Written by dietetic intern Kylee Henschel and Orli Rabin of ThrivingBiome
Over the past few years, the term "food sensitivity" has skyrocketed in popularity, with more people attributing gut issues, bloating, fatigue, and other unexplained symptoms to certain foods. As a result, many self-diagnose and eliminate foods in an attempt to find relief. Often, these people do not fully understand what food sensitivity actually is. With food sensitivities becoming a go-to explanation for digestive discomfort, how can we tell if we’re truly sensitive to a food, or if something else is at play?
One common misconception is that food sensitivities, food intolerances, and food allergies are interchangeable. In reality, these are three completely different reactions to food. The distinction is critical to make because symptoms can range from slightly discomforting to life-threatening. A food allergy is the most dangerous of the three. It occurs when your body creates an immune response against a certain food because it mistakenly thinks it will harm you to digest. Consuming this allergen can lead to symptoms like hives, swelling, and a potentially fatal anaphylactic shock. A food intolerance, on the other hand, refers to the inability to digest a certain food. It occurs due to a lack of sufficient enzymes, which help break down foods. A common form of this is lactose intolerance, caused by insufficient lactase enzyme and an inability to digest lactose. Symptoms most commonly include GI discomfort like gas, bloating, and diarrhea.
Unlike food allergies and intolerances, food sensitivities are complex and hard to define. They do not create a clear immune reaction in the body like allergies, and they also do not stem from enzyme deficiencies preventing proper digestion. Food sensitivities involve a wide range of symptoms and individualized triggers, making them tricky to pinpoint and understand. Despite research attempts, there is still controversy over the specific mechanisms of food sensitivities. Symptoms like stomach pain, joint pain, rashes, diarrhea, etc., which are not attributed to an allergy or intolerance, are considered food sensitivities.
What is Food Sensitivity Testing?
Many people turn to food sensitivity testing to get answers about their food-related symptoms. However, with the exact cause of food sensitivities still a mystery, do these tests actually work?
To answer this question, let's dive into how testing is done. You may have seen ads for popular food sensitivity tests like Yorktest or Everlywell, marketed to help resolve your chronic gut symptoms. These companies collect finger-prick blood samples that you can mail directly from your home. The labs examine IgG reactivity to see responses to different foods. IgG is a type of protein in your blood called an antibody that helps your body fight germs and remember things it has seen before, like foods or infections. The idea is that a higher IgG response indicates a greater immune response, and a higher sensitivity to that food. Sounds promising, right? The issue is, IgG is a memory antibody. Production is a normal part of the immune response, and when someone eats a food, they will naturally produce more antibodies toward that food. Additionally, if someone’s gut health is compromised, like in people with intestinal permeability, more and more foods could eventually cause an IgG antibody reaction. Given all of this, these tests can be unreliable, giving false positives and negatives. Watch this video from Doctor Mike for a more in-depth explanation of how food sensitivity testing works!
Should I Test?
In short, we do not recommend joining the bandwagon of food sensitivity testing. These tests are unreliable and based on antibodies, which are part of a healthy immune response. They often lead to unnecessary restrictive diets and potential nutrient deficiencies. Not to mention, they are pricey to order!
What can I do instead?
There are options for testing that do not merely look at IgG antibody response. In general, MRT testing is best for detecting food intolerances and certain gut panels, such as the GI-MAP, can provide us with information about gluten sensitivity through its detection of anti-gliadin antibodies in the stool. MRT testing is a form of food sensitivity testing which captures ALL types of food sensitivity reactions by indirectly measuring the release of inflammatory chemicals called mediators. It’s the release of these mediators that cause symptoms of food sensitivities, not necessarily IgG antibodies. If you decide to pursue food sensitivity testing in the future, ordering an MRT test through a LEAP certified registered dietitian is the best option. However, this test is still not 100% reliable for detecting food sensitivities, and needs more research for validation. The gold standard for detecting food sensitivities continues to be elimination diets paired with careful reintroduction of foods. While this is a time-consuming and many times hard process, it allows you to experience which foods are causing your symptoms first-hand.
If you suspect that you have a potential food allergy (different from a sensitivity), there are reliable tests offered at the doctor's office. Typically, you will receive a skin prick test. This test works by pricking extracts of potential allergens lightly into your skin and watching for a reaction. The formation of a red, itchy bump at any of the pricked sites indicates an allergic reaction to that substance. This may sound scary, but it’s not a painful process. It feels like a scratch or pinch of your skin and you will be in and out of the office in under an hour. As many as 50 allergens can be tested this way at once! Unfortunately, no allergen test is perfect and false positives do occur. Doctors may suggest an oral food challenge (OFC) to verify results. This involves consuming small amounts of possible allergens in the safety of the doctor's office, slowly increasing in quantity, and watching for any allergic reaction. Again, this provides a first-hand experience of your food-related symptoms.
Key Takeaway:
When it comes to chronic reactions and food sensitivities, it is important to dig deeper to understand the root causes. Typically, these symptoms highlight underlying issues. While food sensitivity testing seems like an easy fix, we encourage a more thorough examination and elimination method.
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