Food hypersensitivity is an umbrella term which can be used to describe adverse reactions to food. There are two different types of food hypersensitivity – food allergy and food intolerance.
Generally speaking, food allergy involves the body’s immune system. Symptoms can develop rapidly (usually within minutes) and can be serious and sometimes life threatening (known as anaphylaxis). However, some allergic reactions (such as diarrhoea, vomiting and constipation) do develop more slowly. Peanut allergy is an example of a food allergy.
Symptoms of food allergy can include: diarrhoea, vomiting, coughing, itchy skin or rash, wheezing and shortness of breath, swelling of lips and throat and faintness.
Food intolerance is where the body’s reaction to food does not involve the immune system. Symptoms can be severe and unpleasant but are not usually as serious as the symptoms of food allergy and tend to develop more slowly (i.e. hours or days after the food has been eaten). Larger amounts of foods are needed to cause a reaction and the amounts can vary from person to person. Food intolerance is sometimes also called non-allergic food hypersensitivity. Wheat intolerance or lactose intolerance are examples of food intolerances.
Symptoms of food intolerance can include: flushing, headaches, wheezing, runny nose, altered bowel habits, bloating, abdominal pain etc. People can be allergic or intolerant to more than one food.
How common are food allergies and intolerances?
Food allergy is believed to affect approximately 3% of adults and 6-8% of children. Around 20% of the adult population feel that they have a food intolerance. Wheat allergies and intolerances seem to be a common hypersensitivity in adults and children but the exact number of sufferers is unknown.