In food intolerance, the body does not form antibodies but reacts to a food with symptoms.
Food intolerance is a collective term for various non-allergic reactions to foods. Depending on the form of intolerance, up to 20% of the population are affected in Switzerland. Food intolerances cannot be detected by an allergy test. Milk sugar (lactose), fruit sugar (fructose), gluten and histamine are the most common triggers of intolerance, which is more common in adults than in children. Unlike food allergies, however, intolerances are not life-threatening.
In a food intolerance, the body has partly or totally lost the ability to digest a certain substance – or it has never had that ability. The body does not form antibodies but reacts immediately to a food with symptoms. Small quantities of the food that triggers the symptoms can usually continue to be eaten without any consequences.
The symptoms of a food intolerance can be many and varied. Most commonly these are general digestive complaints such as abdominal pains, flatulence, diarrhoea or constipation, queasiness. Other possible reactions: fatigue, irritability, skin rashes, headaches (migraine), circulatory problems, rheumatic complaints, etc. The symptoms often start insidiously. That is why it is not always easy to link these symptoms to a food intolerance.
It can be difficult to prove so-called intolerances. History-taking forms the basis of the diagnostic investigation . Depending on what is suspected, tests (e.g. genetic test in the blood for suspected lactose intolerance or H2 breath test for suspected lactose intolerance or fructose malabsorption) may be performed to confirm the suspicion. If no test is available, an elimination diet (diagnostic diet) is followed. Food intolerances include the following groups:
After diagnosis, those affected must eliminate the symptom-causing foods from their diet. In lactose, fructose and histamine intolerance the individual’s tolerance is ascertained in consultation with an HF/FH certified nutritionist. In coeliac disease, a strict gluten-free diet must be followed.
In terms of medication, the enzyme lactase can be taken as a tablet for lactose intolerance and the enzyme diamine oxidase for histamine intolerance.
Editors: aha! Swiss Allergy Centre in co-operation with the Scientific Advisory Board. For prevalence figures, see source references.