Food Allergy vs Food Intolerance

Many people with “food allergy” reactions may not have an actual allergy but sensitivity to the food. A “true” allergy is an IgE immune reaction. These allergies affect two to three percent of the population and can result in symptoms such as rash or hives, and or as drastic as anaphylaxis where the mouth and tongue swell along with constriction of the airways. An IgE reaction is usually noticed very soon after consuming the food.

The most common allergy foods are peanuts, tree nuts, eggs, soy products, dairy, wheat, oranges, shellfish and fish.

Food intolerance or sensitivity is an IgG immune reaction. This is where IgG antibodies are created in the body after the protein in that food is recognised as an allergen or “enemy”.

Symptoms of food intolerances are wide and varied and can affect any of the body systems from digestive problems, skin problems, mood and behavior changes, respiratory reactions, muscle aches and pains and much more. Different from IgE reactions, IgG reactions can take some hours and sometimes up to a couple of days to surface which makes it even more difficult to determine without good food detective work.

Testing should start with IgE blood testing to rule out true allergies. Then a blood spot (finger prick collection) or serum (vein blood collection) test can be carried out for IgG reaction to foods.

Another type of test is ALCAT testing where the blood sample is exposed to various foods. The reaction of the white blood cells are noted and recorded. The more active the white blood cells are the more symptoms may occur in the body. This test reflects a reaction to the whole food and not just the protein.

At the end of the day, aside from IgE test results, the tests for food intolerances are there as a guide. For example you need to be eating a good range of foods leading up to intolerance testing for the test results to be as accurate as possible. If for example you haven’t eaten a food for some time, that food unlikely to present as an intolerance during the test because the body would not be recognising it as a problem.

Food intolerance testing in its various forms is very helpful in pinpointing problem foods from the outset. This approach along with food diary recording is excellent for spotting problem foods or drinks to speed your way to better health.

By Jan Purser

Naturopathic Nutritionist