Food intolerances are common reactions to food that are not
life threatening. They often cause bloating, irritable bowel symptoms,
headaches, rashes and increased mucous production.
It can be difficult to work out which food is causing your
symptoms, but how reliable are the food intolerance tests?
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.
