The terms “food allergy” and “food intolerance” are sometimes used interchangeably, but are in fact quite different. While a person might declare that he or she is allergic to a particular food, in some cases they are actually referring to food intolerance rather than an allergy – a condition which, while unpleasant, may not be quite as serious.
A true allergy in the traditional sense is an acute immune response (IgE antibody) to a food or other substance, which causes the body to react almost as if the substance is toxic. It might result in symptoms such as difficulty breathing, swelling of the tongue or lips, skin rashes or hives, swollen throat, water and itchy eyes, or even collapse. Common food allergens are eggs, nuts, milk and shellfish.
Delayed onset allergies (type 3 allergy often called food intolerances) involve an immune response (IgG antibody) and are a lot more common. The offending food causes a defense reaction by the immune system and if the food continues to be eaten the symptoms can be very unpleasant and quite serious, and may include chronic fatigue syndrome, asthma, irritable bowel syndrome, digestive problems such as bloating and stomach pains, headaches, skin conditions and unexplained weight gain, sore joints and depression
- Gluten intolerance – sensitivity to the protein components of some grain foods.
- Dairy intolerance – difficulty digesting dairy food due to a reaction to milk proteins.
There is another sort of allergy which involves a chemical reaction in the digestive system. These type of allergies are called pseudo allergies
- Lactose intolerance – problems digesting milk sugars due to low levels of the enzyme lactase.
- Histamine intolerance-problems digesting foods rich in histamine due to an enzyme deficiency
If you suffer from digestive problems, tests for food intolerance may be the best way to determine if you are indeed sensitive to certain foods that are causing your discomfort.