What is Gluten?

Gluten is a general name for the proteins found in wheat (wheatberries, durum, emmer, semolina, spelt, farina, farro, graham, KAMUT® khorasan wheat and einkorn), rye, barley and triticale – a cross between wheat and rye. Gluten helps foods maintain their shape, acting as a glue that holds food together. Gluten can be found in many types of foods, even ones that would not be expected.

The Big 3: Wheat, Barley, Rye

Wheat in a field with a faded sunset in the background.

Wheat

Wheat is commonly found in:

  • breads
  • baked goods
  • soups
  • pasta
  • cereals
  • sauces
  • salad dressings
  • roux
Barley in a sack being poured.

Barley

Barley is commonly found in:

  • malt (malted barley flour, malted milk and milkshakes, malt extract, malt syrup, malt flavoring, malt vinegar)
  • food coloring
  • soups
  • beer
  • Brewer’s Yeast
Green rye in a field with sunlight reflecting off of the stalks.

Rye

Rye is commonly found in:

  • rye bread, such as pumpernickel
  • rye beer
  • cereals

Other Grains

Cut bread on a cutting board with cutlery and wheat alongside of it.

Triticale

Triticale is a newer grain, specifically grown to have a similar quality as wheat, while being tolerant to a variety of growing conditions like rye. It can potentially be found in:

  • breads
  • pasta
  • cereals
A brown spoon with oats in it on a wooden table.

Oats

Oats can add diversity and offer many nutritional benefits to a gluten-free diet. The Celiac Disease Foundation’s medical experts recommend only oats labeled gluten-free as cross-contact may occur when oats are grown side-by-side with wheat, barley or rye.

Patients eating oats from any source may complain of symptoms. Oats have a protein called avenin that is similar to gluten. Some people with celiac disease have an immune response to avenin as well as to gluten.

Oats also contain other substances that may cause a reaction for some people with or without celiac disease. Reactions to fiber or fermentable carbohydrates in a product that contains oats are usually not immune reactions, but can cause discomfort.

It’s important that you only use oat products that are labeled gluten-free if you decide to eat oats. You should talk with your gastroenterologist and dietitian about whether you should include oats in your gluten-free diet.

Gluten-Free Labeling of Oats

In 2006, a growing and manufacturing process called the “Purity Protocol” was developed to produce gluten-free oats. This protocol outlines measures to prevent gluten-containing grains from being mixed in with gluten-free oats.

Mechanical and optical sorting methods have been developed more recently to “clean” oats that have been mixed with gluten-containing grains in the field or during harvesting and transport. Special equipment is used to sort the oats from gluten-containing grains based on differences in size, shape, color, density, texture and electrical conductivity.

Manufacturers who put a “gluten-free” label on products that contain oats are claiming that measures have been taken to make sure the product contains <20 ppm (parts per million) of gluten. This is done either by following a “Purity Protocol” or using mechanical and optical sorting methods.

Read the NASSCD Statement on Oats here

*Boston Children’s Hospital 1/26/2021.