Guest Post by Dr. Kellie Ferguson: Food Sensitivity Testing – Let’s Talk About Your Options!
Allow me to introduce Dr. Kellie Ferguson, N.D., a Naturopathic Physician in British Columbia, Canada. Kellie is actually a very old friend of mine–we went to high school together! But don’t worry; neither one of us remembers high school so no embarrassing stories can be told. I asked Kellie to give an overview of food sensitivity testing since this is so relevant for anyone battling autoimmune conditions, non-autoimmune skin conditions, gastrointestinal disease, and allergies. It is a particularly important option to consider for anyone following the autoimmune protocol and not seeing improvement. You can read more about Kellie’s practice at her website www.koruhealth.com and her blog www.koruhealth.blogspot.ca.
As promised in my last guest post, today I’ll give you a little more information about testing for Food Sensitivities. Just to backtrack a little, food sensitivities happen when the body reacts to proteins in specific foods and the immune system is activated by those proteins in much the same way as it is activated by proteins on bacteria. A reaction is mounted by the immune system and can cause inflammation both at the gut level and systemically throughout the whole body. Because of the complexity of the immune reaction, food sensitivities are often one of the key underlying triggers for many different complaints. I almost always think about them when dealing with three key complaints including: skin conditions like eczema or psoriasis, GI upset including anything from heartburn to diarrhea, and behavior difficulties in kids (ADHD, temper or Autism Spectrum Disorder). Also, many people with autoimmune disorders, arthritis or migraine benefit from knowing if there are any food triggers aggravating their symptoms.
So we know it’s important to check for food sensitivities but how do you do it? There are three different testing choices available to identify food sensitivities. Please note, that food sensitivities are very different from food allergies and the following testing methods are not adequate to diagnose food allergies. The gold standard is a physician controlled Elimination and Challenge test. In this case, we limit the diet to a very restricted set of hypo-allergenic foods (usually foods that are outside the normal diet) for a good period of time (usually 3-6 weeks) and then challenge with each food, generally in a medically controlled environment. The goal is to allow the body a chance to heal up as we take away any provoking foods and then we slowly add each single food type one at a time and gauge for reactions. For example, we might do our elimination for 3 weeks and eat only lamb, pear and brown rice, then introduce dairy products for a few days while we watch for skin or tummy symptoms. This type of diet needs a lot of planning and commitment and, because the elimination diet is so limited, it should not be done without the supervision of a qualified practitioner. It should be mentioned that challenging with foods can cause quite pronounced reactions with asthma or serious autoimmune conditions and should be done exceptionally carefully (and only with medical supervision).
The next type of testing is called EAV testing, which is also known as Biomeridian or VEGA testing. This testing uses an electronic tool to evaluate the energy in specific acupuncture meridians and how that energy reacts when challenged with foods. It sounds a little odd but is really very effective for many complaints. The advantage to this is that it can be done quickly and in-office and is non invasive. It does require that the patient be able to sit relatively still for a period of time, so it can be difficult with younger kids or kids with restlessness/hyperactivity. It is also fairly specialized and difficult to do well, so I always suggest asking lots of questions of the practitioner first. A variation of this type of testing is called muscle energy testing, which measures muscle strength when foods or supplements are held close to the body. Both types of testing measure the body’s energetic reaction to the foods. Muscle energy testing is quick and easy but can be easily manipulated by the tester or the patient (as can EAV testing, though to a lesser degree). It is really important that the tester be really careful not to allow his or her bias to influence the results. This is partly why this type of energetic testing isn’t well accepted by conventional medical practitioners.
The last type of testing, and the only one that can allow us some information about food allergies, is called ELISA testing. ELISA testing measures how much (if any) of an antibody (immune) reaction there are to specific food proteins. Before we get into the specifics of this test it’s worth talking a little about the different types of antibodies and their immune reactions. Antibodies are little proteins, made by the immune system, that tag and attach to foreign proteins (food proteins, bacterial, viral or parasite proteins) and signal for inflammatory or other immune processes. There are several classes of antibodies but there are only three that are relevant for food testing. IgG is the most commonly tested antibody for food sensitivities since is the most abundant and long lasting antibody. Total IgG is used to give a broad view of the overall immune sensitivity reaction, however any positive results need to be interpreted given the individual and the diet and target symptoms as there are often many mild positive reactions that do not provoke symptoms. IgE is specific to allergy reactions but not sensitivities. IgE proteins have a very short life and are much more difficult to test, so the number of foods tested is generally limited to most common allergens and must be done through a blood draw. IgE testing is sometimes done with a slightly different test called a RAST test. This test is almost identical to ELISA but has a slightly different procedure in the testing laboratory. The final antibody that can be relevant is IgA. IgA is the only antibody that gets secreted into the digestive fluids and so is very specific to digestive sensitivity symptoms. It is possible to have IgG be negative for some food reactions but positive IgA or vica versa. Your Naturopathic Physician should be able to discuss all the testing options and help you to choose the best type or combination of testing for your symptoms and budget.
There are many lab companies in North America that offer antibody testing and they have widely variable pricing and reliability of their tests. Most have different food lists available that can be chosen specific for the patient’s needs (ie. vegetarian panels or specific IgE, IgG or IgA tests). This testing does require a blood sample, and depending on the type of tests, it is either with an arm drawn sample or a dried blood spot taken using a finger stick. Most kids find the finger prick quick and easy enough that they don’t complain… at least not much.
For patients coming into my office, I always suggest we discuss their complaints and talk about the testing options to figure out which, if any, is the best choice. The best option might depend on your financial situation, time goals and the condition itself. Most Naturopathic Physicians have done a good investigation into the testing options available in your area and can give you good guidance. It also takes experience and finesse to decide how to incorporate the results into a reasonable diet plan, which licensed Naturopathic Physicians will have. Most testing methods will show that there are many reactions, most of which are fairly mild. It’s not reasonable or necessary to completely eliminate all those items. The practitioner’s experience will help to show which foods are not generally significant triggers and which can be common suspects and how to tell the difference. Reactions that are really strong should be avoided completely. Other food reactions are mild but cumulative and their symptoms will depend on the amount and frequency of their exposures. Eating small amounts of those foods only a couple of times a week won’t be an issue but a big serving or using it as a staple in your diet will start to trigger symptoms. I generally start with IgG finger stick testing, as the company I use has excellent pricing and turn-around time and has a choice for an expanded panel with many extra spices and foods. I find that this provides the most information at a reasonable cost and can be interpreted well given the patient history and symptoms.
To find a Naturopathic Physician in Canada go to http://www.cand.ca/index.php?findnd&L=0 to find one in the US try http://www.naturopathic.org/AF_MemberDirectory.asp?version=1 . If you have any questions or comments please feel free to email or post via my blog, where you can also find more tips about current news topics, allergies, Autism and other Naturopathic topics.