A few months back I wrote about a food allergy panel that our doctor ordered to check my son for food allergies. I really should have asked a lot more questions before agreeing to spent $300 for this test. It’s expensive and poking your sensory kids finger for blood is a horrible experience for all.
My son’s results indicated he had elevated IgG results to several foods. We were told he needed to be off these foods for a period of time to help his body’s immune response calm down.
Four months later with no improvement I compared notes with another parent that also reported no change in symptoms/behavior when removing foods based on this same test. This parent ran a follow-up test nearly 6 months into the diet. The results were very puzzling.
This made me wonder what is an IgG antibody anyway? It turns out that it’s a “memory” antibody and it signals past exposure to a food antigen. It does not indicate an allergy to it. What? Wait….past exposure not allergy?
My son was eating the very foods before testing for months that were elevated on the test.
My friend’s child’s follow-up testing showed that the elevated antibodies to those original foods went down which is what you’d expect if you weren’t eating them for 6 months. What we did not expect was there were now elevated antibodies to the new foods the child has been eating to replace the ones he couldn’t have. So now instead of having elevated IgG to milk he has it to soy because his cow milk was replaced with soy milk.
So we both looked at each and thought…so does it matter what he eats or are these antibodies just going to go up and down depending on what you eat?
So I decided to investigate the validity of this kind of testing because both my kids took it and were put on elimination diets which did showed in changes at all. When the foods were slowly added back in there was no response either. That made me wonder how valid is this test?
I had a hard time finding valid scientific research that demonstrates that elevated IgG to foods actually indicates a food intolerance when there are no food allergy symptoms to begin with.
Some of the information I found:
- IgG food intolerance tests: what does the science say?
- CSACI statement on IgG testing
- IgG food allergy testing: What do they really tell us?
I think in our case the IgG testing may not have been helpful. After having done an allergy elimination diet on myself for nearly a year I find the best indicator of a food intolerance are symptoms or any improvement when removing the food.