Nutrition Science and Everyday Application - beta v 0.1

FOOD INTOLERANCES, ALLERGIES, AND CELIAC DISEASE 165
but the presence of IgG does not indicate a food allergy. Therefore, these tests are not
recommended by allergy experts, because they may cause a person to unnecessarily fear
and avoid a long list of foods to which they are not allergic. 8
CELIAC DISEASE
Celiac disease is an autoimmune disorder affecting between 0.5 and 1.0% of people in
the U.S., or one in every 100 to 200 people. 9 Inautoimmune diseases, the immune system
produces antibodies that attack and damage the body’s own tissues. In the case of celiac
disease, the body has an abnormal immune reaction to gluten (a group of proteins found in
wheat, rye, and and barley), causing antibodies to attack the cells lining the small intestine.
This results in damage to the villi, decreasing the surface area for nutrient absorption. There
is no cure for celiac disease, but it’s very effectively treated by eliminating gluten from the
diet. 10
Symptoms of celiac disease can range from mild to severe and can include pale, fatty,
loose stools, gastrointestinal upset, constipation, abdominal pain, and skin conditions.
Nutrient malabsorption can lead to weight loss and in children, a failure to grow and thrive.
Symptoms can appear in infancy or much later in life, as late as age seventy. Celiac disease
is not always diagnosed, because the symptoms may be mild. Even without symptoms,
the disease can still damage the small intestine and impair nutrient absorption. Nutrient
deficiencies can cause health problems over time, particularly in children and the elderly.
For example, poor absorption of iron and folic acid can cause anemia, which impairs oxygen
transport to cells in the body. Calcium and vitamin D deficiencies can lead to osteoporosis, a
disease in which bones become brittle.
Diagnosis of celiac disease begins with a blood test for specific antibodies that are elevated
in those with the disease. If the blood test is positive, the diagnosis is confirmed with a
biopsy of the small intestine, a procedure in which a small amount of tissue is removed
for examination. These tests may not accurately detect celiac disease in people already
consuming a gluten-free diet, because without gluten, antibody levels may be low and
damage to the small intestine may not be visible. This is why it’s best to be tested for celiac
before eliminating gluten from the diet.
It isn’t clear what causes celiac disease; genetics play a role, but other factors also seem
to influence its development. Celiac disease is most common in people of European descent
and is rare in people of African American, Japanese, and Chinese descent. It is more
prevalent in women and in people with type 1 diabetes, autoimmune thyroid disease, and
Down and Turner syndromes.
Celiac disease is treated by completely avoiding gluten, as consuming even small amounts
can cause intestinal damage. People with celiac can consume grains that don’t contain
gluten, including rice, corn, millet, buckwheat, and quinoa. Oats can be consumed, although
they are often contaminated with gluten from neighboring fields or shared processing
equipment, so it’s best to buy oats labeled gluten-free. There are also an increasing number
of gluten-free products available in stores. After eliminating gluten from the diet, the tissues
of the small intestine usually heal within six months.