Frequently Asked Questions

Some foods may cause a classic allergic reaction involving the production of IgE antibodies (Type I allergy). These will not be detected by the GenArrayt® test as it detects IgG antibodies. There are also many foods that can cause a reaction in the body without involving the immune system, but produce symptoms similar to IgG reactions: amines found in chocolate, cheese and red wine may cause migraines; some food additives such as tartrazine, can trigger hives, rashes and asthma; monosodium glutamate (MSG) found in restaurant/take-away food can produce sweating and dizziness; ‘Nightshade’ alkaloids in potatoes, tomatoes and peppers may affect the joints. Food intolerance may also be due to a deficiency of a particular enzyme, such as in lactose intolerance. Avoid foods if you suspect they are causing adverse effects.

The GenArrayt® IgG antibody test is based on the immune system’s ability to produce antibodies in response to certain foods. If a food has been avoided for more than 3 months, it is likely that IgG antibody levels will be insufficient to be detected by the test and may give a NORMAL result. To test intolerance to a certain food, it should be included in the daily diet, or at least every other day, for 4-6 weeks before testing. However, if the food concerned is known to cause extreme symptoms/ discomfort, do not reintroduce it.

U/ml stands for ‘Units per millilitre’ and is a measure of concentration. The result for each food listed in the Test Report is expressed in U/ml, which shows the concentration of food IgG antibodies detected in the blood sample provided.
Once you have received the GenArrayt® test results, it is advisable to consult a nutritionist registered with the British Association for Applied Nutrition and Nutritional Therapy (, who can help advice on dietary changes and provide a supplement programme. They may also offer support and encouragement with regular progress checks, as it can be quite a daunting task to persevere with a new diet on your own.
No. Lactose intolerance is the inability to digest lactose, the major sugar found in milk, and is caused by a deficiency of the enzyme lactase. The GenArrayt® test detects IgG-mediated food intolerance caused by the specific proteins found in milk, but does not detect the lactase enzyme and, therefore, cannot diagnose lactose intolerance.
Yes, but we recommend a minimum age limit of 2 years.
No. A product can be wheat-free but not gluten-free and vice versa. Products are available that are both gluten-free and wheat-free, but it is important to read the ingredients label to be certain. The GenArrayt® IgG antibody test uses wheat, barley and rye food extracts that do not contain gluten and this is tested separately as gliadin (a storage protein found in gluten-based grains).

If your Test Report shows an ELEVATED reaction to gliadin, it is important to eliminate any foods that contain gluten-based grains and substitute with naturally gluten-free foods, such as quinoa, buckwheat, corn, oats and wild rice. If your Test Report shows an ELEVATED result for wheat, rye or barley, but NOT for gliadin, the reaction may be due to one of the other proteins found in the grains.

The GenArrayt® test uses water-soluble food extracts to detect food-specific IgG antibodies. Grain extracts, however, do not contain gliadin (gluten) because gliadin is only soluble in alcohol and cannot be extracted with the rest of the grain. For this reason, gliadin is tested separately.
Yes, so you should be careful when introducing a new dietary regime. We offer follow-up dietary
advice from qualified nutritionists to anyone who has taken the GenArrayt® test.
Most people do not need to have a re-test, but if you would like to take another test, we advise
a period of 6 months between tests. If symptoms have improved and you have successfully re-
introduced ‘problem’ foods, a re-test is unnecessary.
It is occasionally observed that patients react to foods that they are convinced they have never eaten. Although not unusual, it is not attributable to a false positive result, but instead a ‘cross-reaction’ with another food. Some foods contain identical antigens (food proteins), even though they are not related to each other and/or do not belong to the same food group. These identical food proteins will be detected by the same antibody, thus producing an ELEVATED result. Please contact CNS for further information regarding cross-reactions.
If, after changing your diet according to the test results, improvements have not been achieved after 3 months, food intolerance is unlikely to be the cause of your symptoms and other investigations should be undertaken. Results of the GenArrayt® IgG antibody test are intended as a guide to diet alteration only and should be complementary to advice from a healthcare professional.