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Prepared by Sandra Tamm





In terms of "late food allergy" and "hidden food allergy", the word "allergy" causes confusion, so the term "food intolerance" (1) is often used. However, this is misleading, as an allergy is an immunological reaction, while a food intolerance is not (2).


Allergythe symptoms appear immediately after consuming the food and are related to the production of only one type of antibody - E-immunoglobulins, or IgE antibodies. We talk about food intolerance when our body cannot tolerate a specific food and the reactions are not immune-mediated (3).


As a result of daily eating of an intolerable food, specific compounds accumulate in the body, which can cause serious health disorders.


Some of the more common known health problems that intolerance can cause (1).

  • Headache or migraine

  • Diarrhea, sometimes with flatulence and bloating (often diagnosed as irritable bowel syndrome)

  • Abdominal pains

  • Constipation

  • Nausea, indigestion

  • Joint pain

  • Muscle pain

  • Constantly running or stuffy nose

  • Ear problems

  • Fatigue and vague general malaise

  • Depression

  • Ear infections


The above-mentioned health problems can also manifest themselves in the case of allergies.



Different forms of intolerance(2)



Pharmacological - food intolerance can often be caused by chemical compounds affecting the state of our tissues, such as histamine, tyramine, etc., which are released from connective tissue cells without an allergic reaction. This can be caused by foods that so-called release histamine: egg white, carp, strawberries, tomato, chocolate, citrus fruits, pork or additives. Also, fermented foods such as cheese, sauerkraut, alcoholic beverages contain a lot of histamine and tyramine and can cause food intolerance.


Enzymatic - in this form of food intolerance, a person has little or no enzyme. Some examples:


  • Lactase deficiency -  is one of the most common and causes lactose intolerance. May or may not be hereditary.

  • Trehalase deficiency - in this case, the person lacks the enzyme trehalase, which breaks down the sugar found in large mushrooms and most other fungi (including yeast).

  • Galactosemia – a problem with the enzyme that processes galactose. It is a very serious disease and people with this condition must completely avoid milk (including breast milk).


With an unknown mechanism of formation- reactions are usually caused by chemical compounds, most often food additives, or so-calledE substances.


Due to metabolic disorders- näiteks fenüülketonuuria ((FKU) on aminohapete ainevahetuse häire, mille korral on ensüüm fenüülalaniini hüdroksülaasipuudulikkuse tõttu häirunud aminohappe fenüülalaniin (Phe) hüdroksüleerimine organismis Phe is a component of dietary protein, which is also found in breast milk and normal infant formula. In FKU, the Phe obtained from food remains unhydroxylated, accumulates in the blood and is then deposited in the brain tissue, which causes the child's development to be delayed. If the disease is diagnosed early, a therapeutic diet can be started and the child's development proceeds normally. FKU is the most common hereditary metabolic disease in Estonia, with an incidence of 1:6080.


The screening test measures the level of the amino acid phenylalanine (Phe) in whole blood) (4) and fructose intolerance (Dr. Kristel Ehala-Aleksejev, doctor of internal medicine at the University of Tartu Clinic: "Hereditary fructose) to detect FKU intolerance is a rare disease in which the metabolism of fructose in the liver is disturbed. The latter should not be confused with a disorder of fructose absorption from the intestine, which is more common and associated with symptoms of the intestinal tract, such as increased gas production, diarrhea, in more severe cases, nausea-vomiting (depending on the patient and the presence of the disorder) of intensity).The best way is to avoid products that contain fructose." )



Diagnosis of intolerance


  • Intolerance caused by metabolic disorders and enzyme deficiency (deficiency) is diagnosed in medicine with appropriate diagnostic tests.

  • Elimination diet - for a certain periodeliminating and then reintroducing foods, at the same time the reactions occurring in the body are monitored by keeping a food diary.






Used sources:

1. Gamlin, Linda, “Handbook of Allergy”, 2009

2. Julge, Kaja, dr. Vasar, Marje, dr. "Food and Allergy", 2004



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