Intolerance or allergy?

Food intolerances are sometimes confused with food allergies which are serious immune reactions to food (e.g. nut anaphylaxis). Common examples of intolerances include lactose, MSG and artificial preservatives.

Are over the counter food intolerance tests reliable?

Unfortunately, over-the-counter food intolerance tests are not reliable. Most of these products claim to test for multiple (up to 100) different food intolerances with a single test. The tests are based on the presence of IgG. IgG are antibodies made by our immune system and can be detected by a blood test. These tests claim that if you produce IgG in response to a food, it means that you are intolerant of that food. This is false information. We all make IgG antibodies to a food we have eaten. The presence of IgG is not an indicator of food intolerance or food allergy.

Other tests claiming to diagnose food intolerances include kinesiology, iridology, hair analysis and cytotoxic food testing. These tests do not have any supporting scientific evidence.

What to do if you think you have a food intolerance

Unfortunately, many people attempt elimination diets by themselves or on the advice of an alternative practitioner. Several foods are removed (e.g. gluten and diary being the most common) and there is no controlled reintroduction of the eliminated foods. This can lead to restrictive eating and in the case of diary removal – calcium deficiency.

If you are concerned you may have a food intolerance, you should see your doctor. If a food intolerance appears likely then you will be referred to a dietitian for a supervised elimination diet. An elimination diet should only be done under guidance of a dietitian or an immunologist.