Recently, CBC Marketplace aired a segment that blasted the use of IgG food sensitivity tests as a tool in overall health. The segment had two experts in their segment that deemed the test as "unsafe," saying people should actually MORE of the food that comes up in their results to build a better immune system.
I am not a doctor, but I believe whole heartedly in food sensitivity testing - and temporarily avoiding what comes up. I see results personally and professionally.
Most major labs in North America offer IgG testing, and it is used by numerous health professionals in Canada, including physicians, naturopathic doctors and nutritionists as a tool in developing a customized health plan. In fact, my mainstream family MD recognizes results, as does the functional MD who treats my daughter for her autoimmune condition. Yet, our paediatrician does not.
It's confusing. Who should you believe?
The immune system is complex. As a holistic nutritionist, I can only provide my basic understanding. And you should absolutely listen to the advice of your doctor or another credible health care professional when considering any sort of testing. Do your research. Make smart, informed decisions.
Consider this article "food for thought" as you weigh options.
What is IgG testing?
In short, a food sensitivity test measures the amount of immunglobulin G (an antibody - a "fighter that protects your body") in response to an antigen (an antagonist, a foreign invader the body doesn't recognize or perceives as a threat).
What does that mean?
"When your body feels it is under attack, it makes special proteins called immunoglobulins or antibodies. These antibodies are made by the plasma cells. They are let loose throughout the body to help kill antigens like bacteria, viruses, and other germs. The body makes 5 major types of immunoglobulins:
Immunoglobulin A (IgA)
Immunoglobulin D (IgD)
Immunoglobulin E (IgE)
Immunoglobulin G (IgG)
Immunoglobulin M (IgM)
Immunoglobulin G (IgG) is the most common type... IgG is always there to help prevent infections. It’s also ready to multiply and attack when foreign substances get into the body." John Hopkins Medicine on IgG deficiency and why it's important to have IgG antibodies in your system.
So, our bodies produce antibodies - immunoglobulins - as a protective mechanism against foreign invaders.
When someone has an allergy (food, animals, environment, chemical), there is an immediate and measurable immune response. The most common immunoglobulin measured is IgE. When there is an IgE response, typically, your response is fixed - it is there for life, or at least a long period of time. An IgE reaction indicates a systemic immune response to the invader (like anaphylaxis, asthma, runny nose, itchy eyes, dermatitis). Other immunoglobulins are sometimes measured (like IgA - the mucous response), but IgE is the most common one measured when you visit an allergist.
To diagnose allergies, the most common test is the "scratch test" whereby the allergist pricks the skin, allowing a small amount of a protein to enter the blood stream. The reaction is always to the protein in the food or substance, and immediate - usually 15 minutes. Doctors diagnose allergies by this reaction - redness, swelling, itch. Doctors will sometimes use blood tests, when a skin test is deemed too dangerous (skin infection).
This test is important and can save lives. In the case of anaphylaxis (a life threatening allergy), allergists are a key part of the team. In no way do I mean to discredit the profession.
My understanding is that "allergies" that mark an IgE response are typically fixed - meaning there's a good chance you have them for life. I have lots of fixed allergies. But I also have lots of IgG responses (food sensitivities), which I will get into next.
I've asked three allergists about IgG testing (two of mine and one for my daughter), and they have told me time-after-time that this test is unreliable because I can have a positive reaction one test and negative the next test. There is no concrete, set-in-stone, quick reaction. They have also told me the scratch tests for food are sometimes unreliable - doctors don't like performing them.
So, let's look at my personal experience.
I have seen allergists all my life - repeatedly, some years. And they have been helpful and improved my quality of life in various ways. I have always been extremely allergic to cats, dogs, mold, horses, rabbits and birch trees. I've had shots, sprays and pills which have helped make the allergies more bearable. But, they are still there. In fact, if you want to kill me, lock me in a closet with a cat and I'll be dead in two days. My environmental allergies have never gone away.
I've also been told over the years that I also have food allergies. Some of the diagnosed food allergies of my childhood have gone away. Peas, peanuts, oats and oranges were high when I was young, but don't show up any more. My most recent visit to the allergist (2016) didn't show any of these foods. This was good news. The doctor said I was no longer allergic. When I asked why they went away - I thought they were fixed - I was told "food allergy tests can be misleading and perhaps you have built up an immunity."
HOWEVER, she handed me an epipen for a new hazelnut allergy, something I didn't have before. She reluctantly tested for nuts because I insisted that "mixed nuts" made my mouth itch. She was also unable to explain why at the age of 45 my other food allergies had gone away and why I had this new and potentially, life threatening one.
I asked specifically about gluten and dairy. Am I allergic to those foods? Why did I break out in eczema and had ulcers in my mouth when I ate dairy or wheat? She didn't have a response because I didn't show a response to those foods with the scratch test. She said I was not allergic.
I was thankful that we figured the hazelnut thing out, but left my appointment confused.
What is a food sensitivity test?
This past summer, I did a food sensitivity test with Rocky Mountain Analytical - the facility we work with at our clinic. A food sensitivity test marks your body's IgG response to 200 tested foods. Remember, an IgG is a reaction to a perceived threat. This was the subject of the CBC segment.
