It’s important to:

Read Labels Carefully: Check gluten-free product labels for nutrient content, sodium, sugar, and fat.
Consult Professionals: Work with a healthcare professional or registered dietitian to ensure adequate nutrient intake on a gluten-free diet. They can recommend gluten-free sources of these vital nutrients and advise on supplementation if needed.

Cost Considerations:

Gluten-free products are often more expensive than their gluten-containing counterparts. This can create a significant financial burden, especially for those relying heavily on processed gluten-free foods. Focusing on naturally gluten-free whole foods can help manage costs while maintaining a healthy diet.

Conclusion: Navigating Gluten-Free Living

Understanding which foods have gluten is crucial for managing conditions like celiac disease, gluten intolerance, and wheat allergy. While adopting a gluten-free diet can be challenging, especially in identifying hidden gluten sources, it is manageable with careful planning, label reading, and awareness of food preparation practices. By focusing on naturally gluten-free foods and being informed about processed foods, individuals can successfully maintain a healthy and fulfilling gluten-free lifestyle. For those without diagnosed gluten-related disorders, the claimed benefits of a gluten-free diet lack robust scientific backing, and it’s essential to consider potential nutritional imbalances and costs before making dietary changes. Always consult with healthcare professionals for personalized dietary advice.

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