What is the relationship between IgG (Immunoglobulin G) ELISA (Enzyme-Linked Immunosorbent Assay) and food sensitivities?

From the Guidelines

IgG ELISA tests are not recommended for diagnosing food sensitivities due to their poor specificity and lack of correlation with clinical symptoms. The presence of IgG antibodies to specific foods does not necessarily indicate a food sensitivity or intolerance, as these antibodies can be present in healthy individuals without causing symptoms 1.

Limitations of IgG ELISA Tests

• IgG antibodies to foods can be present in healthy individuals without causing symptoms
• The tests have not been scientifically validated for diagnosing food intolerances
• Poor specificity and applicability of IgG antibody testing

Recommended Approach for Diagnosing Food Sensitivities

• Elimination diet followed by controlled food challenges is the gold standard for identifying food sensitivities
• This involves:
  1. Eliminating suspected trigger foods for 2-4 weeks
  2. Gradually reintroducing foods one at a time
  3. Monitoring symptoms for reactions
• Work with a registered dietitian or allergist to guide you through this process and ensure nutritional needs are met during the elimination phase 1

Importance of Clinical Correlation

• Positive test results only signify sensitization and require clinical correlation and confirmation to establish presence of allergic disease and the exact type of allergic response
• Focusing on symptoms and their relationship to specific foods through a structured elimination diet provides more actionable information for managing food sensitivities in daily life 1

From the Research

Relationship between IgG ELISA and Food Sensitivities

• The relationship between IgG ELISA and food sensitivities is supported by some studies, which suggest that IgG-based testing can be useful in guiding elimination diets and identifying food sensitivities 2, 3.
• A study published in 2004 found that dietary elimination based on the presence of IgG antibodies to food can be effective in reducing symptoms of irritable bowel syndrome (IBS) 3.
• Another study published in 2010 noted that IgG-based testing showed promise and had clinically meaningful results, making it a useful guide for elimination diets 2.
• However, other studies have highlighted the limitations and complexities of diagnosing food allergies and sensitivities, and the need for further research to standardize diagnostic approaches and treatment strategies 4, 5, 6.

Diagnostic Approaches

• The diagnosis of food allergies and sensitivities is complex and often involves a combination of clinical history, skin prick tests, and other diagnostic tests 4, 5, 6.
• IgG ELISA is one of the tests used to diagnose food sensitivities, but its validity and clinical application are still being researched and debated 2, 3.
• The gold standard for diagnosing food allergies is still the double-blind placebo-controlled challenge, but this approach is not always feasible or practical 4, 5.

Clinical Applications

• IgG ELISA may be useful in identifying food sensitivities and guiding elimination diets, particularly in patients with IBS or other gastrointestinal disorders 3.
• However, more research is needed to fully understand the relationship between IgG ELISA and food sensitivities, and to standardize diagnostic approaches and treatment strategies 2, 4, 5, 6.