Yvonne Gifford experienced exhaustion for 20 years but couldn't figure out why. Mary Thorpe had a history of canker sores, migraine headaches and depression since her late teens, then developed digestive problems and itchy blisters on her legs a few years ago. Barbara Schneider suffered through frequent stomach distention for decades; three years ago, she developed chronic diarrhea and discovered she had very low bone density for a woman in her 60s.

For years, Gifford, Thorpe and Schneider experienced frustration with poor health. While these three women had very different systems, they eventually discovered a common cause: They are sensitive, possibly even intolerant, to gluten, a prevalent part of every American's diet. This gluey collection of proteins is found in wheat, rye, barley, oats, spelt, kamut, triticale and an endless variety of processed foods. Consequently, eliminating gluten from the diet isn't easy, but when these women did, their symptoms vanished and their health turned around.

A Spectrum Of Symptoms
Gluten sensitivity is an umbrella term that includes a wide variety of reactions to gluten. The worst manifestation is celiac disease, an autoimmune condition that destroys the lining of the small intestine, thereby interfering with nutrient absorption. Characteristic symptoms are bloating, diarrhea, acute abdominal pain, fatty stools and often weight loss.

Until recently, celiac disease was thought to be very rare, occurring in only one in every 4,850 Americans. However, recent research and newly developed blood-screening tests have led to shocking revelations. In fact, celiac disease is very common: One in every 167 healthy children and one in every 111 healthy adults suffer from the condition (Journal of Pediatric Gastroenterology and Nutrition, vol. 31, suppl. 3). Also, many people who have the disease, especially children, don't have the classic gastrointestinal symptoms that have commonly signaled the condition. In some cases, there are no symptoms at all. These people have "silent celiac disease"; the damage to the small intestine is as prevalent but without the obvious symptoms. As a result, many people go for years, sometimes decades, without a diagnosis while health complications worsen, says Alessio Fasano, MD, co-director of the Center for Celiac Research at the University of Maryland. The first indication of trouble may be anemia, osteoporosis or an autoimmune disease.

What's more, 10­25 percent of Americans are classified as gluten-sensitive, a more tolerant, less severe condition than celiac disease. These patients test positive for antibodies to gliadin, the key protein fragment celiacs cannot tolerate (Clinical and Diagnostic Laboratory Immunology, 2000, vol. 7), but they don't test positive to more definitive tests for celiac disease, such as the tissue transglutaminase (tTG) antibody blood-screening test and an intestinal biopsy.

Gluten sensitivity can cause a range of symptoms, including middle-ear disease, chronic inflammatory joint disease, asthma, some types of hyperactivity or depression, and some cases of a gluten-dependent skin condition called dermatitis herpetiformis, says James Braly, MD, author of Food Allergy Relief (Keats).

Determining if you have celiac disease and gluten sensitivity is important because an undiagnosed celiac who continues to eat gluten has a greatly increased risk for intestinal lymphoma and autoimmune diseases. In addition, people who have gluten sensitivity can develop celiac disease in the future.

According to Braly, high-risk candidates for celiac disease include people with:

• Insulin-dependent (Type I) diabetes;
• Autoimmune thyroid disease;
• Osteoporosis unresponsive to conventional treatment;
• Infertility and miscarriages;
• Chronic neurological conditions;
• Liver enzyme elevation;
• Down's syndrome;
• Sjögren's disease;
• Epilepsy and/or a history of migraine headaches;
• A genetic predisposition to intestinal lymphoma or esophageal cancer;
• Hyperactivity and/or digestive problems; and
• Close relatives who have celiac disease.

If you fall into the high-risk category, consider being tested for celiac disease, says Braly, especially if you're exhibiting health problems that cannot be traced to a cause.

Putting It To The Test
For testing, look for a gastroenterologist or nutritionally-oriented doctor who is familiar with the blood-antibody screens called anti-gliadin (IgG and IgA) and anti-endomysial antibody (anti-tTG). (If you have difficulty locating a practitioner in your area, see "Seeking Celiacs," below.) A positive reading on the initial test indicates a gluten sensitivity. A positive outcome on the second test denotes celiac disease, although your doctor may want to confirm the diagnosis by performing an intestinal biopsy. In either case, eliminate gluten completely from your diet, Braly says, and consider contacting a nutritionist or support group to help you do this.

Even if you aren't at risk for celiac disease or don't test positive on either of the tests, you may still benefit from a gluten-free diet. "People can have a sensitivity to gluten without having an immune reaction that shows up on a test," says Hunter Yost, M.D., a nutritional medicine practitioner in Tucson, Ariz. Yost puts his patients with chronic illness—everything from joint pain to immune system difficulties—on a diet free from both gluten and dairy and reports that the vast majority show dramatic results. Unexplained chronic illness may be corrected by going against the grain and giving up the gluten.

Melissa Diane Smith, Dipl. Nutr., is a Tucson, Ariz.-based nutritionist, health journalist and educator.