There is a difference between food intolerance and food allergy.
Food allergy is a specific form of food intolerance that activates the immune system. An allergen provokes a chain reaction in the immune system and a release of antibodies. These antibodies cause the liberation of other molecules such as histamine, which sparks various symptoms such as a runny nose, coughing, sneezing or itching. Food allergies are often hereditary and usually identified early in life.
Food intolerance acts on the metabolism but not on the immune system. A good example is lactose intolerance. Some people are lacking in lactase, the enzyme that breaks down sugar and milk.
How common are food allergies?
- They affect 8% of children and 4% of adults in France*. They are on the increase and are now the fourth most frequent illness in the world (on the same level as respiratory illnesses).
- In children, 5 foods are responsible for around 79% of food allergies : egg, peanut, cow’s milk, mustard and fish.
- The French national health and nutrition programme (launched in 2001) aims to minimise food allergies by informing the public about the risks for young children.
What are the symptoms?
The allergy corresponds to an abnormal response from the immune system when in contact with the food (touch or ingestion). An allergic person’s organism perceives a normally harmless food as a danger and triggers its defence system. The organism reacts to the proteins (allergens) in the food by developing symptoms. They may be:
- Respiratory problems (rhinitis, asthma etc.)
- Eczema (redness, itchiness, swelling etc.)
- Urticaria (and sometimes oedema)
- Digestive problems (constipation, flatulence, diarrhoea etc.)
Anaphylaxis is a severe allergic reaction which can range from urticaria to pulmonary oedema. Medical assistance is necessary as anaphylaxis is life-threatening. Foods and symptoms vary according to age, but all appear a few minutes after and within two hours of ingestion.