The Growing Challenge of Food Sensitivities
More and more people are discovering that certain foods, even healthy ones, are causing them harm. A food sensitivity is a negative reaction by the body to a food that is generally considered nutritious, like a specific fruit or vegetable. While the food itself has wonderful properties, it causes health problems for the person sensitive to it. This bio-individuality makes diagnosing sensitivities notoriously difficult.
Our unique genetic makeup also plays a crucial role, influencing how our bodies respond to different foods—a field known as epigenetics. As expert Dr. Ben Lynch notes, understanding how to support your specific genes through diet and lifestyle can be the key to unlocking optimal health. However, identifying the precise triggers remains a significant hurdle.
Why IgG Blood Tests for Food Sensitivity Are Unreliable
You have likely heard of blood tests that claim to diagnose food sensitivities by measuring IgG antibodies. The theory is that these antibodies are produced against specific foods, indicating a sensitivity. Unfortunately, the reality is more complex.
The primary problem with these tests is their questionable validity. Today, we don’t even know for certain if high levels of IgG antibodies truly point to a food sensitivity. Furthermore, sensitivities likely develop through multiple biological mechanisms, many of which are not measured by an IgG test at all. This leads to two common and frustrating scenarios:
- A person with clear symptoms of a food sensitivity receives a negative test result.
- A person receives a test showing many sensitivities, but avoiding those foods brings no symptom relief.
Given that these blood tests are quite expensive and often inaccurate, I do not recommend them. However, if for any reason you decide to proceed with one, choose a panel that tests for fewer than 80-100 foods, as the technical accuracy of the test can decrease drastically with larger panels.
How Classical Food Allergies Are Different
It’s important to distinguish food sensitivities from classical food allergies. Unlike sensitivities, true allergies are well-defined medical conditions. They can be identified through skin-prick tests available through your doctor. These allergies typically involve a severe and immediate immune response and are often discovered in childhood.
If an adult suspects a true allergy, getting tested is crucial. Any food that tests positive for an allergy must be completely removed from the diet.
The Diagnostic Gap: When Allergy Tests Are Negative
Here is a critical point: even if your allergy test comes back negative, it doesn’t mean you don’t have a problem with certain foods. A negative result simply rules out a classical allergy. You may still have food sensitivities that are causing your symptoms.
So, if common lab tests are unreliable for sensitivities and allergy tests don’t detect them, how can we find answers? In Part 2 of this series, we will explore effective clinical methods that look beyond simple antibody counts to provide a more accurate diagnosis.
