Gluten

Gluten (from Latin gluten "glue") is a protein composite that appears in foods processed from wheat and related species, including barley and rye. It gives elasticity to dough, helping it to rise and to keep its shape, and often giving the final product a chewy texture.

As the cases of alleged gluten sensitivity increases, many foods are now labeled to clarify whether they contain gluten.

Gluten is the composite of a prolamin and a glutelin, which exist, conjoined with starch, in the endosperm of various grass-related grains. Gliadin and glutenin (the prolamin and glutelin from wheat) comprise about 80% of the protein contained in wheat seed. Being insoluble in water, they can be purified by washing away the associated starch. Worldwide, gluten is a source of protein, both in foods prepared directly from sources containing it, and as an additive to foods otherwise low in protein.

The seeds of most flowering plants have endosperms with stored protein to nourish embryonic plants during germination. True gluten, with gliadin and glutenin, is limited to certain members of the grass family. The stored proteins of maize and rice are sometimes called glutens, but their proteins differ from wheat gluten by lacking gliadin.

Gluten Intolerance: Against the Grain

Many people blame wheat, found in most of the grain-based products, for causing their abdominal pain, gas, bloating and diarrhea.

"But more likely, gluten is what's irritating your gut," says Leslie Bonci, MPH, RD, author of the American Dietetic Association Guide to Better Digestion.

Gluten, the protein found in wheat, rye, and barley, is the common denominator in most of the grain-based products we eat, such as cereals, breads, and pasta.

Simple gluten intolerance can be uncomfortable, but the symptoms are fleeting, Bonci says. The good news is that gluten intolerance is not a food allergy, and eating gluten does not usually cause damage - unless you have celiac disease.

Celiac Disease: When Symptoms Are More Serious

More serious gluten intolerance is called celiac disease. That's when gluten actually triggers the body's immune system. When people with celiac disease eat foods or use products containing gluten, their immune system responds by damaging the villi -- tiny, fingerlike projections in the small intestine that absorb the nutrients from food. For this reason it's considered an autoimmune disease.

Celiac disease, which also goes by the names gluten-sensitive enteropathy, nontropical sprue, and celiac sprue, is a genetic disease. This means it can run in families. And it has far-reaching effects.

"Celiac disease is not just a disease of the gut," says Shelley Case, R.D., nutrition consultant and author of Gluten Free Diet: A Comprehensive Resource Guide. "It's a multi-system, multi-symptom disease with serious implications."

Celiac disease is linked to malnutrition that can lead to anemia, osteoporosis, depression, behavioral problems, and stunted growth in children, among other problems. People who have celiac disease may also have other autoimmune conditions, such as type 1 diabetes and rheumatoid arthritis.

Celiac Disease: When Symptoms Are More Serious

More serious gluten intolerance is called celiac disease. That's when gluten actually triggers the body's immune system. When people with celiac disease eat foods or use products containing gluten, their immune system responds by damaging the villi -- tiny, fingerlike projections in the small intestine that absorb the nutrients from food. For this reason it's considered an autoimmune disease.

Celiac disease, which also goes by the names gluten-sensitive enteropathy, nontropical sprue, and celiac sprue, is a genetic disease. This means it can run in families. And it has far-reaching effects.

"Celiac disease is not just a disease of the gut," says Shelley Case, R.D., nutrition consultant and author of Gluten Free Diet: A Comprehensive Resource Guide. "It's a multi-system, multi-symptom disease with serious implications."

Celiac disease is linked to malnutrition that can lead to anemia, osteoporosis, depression, behavioral problems, and stunted growth in children, among other problems. People who have celiac disease may also have other autoimmune conditions, such as type 1 diabetes and rheumatoid arthritis.

Celiac Disease: An Unrecognized Problem

Until fairly recently, celiac disease was considered rare among Americans. In 2003, the results of a large, multi-center study published in the Archives of Internal Medicine found celiac disease in one in 133 Americans. Among those with parents, siblings, or children with celiac disease, up to one in 22 people in the study had it.

