What is Celiac Disease?
Celiac disease is a disorder that causes the body's immune system to respond to the protein in certain grains (Bower, 2007, p.2). It is a multisystem disease which is one of the most underdiagnosed hereditary autoimmune disorders (Green, 2010, p. 20). In this autoimmune disorder, the body negatively reacts to certain protein chains called glutens. The body attacks itself when gluten enters the intestines. The negative reaction causes the villi of the small intestine to become damaged and eventually destroyed. This damage extends to other parts of the body as it progresses (Green, 2010, p. 20). The intestinal villi are very important nutrient absorbers, and they help the body get the benefit from the food that is eaten. When the villi in the small intestine are damaged, nutrients cannot be absorbed, and malnutrition results. It is still unclear why this response occurs only in certain genetically predisposed individuals and can be triggered at varying times in their lives (Green, 2010, p.20). The diagnosis for celiac disease is life-long. The patient never "outgrows" it (Green, 2010, p. 4).
Celiac disease is passed on genetically. There is a 10% chance that first degree relatives of a patient have celiac disease (James, 2010, p. 107). At this point, there are two genes associated with the disease. They are HLA-DQ2 and HLA-DQ8. The patient must have at least one of these genes to have celiac disease (James, 2010, p. 107). However, people with these genes do not necessarily have the disease; they might be carriers only.
What is Gluten?
Gluten is the environmental trigger that has to be ingested to manifest celiac disease. It is found in many foods in our modern society and the patient with the disease needs to be proactive to avoid it. Gluten is commonly found in baked goods and pastries made with wheat flour. Gluten holds the dough together and makes the dough pliable, thick and able to be kneaded (Bower, 2007, p. 65). Its name comes from the Latin gluten, for glue (James, 2010, p. 106). Without gluten, bread dough is not very elastic. Processed foods often use gluten products as filler and thickening agents.
The best description of gluten and its related "issue-makers" can be found in Celiac Disease: A Hidden Epidemic, by Green and Jones:
Gluten - The storage protein of wheat. Essentially, the portion of wheat flour that makes it sticky. The gluten fraction that is most studied in celiac disease is called gliadin, but there are other proteins that chemically resemble gliadin in rye (secalins) and barley (hordeins). These proteins are not strictly glutens, but are generally included in the term and are toxic to people with celiac disease.
Why is Gluten an Issue?
Gluten is a combination of two other proteins called gliadin and glutenin. They are known as prolamins because they are rich in the amino acid, prolamine (Bronski, 2012, p. 20). It is the gliadin protein that causes the body to go on the attack for the patient with celiac disease when gluten is ingested (James, 2010, p. 106). "The chemical make-up of the gliadin, hordein, and secalin cause the body to have an immune reaction" (Bower, 2007, p. 2).
Let's put this process under a microscope. Gluten is composed of proteins and proteins are made up of chains of amino acids. First, the amino acids are strung together, like pearls on a necklace (primary structure). Then the amino acid necklace twists and turns on itself (tertiary, or three dimensional at this point). Sometimes those three dimensional structures bind together (quaternary structure). All of the structures except the primary structure have weak amino acid bonds (Bronski, 2012, p. 20). When those weak bonds are broken, the protein is said to be denatured.
Bronski, in The Gluten-Free Edge, points out that we denature proteins all the time. When egg whites are beaten until they are stiff, that is a reversible denaturing. If an egg is cooked, and the color turns from clear to white, that is an irreversible denaturing.
At the most basic level of structure, the primary structure talked about above, it is the job of the enzymes in the body to break the amino bonds of the chains (Bronski, 2012, p. 20). These enzymes break down the peptides (multiple amino acids strung together) into individual amino acids so that the body can absorb them and use them. They do this in several different ways. Some of the enzymes eat along the string starting from the ends. Other enzymes act as scissors and move along the chains snipping the bonds (Bronski, 2012, p. 20).
Even in people not diagnosed with celiac disease, gluten resists the bond breaking enzymes (for the most part) and travels through the digestive system virtually undigested.
Where is Gluten Found?
Gluten is found in wheat, rye, barley, triticale, kamut, spelt and all of their derivatives. This means that under the heading of wheat, you would find farina, graham, semolina, durum, bulgur, and matzo, all dangerous for those with celiac disease. Under the heading of barley, anything with malt (chocolate malt) or malt flavoring (beer) would not be safe to consume. Also on the unsafe food list are oats. They do not contain gluten, but are often exposed to cross contamination during the manufacturing process due to the fact that they are usually grown next to and processed with wheat.
The person with celiac disease must learn to read labels scrupulously. Wheat is often used as filler for many food and non-food products. When formulations change, the labels must be checked again for the presence of gluten. Medications can contain gluten and the patient must check directly with the manufacturer to ensure their own safety.
A product might not contain gluten in the ingredients, but if it is manufactured in a facility with other gluten-containing products, it is considered unsafe for the person with celiac disease because cross contamination can occur. Many manufacturers are now labeling their products with allergy information, including the presence or exposure to wheat.