Alactasia Health Dictionary

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Alactasia: From 1 Different Sources

n. absence or deficiency of the enzyme lactase, which is essential for the digestion of milk sugar (lactose). All babies have lactase in their intestines, but the enzyme disappears during childhood in about 10% of northern Europeans, 40% of Greeks and Italians, and 80% of Africans and Asians. Alactasia causes symptoms only if the diet regularly includes raw milk, when the undigested lactose causes diarrhoea and abdominal pain.
Health Source: Oxford | Concise Colour Medical Dictionary
Author: Jonathan Law, Elizabeth Martin

Food Intolerance

This is divided into food aversion, where a person simply avoids a food they dislike; food intolerance, where taking the food causes symptoms; and food allergy, where the symptoms are due to an immunological reaction. Some cases of food intolerance are due to idiosyncrasy – that is, a genetic defect in the patient, such as alactasia, where the intestine lacks the enzyme that digests milk sugar, with the result that individuals so affected develop diarrhoea when they drink milk. Intolerance to speci?c foods, as distinct from allergy, is probably quite common and may be an important factor in the aetiology of the IRRITABLE BOWEL SYNDROME (IBS).

For the diagnosis of true food allergy, it is necessary to demonstrate that there is a reproducible intolerance to a speci?c food; also, that there is evidence of an abnormal immunological reaction to it. Occasionally the allergic response may not be to the food itself but to food contaminants such as penicillin, or to food additives such as tartrazine. There may also be reactions to foods which have pharmacological effects, such as ca?eine in strong co?ee or histamine in fermented cheese, or such reactions may be due to the irritant e?ect on the intestinal mucosa (especially if it is already diseased) by, say, highly spiced curries.

Testing blood and skin for food allergy is beloved of some alternative practitioners but, in practice, the results of tests do not necessarily agree with what happens when the food is taken. Therefore, a careful history is as useful as any test in making a diagnosis.... food intolerance


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