Gluten, a protein in certain grains (wheat, rye, barley, sometimes oats, also in lots of prepared foods), triggers our immune system to mistakenly attack the body itself (one of a category of auto-immune diseases). Celiac Disease only occurs in people with certain genetic dispositions (which can’t be accurately predicted ahead-of-time). It’s most common among persons of northern European ancestry, but also occurs in other ethnic groups. Celiac disease is quite common, maybe 1 in 100 people have it, more within families.
The classic symptom is chronic diarrhea, often with lots of gas, bloating, & smelly stools. A person can be fatigued, and lose weight. Diagnosis is made by a blood test — the best one is Tissue Trans-Glutaminase (tTG), IgA antibody. It has to be the IgA, other tTG antibodies aren’t as accurate. The patient has to be eating wheat products, etc.; a gluten-free diet for 2 weeks will interfere with testing. Another test might be the anti-Gliaden antibody; others aren’t as accurate.
Patients with positive tests are then usually referred to gastroenterologists, who perform endoscopy to obtain a biopsy of the small intestine. However, if the patient begins a gluten-free diet between the blood test & endoscopy the biopsy may be false-negative (biopsies and blood tests should be done while still eating gluten for at least 2 weeks). Also, abnormalities of the small intestine may be patchy, so the biopsy may miss them (false-negative). As such, the tTG may be best of all.
We’re realizing bit by bit that many patients with Celiac Disease don’t have much diarrhea. The illness can cause all sorts of other symptoms & problems that have nothing to do with the bowel, These may include:
- itchy rash (groups of bumps or blisters on arms, knees, back, scalp, or buttocks)
- poor growth in children
- weak tooth enamel
- numbness & tingling in hands or feet (neuropathy)
- abnormal liver tests
- depression, anxiety, even psychosis
- miscarriages, infertility, early menopause
Treatment is eliminating gluten from the diet. This may be difficult in our society, and requires careful reading of all processed foods. Depending on the severity of the disease, even tiny amounts may be bad (like food prepared on cutting boards just used to slice bread, etc.). A nutritionist can be an enormous help. Keeping a strict diet is important, not just to control symptoms, but because celiac disease is associated with a number of cancers (especially lymphoma).
It’s becoming faddish among some people to have to eat gluten-free. But for either biopsy or blood tests to be accurate, they shouldn’t be done during a gluten-free diet. However, once someone has eliminated gluten, they may not want to eat it again (takes 2 weeks of gluten to get accurate tests). Unfortunately, as with lots of treatments, there are strong placebo effects (even though nobody wants to admit it for themselves). So if you really & honestly want to know if you need to avoid gluten, get the tests before trying your own diet.