Do you often suffer from abdominal cramps or other digestive problems? Or have recurrent coughing attacks, skin rashes or wheals? When the body reacts sensitively to food components, it can manifest itself in very different ways. That is why the diagnosis is often not so easy. But the reverse is also true: similar symptoms can be caused by different forms of food intolerance – which does not exactly simplify the search for the cause. To make matters worse, the terms are often not clearly defined or are used differently.
Food intolerance: what does it mean?
Food intolerances (LMU) are the generic term for all adverse, sometimes serious, reactions that occur within minutes to a few days after eating food. This includes both symptoms resulting from food poisoning in healthy individuals and symptoms triggered by food components only in particularly sensitive individuals, which is referred to as food hypersensitivity. This, in turn, is based on different mechanisms: either processes involving the immune system – as in food allergy (see below) and celiac disease – or those that occur without immunological reactions, the so-called food intolerances (see below). Unfortunately, the term food intolerance is often equated with food intolerance – which does not make it easier to understand.
Definitions
The following terms should be distinguished in the context of food intolerances:
- Food allergies (allergic food hypersensitivity): this hypersensitivity to a few or even many foods is one of the true allergies. Here, the immune system reacts with a defensive reaction to certain food components (especially eggs and other animal proteins, soy, nuts, seafood), which do not cause reactions in healthy people.
- Food intolerances (food intolerances): here, too, certain food components are not tolerated, but in contrast to the food allergy, no immunological mechanism is detectable. Here one distinguishes again two main groups:
- In the enzyme deficiency, the most common form of food intolerance, a protein is missing or functions only limited, which is needed for the digestion of certain food components: in the intestine for their breakdown or in the blood for metabolism. In most cases, the enzyme lactase is affected, which is needed to utilize the milk sugar (lactose) found in milk. If there is a lactase deficiency, the milk sugar is not broken down and thus no longer absorbed from the intestine (lactose intolerance, milk sugar intolerance). Less frequently, a fructose intolerance occurs.
- The pseudoallergies are not easily distinguished from the real allergies, because they have the same symptoms and often the same triggers as these. The difference is that messenger substances such as histamine, which cause the symptoms, are not released by the activated immune system, but directly by the food. Common triggers are biogenic amines (for example, in cheese, sauerkraut, spinach, tomatoes), salicylates (for example, in fruits and vegetables, honey), dyes and preservatives.
Symptoms of food intolerance
As described above, there are various causes that can trigger the same complaints – and these, in turn, not only play out in the gastrointestinal tract, but can also affect the respiratory tract, the skin or – in pronounced cases – the cardiovascular system. Typical symptoms are:
- Digestive tract: abdominal cramps, flatulence, nausea and vomiting, diarrhea (possibly bloody).
- Skin: itchy, red patches or wheals; tingling, burning and swelling on the oral mucosa.
- Respiratory: symptoms as in hay fever (stuffy noses, sneezing, watery eyes) or, due to swelling of the mucous membranes in the airways, shortness of breath as in an asthma attack. In the worst case, this can lead to life-threatening allergic shock with rapidly increasing shortness of breath.
Allergic and non-allergic intolerances.
The main difference between the allergic and non-allergic forms is that allergies are triggered by even the smallest amounts, while in intolerance reactions are often still tolerated. Thus, a “milk allergy sufferer” may not drink milk at all, while someone suffering from lactose intolerance may well consume small amounts without developing significant symptoms. Another distinguishing feature is that allergies (and pseudoallergies) occur at regular intervals in all those affected – depending on the type of food allergy (for example, itching and a feeling of tightness in the mouth after a few minutes, vomiting and diarrhea after one to two hours, and in some forms of allergy symptoms may occur only after one to two days), whereas in the case of enzyme deficiency the reactions vary greatly from person to person in terms of strength and timing. This is also related to the fact that the function of the affected enzyme is disturbed to varying degrees in each individual.
