excerpt of an article from Whole Foods Market
Celiac disease defined
Celiac disease, also known as coeliac disease, gluten-sensitive enteropathy, non-tropical sprue, celiac sprue, and gluten intolerant enteropathy, is a chronic digestive disorder found in individuals who experience a toxic immune response when they ingest gluten. Dermatitis herpetiformis is a related skin condition experienced by some celiacs. There is no cure for celiac disease. The only known treatment is lifelong adherence to a gluten-free diet. Ingesting gluten affects the function of the small intestine of celiacs by damaging and/or destroying the absorptive villi. The body then becomes unable to properly absorb nutrients, resulting in potentially life-threatening nutritional deficiencies and even intestinal lymphoma.
Cause of celiac disease
Celiac disease is thought to have a strong genetic component. The onset of celiac disease has been associated with genes on Chromosome 6 called Human Leukocyte Antigens (HLA) class II. HLA II genes affect an individual's susceptibility to disease by mediating the interactions between cells of the immune system. An individual may be genetically predisposed to celiac disease, but the actual mechanism of onset is not fully understood. Emotional stress, physical trauma, viral infection, pregnancy, and surgery are some of the factors implicated in the onset of celiac disease.
Prevalence of celiac disease
Celiac disease is the most common genetic disease in Europe. In Italy about 1 in 250 people and in Ireland about 1 in 300 people have celiac disease1. A University of Maryland study of over 13,000 subjects demonstrated the prevalence at 1 in every 133 Americans have celiac disease. This study was released in February 2003.
Celiac disease is most common in Caucasians, but has been diagnosed in Asians from India and Pakistan. It is rarely diagnosed in Japanese, Chinese or Africans. Because of the genetic component of the disease, it is found in 5 to 15 percent of siblings and offspring of celiacs. There is a 70 percent concordance among identical twins.
Symptoms of celiac disease
The term "celiac" or coeliac is of Greek origin and means "of or in the cavity of the abdomen." The condition known as celiac disease was so named because many of the cardinal symptoms and effects of the disorder are related to the gastrointestinal tract.
However, the full range of symptoms of celiac disease are varied and may occur at any time in the life of an individual who is genetically predisposed to the disorder. A significant number of people show no clinical symptoms, but are still incurring intestinal damage. Some symptoms include:
- intestinal bloating or "pot belly"
- intestinal gas
- steatorrhea (fatty, floating and voluminous stools)
- lack of energy
- bone or joint pain
- depression or irritability
- dental enamel defects
- folate deficiency
- osteopenia and osteoporosis (bone mineral loss)
- infertility problems in women
- failure to thrive in children
- weight loss or wasting
Dermatitis Herpetiformis (DH) is a related skin condition characterized by blistering, itchy rashes on the back, legs, buttocks, and arms. Between 60 and 80 percent of those who suffer from DH also incur damage to the intestinal villi.
Medical conditions associated with celiac disease
(Note: the nature of the association between these conditions and celiac disease is unknown. Celiac disease does not necessarily cause these disorders or vice versa. Factors that predispose a person to contracting celiac disease may also make them vulnerable to these other immunological disorders.)
- neurological complications
- kidney and liver disease
- insulin dependent diabetes mellitus
- systemic lupus erythematosus
- selective IgA deficiency
- thyroid disease
- lactose intolerance
- chronic active hepatitis
- myasthenia gravis
- Addison's disease
- rheumatoid arthritis
- Sjogren's syndrome
Diagnosing celiac disease
Definitive diagnosis of celiac disease is complicated by the similarity of many of the symptoms to other conditions. Individuals may be screened for celiac disease using antigliadin, antireticulin, and antiendomysium antibody tests. Raised blood serum levels of these antibodies in patients with active celiac disease have been shown to correlate well with the degree of damage occurring in the small intestine. However, intestinal biopsy is still considered the most reliable diagnostic tool. A biopsy before and after the adoption of a strict gluten-free diet allows the physician to observe the pre- and post-exposure status of the intestinal villi. The complete diagnosis may take quite a long time because healing of the villi may take months or years on a gluten-free diet. DH is diagnosed by performing a biopsy of the affected skin and staining for the presence of IgA.
Despite the difficulty in diagnosing celiac disease, early recognition of the disorder may reduce the risk of the development of malignant intestinal lymphomas, as well as serious bone mineral loss. Even celiac disease sufferers who experience no observable symptoms are at risk for suffering these problems.
History of celiac disease research
The symptoms of celiac disease, including the wasting and characteristic stools, were described as early as the first century A.D. Celiac disease and it's dietary component was detailed in the medical literature in 1888. In 1950, a Dutch pediatrician named Dicke proposed wheat gluten to be the cause of the disease. He based this theory on his observations that celiac children improved during World War II when wheat was scarce in Holland. Subsequent research isolated gliadin and the other peptides mentioned above as the portion of the gluten that triggered the intestinal damage. In 1989, research indicated a significant reduction in malignancies when celiac disease was treated with a gluten-free diet. Researchers continue to investigate celiac disease, honing in on the exact causes and implications for treatment.
What is gluten?
In terms of the medical definition of Celiac Disease, or Gluten Intolerance, "gluten" is defined as the mixture of many protein fragments (called peptide chains or polypeptides) found in common cereal grains — wheat, rye, barley and sometimes oats (oats don’t naturally contain gluten, but are often subject to contamination with small amounts). Wheat is the only grain considered to contain true "gluten" and the peptides that predominate in wheat gluten are gliadin and glutenin.
Gliadin is thought to be the peptide chain that instigates the toxic immune response and subsequent intestinal damage in celiacs. However, other protein fragments thought to be toxic to celiacs occur in rye, barley, and oats. They are secalins, hordeins, and avenins, respectively. Even though some research suggests that the avenins are not toxic, most celiacs still avoid oats just to be safe. Minute amounts of any of these protein fragments can cause intestinal damage in people with celiac disease. Because the disease is not fully understood, it is thought there may be other peptide chains including some derived from glutenin, that are also toxic. Because of the lack of definitive research on the disease, celiacs must often live by the saying, "when in doubt, leave it out."
Safe grains for celiacs
Current scientific consensus is that rice and corn (maize) are considered safe for celiacs. In addition, millet, sorghum, Job's Tears, teff, and ragi are thought to be close enough to corn in their genetic make-up to be safe. More research is needed to substantiate this. Other grains suspected, but not proven, to be safe for celiacs include buckwheat, amaranth, quinoa and rape. Although their safety is debated, they are only very distantly related to wheat. Thus, it is unlikely their peptide chains are the same as the problematic chains found in wheat, rye and barley.
Sources of gluten
- wheat (including semolina, durum, spelt, triticale, and Kamut® grain)
- oats (oats don't naturally contain gluten, but are often subject to contamination with small amounts and many gluten intolerant people avoid oats)