Why I don't use IgG Sensitivity Testing

IgG testing is the most popularly marketed food sensitivity testing. And it also is a scam... Part of my job is to prevent you from spending money on things that won't provide you a return on your health.
The problem with IgG testing is that it assumes all IgG is pro-inflammatory. However, research clearly points out that some IgG is anti-inflammatory and protective against sensitivity. In fact the more it builds up the more protective it is. This is true for IgG4, and other types of IgG, which are still being discovered.

The pro-inflammatory activity also depends on which immune cells the IgG is binding to. IgG's job is to show the immune system the item it has found, and then the immune system can launch an attack, or a protective defence.

IgA testing has been found to be somewhat more accurate than IgG, however, we face the same problem, that many labs are not able to identify which immune cells IgA is binding to.

Unless a lab's IgG tests can differentiate between pro and anti-inflammatory IgG I won't be using it with my clients.

The argument for using testing?

Food sensitivities are mediated by IgM, IgG food antibodies and other immune cells, which usually result in a delayed symptom response to a food. Real allergies, mediated by IgE antibodies, usually result in immediate-hypersensitivity to a substance. It is generally easier for patients and clinicians to identify a food that causes an immediate response. A delayed-response to food may be more challenging to determine via elimination.

In particular food sensitivity testing would be useful for those who also have an autoimmune disease or who have neurological symptoms.  If you feel like you don't tolerate any food and you can't tell what you do or don't tolerate. 

When not to use food sensitivity tests

If financial resources are limited do not start with food sensitivity testing. Focus on stool testing, correcting the gut and microbiome and the gut barrier, which often does help reduce food sensitivities. If symptoms persist despite consistent work with the gut, then use food sensitivity testing, but be careful about the type of testing you use.

Tests that cover food AND chemical sensitivities  (my first choice if accessible)

The ALCAT Test

This testing measures the entirety of your leukocyte response to food and chemical sensitivities, which includes them binding to IgM, IgG and IgG4, among others. You can mix and match your own test choosing to test sensitivity items such as:

mold

preservatives

expanded preservatives and additives

commonly used superfoods and herbs

male herbs

female herbs

antibiotics and antiinflammatories

and from 50 to 250 foods.

This test is available in Canada

KBMO FIT Test

KBMO measures IgG antibody specifically in immune complexes with complement (which dramatically helps eliminate false positives but may have false negatives).  This one is notably less expensive but still a sizable investment.  For US based patients who can afford to do so, these are excellent choices.  (This company drop ships)

– FIT 22 $150 USD
– FIT 132 $350 USD (fingerstick or blood draw)
– FIT 176 $450 USD

This test is available in the USA