Читать книгу The Food Intolerance Bible: A nutritionist's plan to beat food cravings, fatigue, mood swings, bloating, headaches and IBS - Antoinette Savill, Antoinette Savill - Страница 6

Before going any further I am going to clarify the distinction between a food allergy and a food intolerance. This has been a source of confusion, not least for those in the health profession.

Originally, the word allergy was designated to mean any adverse reaction to any substance inhaled or eaten or coming into contact with the skin, with no specific limitations on the specific nature of the immune reactivity. However, over time, the term food allergy has been taken on by allergists and relates to immune reactions mediated by the immunoglobulin E (IgE), which could be to a food or something inhaled or to which we might come into direct physical contact.

Immunoglobulin is a protein that carries out various roles in the body’s immune response. There are five: immunoglobulin G, A, M, D and E. Immunoglobulin G (IgG) plays the most significant role of the five in terms of food intolerance, whereas immunoglobulin E (IgE) triggers the most significant reactions. However, not all food intolerance reactions are related to our immune system. For example, tyramine – found in strawberries, cured meats and cheese – can trigger migraines in some people, and this is a brain reaction, not an immune-based one.

Reactions mediated by IgE are referred to as ‘true food allergies’ – somewhat of a misnomer since it implies that any other type, such as a food intolerance, is ‘untrue’. Having said this, these true food allergy reactions are almost always immediate in their manifestation and therefore most often can be traced back to a particular cause. They can often affect health in a significant and rapid manner – swollen lips and tongue, asthma attack – reactions can be life-threatening, which is why great care needs to be taken to avoid the trigger foods or substances. Peanut allergy and shellfish allergy, for example, are perhaps the most well known. Another example is an allergy to latex (rubber) – of allergies triggered just by coming into contact with a substance, this is the one on the most rapid increase. So much of a problem is this specific allergy that at least one hospital has had to change the material of its surgical gloves lest a nurse or doctor succumb to anaphylaxis.

Anaphylaxis is an extreme physical reaction – the reason for which is not fully understood – that often requires adrenaline to counter the extreme stress-reaction caused in the body.