Wheat has been confirmed to contain multiple proteins that trigger symptoms in people with celiac disease or gluten sensitivity.

Is there more than one kind of wheat?

Yes. Wheat may not always be as easy to identify by name as you might expect. There are several species of wheat, and over time people have refined those species into many different types and derivatives--often with different names. What's more, different types of wheat can contain different levels of protein. Since celiac disease and gluten sensitivity are widely accepted to be triggered by several specific proteins, including two found in wheat, some may claim that the lower protein varieties of wheat are "safe" for people with celiac disease. While it is true that sensitivity to triggering proteins can vary based on the individual, this does not mean some types of wheat should be considered safe for anyone with celiac disease, gluten sensitvity or any other aversion to wheat such as wheat allergy. Any amount of any triggering protein has the potential to cause a reaction in anyone with celiac disease or gluten sensitivity. Wheat is also a common allergen and has been classified by the United States Food and Drug Administration (FDA) as a "major food allergen," meaning that heightened labeling and compliance standards apply for foods made with wheat. Always use caution when ingesting or serving any product that contains wheat, and consult your doctor if you think you may have celiac disease, gluten sensitivity or an allergy to wheat.

The United States Department of Agriculture (USDA) has developed standards for wheat, which it defines as any grain that contains certain threshold amounts of common wheat (Triticum aestivum L.), club wheat (T. compactum Host.), or durum wheat (T. durum Desf.). While there are officially eight USDA classes of standardized wheat (Durum, Hard Red Spring, Hard Red Winter, Soft Red Winter, Hard White, Soft White, Unclassed and Mixed), only five of these are considered "major." (These should not be confused with the eight major food allergens as classified by the FDA, which include foods other than wheat.) Each has its own unique characteristics that help dictate the types of foods in which it is typically used:

Standardized Wheat Type % of US Production (approx.) Typical Uses
Hard Red Winter (HRW) 40% Bread Flour
Hard Red Spring (HRS) 20% Specialty Breads
Soft Red Winter (SRW) 15% - 20% Cakes / Cookies / Crackers
White 10% - 15% Noodles / Crackers / Cereal / White-Crusted Breads
Durum 3% - 5% Pasta

Source: USDA

Although standardized wheat accounts for much of the wheat found in the products sold in the United States, other more exotic types and derivatives of wheat also exist. While these may be less common and go by names that can make it hard to know they're actually wheat, each one still presents a risk to those with celiac disease or gluten sensitivity (or wheat allergy) if they are consumed. Some examples include einkorn, emmer (also known as farro), farina, graham, khorasan (sometimes identified as Kamut®), semolina and spelt. Triticale is a manmade hybrid of wheat and rye that has its own USDA standard--it is not included in the USDA standard for wheat (or rye).

Want to Know More?

About the USDA's classification of wheat ... Read the United States Standards for Wheat [PDF]
About the different species of wheat ... Take a look at its USDA Classification Report and profiles for common wheat and durum wheat
About the different types of wheat ... Check out the USDA Commodity Image Gallery
About the 8 major food allergens ... Start with the FDA's guidance for consumers and food manufacturers