As many as three million Americans have celiac disease. Most of them don't know it, largely because celiac disease can be difficult to nail down.

"It takes most adults about 12 years to get a definitive diagnosis of celiac disease," says Michelle Pietzak, MD, a pediatric gastroenterologist, professor of pediatrics at the Keck School of Medicine of the University of Southern California, and one of the authors of the landmark study.

Gluten Intolerance: Searching For Answers

If you think you suffer from celiac disease, resist putting yourself on a gluten-free diet. At least not yet.

"When you go off gluten, your gut starts to heal, and you won't have the markers in your blood or your gut tissue that indicate celiac disease," Case says.

Instead, see a doctor for testing and a firm diagnosis. Your doctor usually orders blood tests to help diagnose celiac disease. The two most frequently ordered tests are the endomysial antibody and tissue transglutaminase antibody tests.

If antibody tests suggest celiac disease, you'll need to confirm the diagnosis with a biopsy of your small intestine. The appearance of dermatitis herpetiformis (DH), an itchy, blistering skin rash is also a strong indicator of celiac disease.

Adapting to a Gluten-Free Diet

You absolutely must avoid gluten if you have celiac disease. That's the only way to halt the disease's symptoms, heal existing villi damage, and prevent destruction of the small intestine. Even if you have only a mild reaction to gluten, you may decide to keep this protein out of your diet.

But gluten-free living is no mean feat. That's why it's important not to go it alone. You may think you're doing a good job of getting rid of gluten, but you may not be aware that gluten lurks in a number of processed foods, including:

• Salad dressings
• Cold cuts
• Egg substitutes
• Beer
• Instant flavored rice mixes
• Flavored potato chips
• Imitation crab (surimi)
• Some herbal teas
• Licorice and some chocolates

The advent of gluten-free specialty stores and Internet sites is a boon to those who must avoid gluten. Case notes that more restaurants are catering to gluten-free dining. The Gluten-Free Restaurant Awareness Program (www.glutenfreerestaurants.org/), run by the Gluten Intolerance Group of North America, is one  source of gluten-free fare available throughout the US. 

But, Case cautions diners to resist resting on their laurels when eating in establishments that participate in the program, or who otherwise tout themselves as gluten-free. “Continue to ask a lot of questions about how your food is prepared,” she says.

Designing a Gluten-Free Diet

Pietzak says it's important to seek help from a registered dietitian when you decide on a gluten-free diet. Registered dietitians are trained to design personalized gluten-free diets that work with your nutrient needs and lifestyle. For the best results, choose a dietitian expert in gastrointestinal disorders.

Dietary counseling is even more important for children with celiac disease and their parents because growing bodies have special nutrient needs. "If you have a child with celiac disease, you may want to consider a gluten-free household to make life easier," Pietzak says.

A gluten-free eating plan seems restrictive because it eliminates many types of grain products such as breakfast cereals, breads, and pasta. But it's not as harsh as it sounds.

"I tell people that the foods you should be eating a lot of anyway, such as fresh meats, fruits, vegetables, milk, and legumes are naturally gluten-free," Case says. The key is knowing which grains to eat and which to avoid.

Don't eat:

• Wheat and all its forms, including semolina, spelt, kamut, einkorn, and farro
• Rye
• Barley
• Triticale
• Oat bran
• Wheat germ
• Bran
• Graham, gluten, or durum flour
• Farina

Do eat:

• Amaranth
• Quinoa
• Buckwheat
• Popcorn
• Cornmeal (polenta and tortillas)
• Millet
• Breads, cereals, crackers, and pasta made of corn, rice, potato, soy, arrowroot, tapioca, sago, flax, and hominy.

What about oats? Oats for celiac disease has been controversial, but recent research has spurred many organizations to give oats the thumbs up. The problem is possible contamination of oats with other gluten-containing grains. Case says pure oats - those not contaminated by other grains - are recommended by a majority of celiac organizations in Canada and the U.S.