Food allergies

Food allergy: When food becomes the enemy

Food allergy is a specific immune system reaction to proteins found in certain foods. It is important not to confuse true allergy with food intolerance. Intolerance (for example, lactose intolerance) is a digestive problem related to enzyme deficiency and it does not involve the immune system. Allergy, however, is an immune attack that can have serious, sometimes life‑threatening consequences.

Immune mechanism: Why the body attacks food proteins

Food allergy is based on an IgE‑mediated reaction. The immune system of an allergy‑prone person mistakenly perceives an absolutely safe food protein as a threat. In response to the first contact with this protein, the body produces specific IgE antibodies. Upon subsequent consumption of the product these antibodies activate mast cells, leading to the release of histamine and other inflammatory mediators. This causes a rapid allergic reaction, usually within a few minutes to two hours.

Although any food can trigger an allergy, over 90% of all reactions are linked to the so‑called "big eight" allergens:

• Milk
• Eggs
• Peanut
• Tree nuts (almond, walnut, cashew)
• Soy
• Wheat
• Fish
• Shellfish

Manifestations of food allergy: From itching to anaphylaxis

Symptoms can range from mild to severe. The skin is most often affected (as hives or swelling), the digestive system (nausea, vomiting, abdominal pain) and the respiratory system (wheezing, cough). The most dangerous manifestation is anaphylaxis—a systemic reaction that threatens life. There is also oral allergy syndrome, where itching and swelling in the mouth occur in response to raw fruits and vegetables in people with pollen allergy due to cross‑reactivity.