Food Intolerance Tests Don’t Work

Food Intolerance Testing

When you visit us for any skin related concerns, you’ll need to complete a, skin consultation is a must. We work holistically (outside in, inside out approach) so there will be many questions relating to diet, nutrition and general lifestyle. It’s important we have an understanding of this information otherwise we could be missing a key bit of information when prescribing treatments and products.

We need to make it very clear – we are not dietitians, nutrionists or naturopaths and don’t claim to be. Having said that, we take a big interest in internal health and well-being given the link between gut health and the skin (it would be unprofessional to ignore this). While we may be able to identify potential contributors to skin conditions, it is outside our scope of practice to assume we can fix or remedy those internal issues. We will always refer you to a qualified medical professional or nutritional practitioner.

For this reason, we do dedicate a bit of time to what’s happening in the nutrition industry – it’s in our best interests considering both the skin and nutrition/gut health is often be very closely linked.

We recently came across some information from a highly credible source that debunked pretty much every food intolerance test out there. In short – food intolerance tests are garbage and can provide seriously inconsistent, misleading and incorrect information.

So we decided to do a little more research into food intolerance testing and the source was absolutely spot on. Food intolerance testing has some major flaws and the companies manufacturing and selling them appear to be well aware of it (though it still doesn’t stop them). Worse still, and quite disturbingly, there are actually some qualified practitioners out there also using them.

Various methods such as cytotoxic food testing, Vega testing, kinesiology, iridology, pulse testing, Alcat testing, Rinkel’s intradermal skin testing, reflexology, hair analysis and IgG testing, have all been ‘proposed’ as being useful for diagnosing allergic conditions or food intolerances. Unfortunately, all these tests lack scientific rationale and have been shown to be inaccurate and poorly reproducible when subjected to careful study. Treatments based on inaccurate results is misleading and can result in ineffective and sometimes harmful treatments, not to mention delay more effective therapy.

If you would like to read more about these individual tests, you can head on over to here or here!

IgG Testing

While there are many tests, one of the most common is an (Immunoglobulin G) IgG test. Some of these claim to test for almost three hundred different foods using a drop of your blood. The cost? It’s usually in the hundreds!

The claim is that if you’re allergic or intolerant to a particular food, you’ll have certain antibodies which can be detected in the test and it will also tell you the degree to which you’re sensitive.

While IgG does play a role in allergic response, the tests don’t provide anything useful. The antibodies detected simply reflect what you’ve eaten (exposure rather than intolerance). For people who are growing out of allergies – which happens in kids especially – the level of IgG antibodies goes up (tolerance).

Tests have found that people with known genuine intolerances, proven by elimination diet and oral challenge, don’t show raised IgG antibodies.

According to ASCIA:

“there is no credible evidence that measuring IgG antibodies is useful for diagnosing food allergy or intolerance, nor that IgG antibodies cause symptoms”.

Major allergy and immunology organisations worldwide advise against IgG testing.

Gold Standard Testing

The only reliable way to determine intolerance is by being placed on a temporary elimination diet under the supervision of a medical practitioner such as an immunologist or allergist. If removing the food from the diet helps, this is followed by challenges under controlled conditions to identify triggers.

It is important to emphasise that elimination diets must only be undertaken for a short term, under strict medical supervision. Prolonged restricted diets can lead to further problems, particularly in children.

These tests are, as you might imagine, extremely time consuming for all involved – patient and practitioner alike – and elimination/challenge diets require a high degree of motivation and compliance.

For this reason, it obviously makes a simple blood test that you can buy online much more appealing. The issue here is that you’re paying for something that has very little (no) credible literature or scientific evidence supporting the results. What you essentially get is the most exspensive piece of paper you’ll probably ever own – that’s worth absolutely nothing!

Food Intolerance vs. Food Allergy

A food intolerance should not be confused with a food allergy.

food allergy involves the immune system, and happens when the body reacts to a protein in specific foods, which are usually harmless. Reactions are usually immediate and can occur after being exposed to very small amounts of the food.

The most common food allergies include eggs, peanuts, soy, milk, wheat, fish and shellfish.

Food allergies can affect around one in 20 children, and two in 100 adults. Up to 10% of babies may suffer from food allergies, but most of these will grow out of the allergy early in life.

Food intolerance, on the other hand, is a chemical reaction, and does not involve the immune system. They can be in response to some of the naturally occurring chemicals in food and to common food additives such as preservatives, artificial colours and flavourings. Reactions are dose dependent and different people will tolerate different amounts of any given chemical.


Based on all the evidence we’ve come across so far, we would strongly recommend that you do NOT have these tests done. Save your time and money. INVALID intolerance tests may lead to nutrition deficiencies, high levels of anxiety & eating disorders.

There is currently no reliable and validated clinical tests for the diagnosis of food intolerance. The tests lack both scientific rationale and evidence of effectiveness. The lack of correlation between results and actual symptoms, and the risks resulting from unnecessary food avoidance, only escalate the potential for harm.

Get the test done properly and correctly by an immunologist or allergist that can document your history and then use a combination of skin prick testing, allergen-specific IgE blood testing and oral food challenges under controlled conditions.

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