The Mediator Release Test (MRT) is a specialized blood test used to identify specific foods and food chemicals contributing to chronic inflammatory symptoms. Unlike tests for immediate food allergies, the MRT focuses on identifying non-IgE-mediated hypersensitivity reactions, which are often delayed and dose-dependent. This testing provides personalized data that guides a structured, anti-inflammatory eating plan for individuals suffering from persistent, unexplained symptoms.
Defining the Mediator Release Test
The Mediator Release Test is a functional measure of inflammatory responses triggered by exposure to various foods and additives. It is classified as an “end-point” test because it measures the final event in a chain of immune reactions: the release of pro-inflammatory chemicals. The test uses a sample of whole blood, containing circulating white blood cells, and exposes them directly to a panel of food and chemical antigens.
The MRT differs conceptually from traditional food allergy testing, which measures IgE antibodies responsible for immediate, severe allergic reactions. It is also distinct from standard IgG food sensitivity tests, which measure only one type of antibody. The test captures adverse reactions from various immune pathways—including both antibody-mediated and cell-mediated responses—that culminate in inflammation.
The Immunological Basis of the MRT
The core principle of the MRT centers on the activity of white blood cells, or leukocytes, in response to a suspected trigger food. When a food or food chemical acts as a sensitivity trigger, various types of immune cells, such as neutrophils, monocytes, and lymphocytes, become activated. This activation causes the cells to release inflammatory molecules known as mediators into the surrounding fluid.
These mediators include compounds like histamine, leukotrienes, prostaglandins, and cytokines, which generate pain, inflammation, and other physical symptoms. The MRT detects this release indirectly by measuring the volumetric change in the white blood cells after incubation with the test substance. As the cells release their contents, they experience a measurable change in their liquid-to-solid ratio.
The test quantifies this physical change using a patented impedance-based measurement system. A significant volumetric change indicates a strong inflammatory response, suggesting the tested substance is a trigger for the individual. Measuring this final, common step of mediator release provides a comprehensive assessment of the body’s overall inflammatory reaction.
Clinical Conditions Addressed by MRT
The MRT is most commonly utilized for individuals experiencing chronic inflammatory conditions that have not responded well to conventional treatments. This includes functional gastrointestinal disorders such as Irritable Bowel Syndrome (IBS), characterized by persistent bloating, abdominal pain, and altered bowel habits. Identifying food triggers in these cases helps reduce the chronic low-grade inflammation that maintains the condition.
The test is also frequently applied to help manage chronic migraines and other headache disorders, where food sensitivities can act as a trigger, often with a delayed onset of symptoms. Other conditions where the MRT may be used include fibromyalgia, which involves widespread musculoskeletal pain, and chronic fatigue syndrome. The rationale is to pinpoint the dietary components sustaining systemic inflammation, providing a targeted approach to reduce symptom severity.
Translating MRT Results into Personalized Nutrition
The practical value of the MRT lies in its ability to translate complex inflammatory data into a highly structured, personalized eating strategy. Test results classify each food and food chemical into three categories based on the magnitude of the measured volumetric change in the white blood cells. These categories are typically color-coded: green for non-reactive, yellow for moderately reactive, and red for highly reactive.
The results serve as the foundation for a structured elimination and reintroduction diet protocol, often referred to as the LEAP program. This protocol begins by restricting the diet to only the lowest-reactive, “green” category foods to reduce baseline inflammation. This initial phase is designed to achieve significant symptom reduction, typically within two weeks.
Following the initial strict elimination, foods are systematically and gradually reintroduced in phases, starting with the least reactive “yellow” items. This controlled reintroduction phase allows the individual and their practitioner, often a Certified LEAP Therapist, to monitor for any return of symptoms. The ultimate goal is to expand the diet as much as possible while maintaining a low inflammatory load, creating a sustainable, individualized nutrition plan that promotes long-term wellness.
Current Scientific View and Test Limitations
The Mediator Release Test is primarily used within the field of complementary and functional medicine, and its place in conventional medical practice remains a subject of ongoing debate. Proponents cite studies that show a high degree of accuracy, with reported sensitivity and specificity rates often exceeding 90 percent. They also emphasize its clinical utility in providing an actionable path for patients with complex, chronic inflammatory symptoms.
However, major medical organizations, such as the American Academy of Allergy, Asthma & Immunology, do not currently endorse the MRT for diagnosing food sensitivities or allergies. These organizations note a lack of large-scale, independent, peer-reviewed clinical trials to fully validate the test’s efficacy compared to established diagnostic methods. The test is specifically not a tool for diagnosing true IgE-mediated food allergies, which require different testing.
Patients should also consider that the test is not typically covered by standard health insurance and requires professional interpretation by a Registered Dietitian or physician to effectively implement the resulting elimination protocol. The most significant limitation is the risk of unnecessary dietary restriction if the results are not managed correctly, highlighting the importance of pairing the test with professional guidance.