You give a vial of blood at a blood lab and the lab marks the IgG response to proteins in 200 common foods.
The results allocate a colour scheme to the tested foods along with a number score. The foods in red should be avoided, yellow in moderation and green, no worries. The marking scheme is based on the IgG response. The lab report also provides pages of helpful information (how to substitute, etc.).
I get my report back. Remember those foods that were "fixed" when I was young and disappeared as an adult? Well, some showed up on that list, as did some new foods - almonds, Brazil nuts, flax, sunflower seeds and others. So, according to the food sensitivity test, I'm still reacting to some of my previous allergies and now reacting to more nuts than simply hazelnuts.
Wheat and dairy were also there. But according to the allergist, I'm not allergic to wheat or dairy, despite the eczema and ulcer connection.
I'm given an epipen for a hazelnut allergy (a tree nut) that makes my mouth itch. I break out in eczema and get ulcers in my mouth when I eat wheat and dairy, but I'm not allergic. And if I listen to the CBC report, I should eat MORE of my food sensitivities - tree nuts, wheat and dairy - despite my hazel nut allergy, ulcers and eczema.
Why I recommend food sensitivity tests
According to allergists, IgG testing does not identify fixed immune responses and they do not consider them allergies. Reactions can ebb and flow. In fact, the allergist in the CBC segment recommends that we eat MORE of these foods to build up an immunity to them.
So, the allergist recognizes there is a reaction. The confusing part is the "holistic world" and the medical world differ on how to address. One stream says "eat more" and the other says "eat less."
From my perspective, depending on your state of health, you can have heightened sensitivity to what is entering your body.
State of mind, chronic inflammation, stress, physical injury, toxic overload, leaky gut and bacterial imbalances can all negatively influence your body's immune response. Hundreds of books have been written on this subject by various inflammatory experts - MDs and NDs alike.
This is a very simplified summary.
When you are in a state of good health, your body is better able to process a wide variety of foods with little effort. This is no different than being able to fight off a cold/flu that is going around. However, when you are have chronic, lingering health issues, you might react to certain foods that wouldn't normally bother you.
Remember, 70% of your immune system is found in your gut. I think it's safe to say that if your gut isn't in good health, your immune system may be compromised and not behaving the way it should.
I recommend food sensitivity tests when I know you have already done some work to clean up your liver and gut, and there are still underlying issues:
There are chronic symptoms/issues you can't get rid of (excess weight, constipation/diarrhea, nasal/cough, brain fog, migraines)
You have odd reactions to foods and aren't able to pinpoint what food is bothering you
There is a medical condition you want to proactively prevent or overcome
You have skin issues (eczema, rosacea, psoriasis)
Anxiety/learning/attention condition is negatively impacting your life
The reason why I recommend food sensitivity tests under these situations is to eliminate any possible external triggers - exterior irritants - that may cause an additional inflammatory response. The goal is to let the body CALM DOWN. Reduce overall inflammation so your body can focus on healing and return to balance.
Make sense? It does when you consider the role of IgG - to defend the body against against what it perceives as foreign invaders.
The usual protocol is to remove these foods for three to four months, during which time you really make an effort to reduce internal inflammation. For some that may mean herbs to address bacterial imbalances. For others that could mean starting a new supplement regime to address your key health concern. You then reintroduce one food at a time to see if your body still reacts.
Reactions can take up to four days, so it's important you REALLY pay attention to how you feel - physically and emotionally. It can vary from person to person. Here is a short list of possible reactions
Skin: itchy, dry skin, eczema flare, hives
Brain: fog, irritability, mood swings, difficulty concentrating, hyperactivity
Digestion: constipation, diarrhea, stomach pains, gas/burping
If you are still reacting, we remove the trigger food for another few months, and so on. The goal is to get you back on track, eating all the foods you want to enjoy. However, unless the underlying reason as to WHY there is inflammation is not resolved, the food sensitives may linger. The process is not black and white. It's individualized and a journey.
In my case, I have been reacting to gluten and dairy for a few years. This summer, I tested positive for the primary celiac gene in addition to an IgG sensitivity. It is not a diagnosis for celiac, but given the fact I get mouth ulcers and eczema, all doctors since have unanimously advised I stay away. Here, it is worth noting that the protein in wheat and dairy are very similar size and shape (it is very easy for the body to get confused between the two and attack both).
This is where the CBC segment really missed the mark. They looked only at the test and not the application or individualized approach. Nor did they address the many root issues as to WHY a person would be reacting to foods and HOW to go about bringing things into balance. That doesn't fit into a 10 minute segment or sell advertising.
Living and working around food allergies or sensitivities doesn't have to be limiting. Many of my clients panic when we look at food sensitivity test results, but once they realize, "hey, there are lots of great things I can eat," and I give them tools to cope, AND they start FEELING BETTER, they typically handle it with ease.
The good news is that there are so many options and substitutions you can draw on. I encourage you not to dismiss food sensitivity testing if you have a chronic health issue based on this one CBC report. The results can be helpful and liberating in your overall health plan.