The IgG blood tests are not valid. This explains why the IgG antibodies cannot determine if someone is intolerant to food but here's the basics.
Food intolerance blood tests have no place in the pharmacy
There is no published evidence cited on the Rexall site or the Hemocode site that documents how this test have been validated. Importantly, food intolerances are non-allergic by definition. So why test immunoglobulin G (IgG)? IgG molecules mediate interactions of cells with different cellular and humoral mechanisms. IgG antibodies signify exposure to products—not allergy. IgG may actually be a marker for food tolerance, not intolerance, some research suggests: |
Children with eczema and egg or milk allergies with higher levels of IgG to milk/egg were more likely to be tolerant of these foods at a later age.
Resolution of cow’s milk allergy is associated with increasing IgG
A study found increasing IgG in patients who underwent oral immunotherapy for milk or peanut allergy
Given the lack of correlation between the presence of IgG and physical manifestations of illness, IgG testing is considered unproven as a diagnostic agent as the results lack clinical utility as a tool for dietary modification or food elimination. So I consulted the medical literature for consensus clinical opinion on IgG blood tests, for tests like Hemocode. I summarized the literature in a lengthy post on the diagnosis of food intolerance and the use of IgG testing over at Science-Based Medicine.