Food allergy is a type I rapid immune response to consumption of a specific food to which a person has been previously sensitized to. It can be a very severe, life-threatening reaction that usually happens within minutes after eating the food, and involves IgE antibodies which trigger the release of histamine and other inflammatory factors following ingestion of the food allergen.
The most common food allergy signs and symptoms include Tingling or itching in the mouth. Hives, itching or eczema. Swelling of the lips, face, tongue, and throat or other parts of the body.
IgE Food Allergies affect a very small proportion of the population, although the number of people affected is increasing.
If you suspect you have a food allergy then it is important to seek urgent medical attention for it to be properly diagnosed.
Food Intolerances fall into two categories:
- Enzyme Deficiency – This does not involve the immune system, and is where insufficient production of an enzyme required to metabolise nutrients results in symptoms appearing following consumption of certain foods. For example, lactose intolerance is where a person does not produce sufficient lactase enzyme to break down and digest lactose which is a dairy sugar. This can lead to bloating, abdominal pain, diarrhea, and flatulence following consumption of dairy products. A Hydrogen Breath test can diagnose Lactose Intolerance.Histamine intolerance is another example and occurs when a person does not produce sufficient DAO enzyme to metabolise histamine from dietary sources, which can lead to itching, flushing, headaches, or urticaria
- Immune Mediated food protein intolerance. This is a delayed onset Type III immune response to consumption of specific proteins found in foods, which pass into the circulation as a result of impaired intestinal wall barrier. The immune system responds by producing food-specific IgG antibodies, which form immune complexes which can build up and deposit in tissues and joints. This results in an inflammatory response by the immune system, as it tries to break down these immune complexes which can exacerbate existing inflammatory disease, and which is associated with a number of chronic illnesses such as a Migraine, IBS, IBD, Obesity.IgG food intolerance is not life-threatening, and by identifying and eliminating trigger foods, studies show that symptoms usually improve within 3 months of elimination.