Gluten is a class of protein. In wheat, Gluten is made up of two main parts: GLIADIN proteins and GLUTENIN proteins. When it comes to allergies and food sensitivities, the majority of people react to the gliadin part (but some people react to the glutenin part instead or as well).
What types of foods contain gluten? Gluten comes from the grains wheat, rye, and barley. That’s it. Wheat, rye, and barley. For the most part, that just means:
- Foods made from wheat, rye, and barley flour, such as pasta, bread, cereal, crackers, cookies, cake, pretzels, croutons, pastries, etc.
- Whole grain dishes, like foods made with bulgur (another name for wheat: see below)
- Drinks or Condiments made from barley, wheat, or rye, such as beer, whiskey, many vodkas (which, these days, are often made from wheat), and malt vinegar.
Gluten is not usually in any other food groups like dairy, meat, or vegetable based foods unless they either use some kind of wheat, rye, or barley ingredient as an additive or are processed in a factory that also makes food with wheat, rye, or barley. In other words:
What about "glutinous rice"? Does that have gluten in it? No - glutinous rice is called that because it’s sticky, not because it has gluten in it (the word “gluten” comes from the latin word for “glue”). All whole rice is gluten free.
What is “Corn Gluten”? Corn gluten is a term used by the agricultural industry to describe a protein byproduct of corn processing. It’s commonly used as a filler in livestock feed or pet food. It is NOT true gluten, and contains neither gliadin or glutenin. Thus corn gluten is actually “gluten-free”. However, many people with gluten allergy or sensitivity will also react to corn, especially if they are HLA-DQ2 or HLA-DQ8 positive.
Do beans and lentils have gluten? Nope! Unless they have additives, beans and lentils are gluten free.
What about oats? It’s true - while oats are naturally gluten free, many brands of oats are processed in facilities that contain wheat and so they are frequently contaminated with gluten. Packages that say “Gluten Free Oats” have oats that have been grown in fields separate from gluten-containing grains, processed in separate facilities, and tested to make sure they are not otherwise contaminated.
What other (weird) stuff can have gluten in it? Because gluten is gluey it is sometimes used as a binder in medications and supplements, and it’s often added to cosmetics, hair care products, and play-dough. This is especially important with things that go on the lips (lip gloss, lipstick, etc) because you are more likely to ingest them, and with things like play-dough because children will touch this and then put their hands into their mouths.
Next time: The Hidden Sources of Gluten. Did you know that wheat itself has over 10 common names, and that gluten can be hidden in dozens of ingredients? Tune in next time for a list of the ingredients you should watch for when reading labels at the grocery store.
Further Reading and Resources: