What do they actually test for?
….Hint: we don’t mean ingredients!

Not all IgG blood tests are the same and, sometimes, it can be extremely difficult to work out who tests for what. Now this is where it gets science-y but you don’t need to be a scientific whizz to understand all about IgG and how it plays an important part in a test’s credibility.

A reliable method for food intolerance testing is through IgG analysis, which is a fancy name for testing the reactions to the proteins in foods. IgG stands for Immunoglobulin G.

There are four subtypes of IgG. In normal human blood, IgG1 is the most prevalent, making up around 60-70% of your total IgG, followed by IgG2 (20-30%), IgG3 (5-8%). IgG4 only makes up 1-4% of the IgG antibodies present.

IgG1, 2 and 3 are all capable of causing inflammation which could contribute to food intolerance symptoms. IgG4 antibodies, however, are only present in low levels and its presence is not as relevant to inflammatory reactions.

What does this mean for you? The truth is – a lot more than you think. The value of choosing a testing provider which only tests IgG4 and using those results for your elimination diet is actually very limited and there’s little evidence that this is helpful.

There are a few food intolerance providers out there which only test for IgG4. Check them out below:

Which food intolerance companies test the full range of IgG levels?

(Accurate as of October 2018)

Food for thought: Would you pay for a whole pizza when you’re only able to have a slice?

The answer is: we hope not! It’s important you get the most bang for your buck, and a food sensitivity test which only tests 1-4% of your IgG profile is not a useful food intolerance test. It’s like paying to view a famous painting in a gallery. Would you pay to see the corner of a painting?

If you’re going to buy a test, make sure you don’t get left in the cold by only seeing the tip of the iceberg.