Just how accurate is the test?
This is the most important question of all and has several facets. 

Producer: Cambridge Nutritional Sciences is a vital part of the Omega Diagnostics Group and was a pioneer in developing consistent ELISA testing methods for food IgG antibodies. The Omega Group has a number 
of diagnostic platforms that detect IgG against foods; they are the largest provider of these tests worldwide. They use the same sources of purified antigens to make all these tests and they also validate the tests using the same large panel of patient blood samples before they are cleared for sale. While there is some inevitable slight variation by season in the exact mix of proteins contained in fresh raw foods, the same extracts are used across all test platforms.

Method: The ELISA (Enzyme-Linked ImmunoSorbent Assay) method is the diagnostic industry standard for antigen-antibody based screening tests. It is the most relied-upon technology for immunological testing in hospitals worldwide, including for life-critical blood tests such as HIV. 

Reproducibility of results: With the Food Detective, Cambridge Nutritional Sciences have produced the world’s only self-contained serum-antibody based food intolerance kit. Results with the Food Detective show a 95% correlation with results generated by laboratory testing.

Relevance of results: The gold-standard for demonstrating the value of a scientific intervention is the controlled double-blind clinical trial, This divides patients randomly into two groups. One group receives the real treatment; the other receives a sham intervention, To avoid bias, neither the patients nor the staff treating them are permitted to know which group they belong to. Unlike some tests purported to show food intolerances, food-IgG testing has been subjected to double-blind clinical trials, most notably in Irritable Bowel Syndrome, Migraines and Crohn's Disease. These hospital-based studies and were conducted by specialists in the relevant fields - most commonly Neurologists or Gastroenterologists. 

However, please note that there are things that IgG testing of this type will/can not tell you:
  • It does not test for food allergy. While the conditions might seem similar they are medically quite distinct. And the distinction is important. Food Allergy is pretty much a yes/no diagnosis. Food Intolerance is not. With intolerances, you may be able to tolerate rationed (with gaps) exposure to the problem foods. 
  • It does not tell you exactly how strong your intolerance is. Although all food-IgG tests (used for food intolerance treatment) can give a quantitative figure in your report, you still have to carry out the 12-week Elimination Diet (based on your test results) followed by careful Re-Challenge to get a good feel for how strong your intolerances are. 
  • It will not be able to tell you if your symptoms are perhaps equally influenced by other factors such as high sugar consumption, endocrine stress such as shift work - or inadequate sleep. Or by respiratory allergies to dust mites or dog hairs. When you decide to change your diet, why not give yourself the best chance and also work on your other lifestyle challenges?
  • It will not tell you why your immune system started to target harmless foods. IgG antibodies can be produced temporarily when you are exposed to a new food, as part of the acclimatization process. However, your immune system should quickly 'decide' that it faces no threat. We are not yet sure what tricks the body into producing more anti-food IgG antibodies - to the extent that they cause inflammation and symptoms. But we know the problem occurs much more in affluent countries. Professor Martie Truschnig at the Medical University of Graz in Austria has made a valuable contribution in examining food-IgG antibodies in obese adolescent children. She found they had higher amounts of these circulating IgG antibodies against foods and that the more they had the higher their levels of inflammation. While it may be tempting to view obesity as the cause, it is likely that it too is a symptom. 

If you have any of the following symptoms you could be suffering from food intolerance, especially if you notice a worsening after meals.

Food intolerance sufferers can also experience more than one symptom at the same time.

Attention Deficit
Bed wetting
Coeliac Disease
Chronic Fatigue
Cystic Fibrosis
Inflammatory Bowel
Irritable Bowel
Itchy skin problems
Sleep Disturbances
Water Retention
Weight Problems