by Erin Child
So, you think you have a food intolerance? What do you do? You could call your doctor and set-up an appointment that is inevitably months away. Then you have a 10-minute meeting in which they only look at their computer and refer you to a specialist, THEN go through more testing, and finally (hopefully!) get some answers. Or, you could order an at-home kit that takes 10 minutes to complete and promises results that will get you feeling better, sooner. Which one do you choose? Read on and decide.
In our current world of food intolerances and hypersensitivities in which the best path to treatment is often a conundrum, the Pinnertest promises an easy solution to any dietary woes. A few months ago, I started noticing ads for this new test popping up on social media. The Pinnertest is an over-the-counter food intolerance testing kit that uses microarray technology to test for IgG (Immunoglobulin G) mediated sensitivities for 200 common foods.
The classic manifestations of true food allergies (hives, oral discomfort, trouble breathing, anaphylaxis, etc) are mediated by overproduction of IgE antibodies. Like IgE, IgG is a type of antibody. And IgG is the most common antibody in the human body. (The immune system releases five types of antibodies: IgA, IgE, IgG, IgD, and IgM.) Instead of testing IgE mediated allergies, the Pinnertest producers claim that the microarray technology allows them to test for IgG mediated intolerances to 200 different foods—including lettuce, quail, and baking powder—using only a few drops of blood. It sounds scientific, but also seemed too good to be true. Was it?
I started my research by reaching out to the Pinnertest folks directly. My goal? To score a pro-bono test to try it out myself and see the results first hand. I was thrilled when a friendly representative at Pinner immediately reached out to set up a phone interview (calendar evite and everything). When the day came, I called—and was sent to voicemail. Twenty minutes and five tries later, I knew I had been ghosted. My subsequent emails were ignored, and my quest to learn first-hand about the scientific evidence backing their product was squashed.
So, I began researching on my own. The Pinnertest website sports a cluttered page of medical study citations that cover work on food allergies, intolerances and Celiac Disease—but none of which provide any evidence of using IgG testing for food intolerances. My own PubMed search [IgG + food intolerance; Immunoglobulin G + food intolerance] yielded little, but did include one recently retracted 2016 article linking IgG testing to food allergies. The rest of the Pinnertest website leads you down a rabbit-hole of B-list celebrity endorsements and every Friedman student’s favorite—Dr. Oz videos! Interestingly, nowhere on the site does it tell you the cost of the test. To find out pricing, you must first enter your information (“Hi, my name is Newt Trition”) before you discover that the test will run you a whopping $490.
To further explore if this test has any scientific merit, and is worth the hefty price tag, I reached out the Boston Food Allergy Center (BFAC). Dr. John Leung, MD, the founder and CEO of the BFAC, and the Director of the Food Allergy Center at Tufts Medical Center and Co-Director of the Food Allergy Center at Floating Hospital for Children, took some time out of his day to answer my questions. Dr. Leung said, “We have patients coming into our office on a weekly basis with that kind of report [IgG], who pay out of pocket no matter what insurance they have. [Insurance doesn’t cover the test] because there is a statement from both the American and European Societies for Allergy saying that this test has no clinical significance.”
This is something to consider in any area of medicine—if a test is not covered by insurance, it may be the first sign that clinical significance could be lacking.
My conversation with Dr. Leung was brisk, informative, and confirmed my gut reaction that this test was too good to be true. Furthermore, there is a body of literature providing evidence that IgG mediated reactions are a sign that a food intolerance does not exist, not the other way around. In a 2008 European Academy of Allergy and Clinical (EAACI) Task Force Report, the authors wrote, “food-specific IgG4 does not indicate (imminent) food allergy or intolerance, but rather a physiological response of the immune system after exposition to food components.” Simply put, IgG evidence can show that you’ve been eating that food, not that you are intolerant to it. The EAACI has been joined by their Canadian, American, and South African counterparts in clear statements that research does not support the use of IgG mediated testing for food intolerances at this time.
Having shadowed Dr. Leung at the BFAC, I know that he takes patients’ claims of food intolerances seriously, and is invested in using the best clinical practices and scientific evidence available to make the diagnosis. Concerning IgG mediated testing, he stated, “There is so little research, so from a clinical view it is not very useful, it doesn’t mean much. It is not diagnostic.” And yet, the Pinnertest website claims that the“Pinnertest is a common procedure in most European countries. In many cases, dietitians and nutritionists will ask for their client’s Pinnertest results before creating any kind of diet plan.” Since this approach directly contradicts the current EAACI recommendation, that’s highly unlikely.
I also had the opportunity to speak with Rachel Wilkinson, MS, RD, LDN, and Practice Manager of the BFAC. Rachel explained, “If patients come in concerned about food intolerances, we can do the hydrogen breath test for lactose, fructose or fructan [found in some vegetables, fruits and grains]. These are the three main ones [food intolerances] we can test for, because we actually have tests for those.” She went on to state, “What was interesting to me about the Pinnertest, was how they say they can specify one specific food–so not just a category. I honestly don’t understand how they would pinpoint a specific food. It makes more sense to me to listen to patient’s histories and to look at how their intestines are able to break down that particular group of sugars. So, I really would love to know how they [Pinnertest] are coming up with this.”
It is important to note that the Pinnertest is not just marketing itself as a food intolerance test. It is also presenting itself as a weight loss tool. Current Frances Stern Dietetic Intern and Masters Candidate Jocelyn Brault, interning at BFAC, indicated her concern: “I think this is also being marketed for weight loss, which you can see throughout their website. This is usually a good sign that we should dig deeper. Is this a proven weight loss method? This claim seemed out of nowhere to me.” Indeed, directly on the Pinnertest box it reads, “Discover which foods are making you sick or overweight.” If taken seriously, this test will result in unnecessary diet restrictions, and potential malnutrition if too many foods are unnecessarily eliminated. Rachel Wilkinson, RD noted, “if you’re going to be avoiding certain types of foods, you need to make sure your diet is still adequate. We do not want to see people over-restricting foods for no reason.”
Over the course of my research and conversations with Dr. Leung, Rachel, and Jocelyn, I confirmed that my initial gut reaction was correct: too good to be true. And here’s the kicker, so does The Pinnertest. In a tiny disclaimer at the bottom of their website, they write: “Quantification of specific IgE antibodies to foods and inhalants is an FDA-accepted diagnostic procedure for the assessment of allergies. However, the assessment of human IgG antibodies specific for individual food and inhalant antigens is not an FDA-recognized diagnostic indicator of allergy.”
It is a noble task to try to design an allergy test that does not require you to doctor hop, or wait months for an appointment, but the scientific evidence needed to back up the Pinnertest is lacking. Perhaps one day this will shift, and the body of evidence will improve. In the meantime, however, anyone who thinks they might have a food intolerance (or food allergy) is best served by going to their clinician (and then a dietitian). This at-home kit promises a quick fix, but is really just an expensive, dangerous distraction.
Erin Child is a second-semester NICBC student in the dual MS-DPD program. She is fascinated by the science of food allergy and intolerances, and will probably keep writing about them until someone tells her to stop. With two weeks left in the semester, she would really like a nap. Like right now.