Testing for Food Sensitivities
First of all food sensitivity is not the same as food allergy. Food allergy involves the immunoglobulin E (IgE). To determine food allergy that creates various degree of anaphylaxis, check with your family doctor to get a referral to an allergist.
Food sensitivity is a milder and more chronic immunological reaction that can have effects throughout the body. Whenever you consume a food that your body is sensitive to, your body has an immunological reaction. Based on my practive experience, the reaction can be as minor as a postnasal drip (just like your postnasal drip during a cold) or as severe as autoimmune symptoms.
Choosing a food sensitivity testing is a difficult task these days, given the number of tests available. Not all tests are created equal, of course.
The earliest food sensitivity testing were the electro-dermal screenings. This involves a seated patient being connected to a machine by one hand while holding onto a potential food/chemical sensitivity in the other. The operator then applies a mild pressure and electrical current through a stylus to various energy points on the patient. The machine then reads the electrical conductivity to determine if the patient is sensitive to a particular material. It sounds like witch craft, but done by a skilled practitioner, can yield useful information. Unfortunately, there are many unskilled practitioners out there so the test is not always reliable.
Then came the IgG (immunoglobulin G) tests. IgG, and other immunoglogulins, are compounds produced by white blood cell in response to something foreign. It is a by-product of an immune reaction. The IgG food sensitivity test is a scientific tool that has helped many people over the years. You will most likely find this test at your naturopath’s office and at the local chain pharmacies. The process involves collecting a few drops of blood on a test patch/strip. The blood is allowed to dry before shipping off to a near by lab. Once at the lab, they expose potential food antigens to your blood sample. If your blood binds to the sample, then your body has an immune recognition of the food, a food sensitivity. This is an ideal test for individuals with needle phobia or people with bad veins. The weakness to the test is due to the fact that your body is always getting rid of old IgG. So if you have not consumed a particular food in awhile, or not in sufficient quantity, then the IgG testing will not yield a significant reactions. In other words, if you are sensitive to strawberries but you have not eaten it since the summer. A test done in December may falsely give you a “mild” or “no reaction” to strawberries. The only way to do a good IgG test is to eat large quantity of all the foods being tested 1-2 week prior to testing. As a result, you can only accurately test a small number of foods at any given time. There are tests that offer to check for hundreds of food antigens at once. These tests cannot yield reliable result even if the hefty price may suggest otherwise.
Having tried many foods sensitivity tests myself, my favorite is the whole white blood cell test. For this test, vials of blood are collected from the veins and shipped off to the lab immediately. At the lab, the white blood cell is separated from the rest of the blood and exposed to food/chemical being tested. The white blood cells’ reaction is then observed. So instead of trying to determine what the patient might be sensitive to through “hear say,” we get the info straight from the horse’s mouth. The benefit of this test is the patient will not have to do any prep work prior to the testing. As well, we can test for large number of food and chemicals in one test with accuracy. The down side to this test is the blood draw.
Before getting a food sensitivity testing done, you may have to change your medication regiments for a few days. Some medication will interfere with the different tests. Speak to a qualified professional about what is acceptable.