Prevalence and symptoms

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.

 *Source: PNNS

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.