In general, people sensitive to gluten are generally categorized as either 1) gluten sensitive or intolerant, 2) gluten allergic or Celiac Disease. A true allergy to gluten affects about one percent of people and involves a dangerous auto-immune response and progressive destruction to the intestine tract wall. An estimated three million American’s have been diagnosed with a gluten allergy and Celiac Disease, consistent with global findings of 0.5 - 1.0% of people. Meanwhile, gluten intolerance may impact up to 13 percent of people, according to some estimates, and while many of the symptoms are similar, destruction of the small intestine wall does not occur for these people.^1-3 

Many of the symptoms of either gluten intolerance or celiac disease include:

• Abdominal cramping, bloating, gas
• Diarrhea and/or constipation
• Vomiting
• Fatty (pale) stools
• Anemia
• Weight loss 
• Depression
• Headaches
• Fatigue, weakness
• Failure to grow properly (infants and children)
• Behavioral changes (infants and children)

For some people, gluten sensitivity can lead to very frustrating skin conditions, including dermatitis herpetiformis (DH). This condition, typically involving blistering and itching is more common on the hands, face, buttocks, and knees and involves. Small packets of immune factors (IgA) and an enzyme called transglutaminase can accumulate in the skin layers and used to make the diagnosis. Celiac disease is diagnosed as a physician brings together many of the hallmark and perhaps more obscure symptoms. Celiac disease can occur at any time but is most developed in childhood. 

Diagnosis of Celiac Disease typically involves a combination of blood antibody tests and intestinal biopsies. In addition, specific genetic marker testing can support other findings in the diagnosis. The impact of celiac disease can affect several areas and systems of the body often making the diagnosis challenging and separate from an intolerance. Often, some of the diagnostic testing is unclear and diagnosis may be a long process. However, the treatment involves restriction of gluten from the diet. 

Gluten is the dominant protein class in cereal grains and most of it is gliadin and glutenin. Gluten is responsible for the elastic and structural properties of flours used to bake flour-based products that rise. As gases are produced by yeast in dough, it gets trapped in the gluten-based network and the dough rises. People diagnosed with celiac disease need to avoid all foods containing gluten and thus must be recipe/ingredient readers.

Gluten is most notably found in wheat, rye, barley, and grains grown in regions with more extreme weather conditions (e.g., Canada and northern parts of the United States) tend to have more gluten. Gluten is not found in oats, rice, millets, buckwheat, sorghum, quinoa, and amaranth. However, it should be mentioned that many of the gluten-free grains can acquire some gluten if they are milled in the same facility as wheat, barley and rye or even grown next to these crops. 

Moreover, some people with celiac disease cannot tolerate certain types of oats or a significant serving of oats. This is because oats contain avenin which has some of the same amino acid characteristics as gluten. On the other hand, soy is not a grain and does not contain gluten and it is tolerated well by most gluten sensitive people.

In 2013, the US Food & Drug Administration issued a final rule defining “gluten-free” for food labeling, which is helping consumers, especially those living with celiac disease, be confident that items labeled “gluten-free” meet a defined standard for gluten content. “Gluten-free” is a voluntary claim that can be used by food manufacturers on food labels if they meet all the requirements of the regulations, namely the food bearing the claim does not contain an ingredient that is:

• A gluten-containing grain (e.g., spelt wheat)
• Derived from a gluten-containing grain and that has not been processed to remove gluten (e.g., wheat flour); 
• Derived from a gluten-containing grain and that has been processed to remove gluten (e.g., wheat starch), if that ingredient results in a final food with 20 parts per million (ppm) or more gluten

For context, 20 ppm is all about weight. So, 20 ppm is equal to 20 milligrams (mg) of gluten per kilogram (kg) of a food. Meanwhile, animal foods such as meats, eggs, dairy will not have gluten, nor will fruits and vegetables. The FDA discourages food companies are discouraged from marketed gluten free on foods that are naturally gluten free.