I thought I’d finally write a follow-up to one of my most popular articles, Food Sensitivity Testing: What You Need To Know.

As I stated in that article, I’m actually not a huge fan of IgG food intolerance testing. I do use it occasionally with my patients, but it’s never, ever one of the first things I do. This is partially because I have noticed that these tests tend to be very confusing and frustrating for the patient. Also, they tend to produce a high amount of false positives and false negatives, which is all the more frustrating for both doctor and patient.

To show why they can be confusing, I have provided an example of a test run through Genova Diagnostics below. Take a look at the dairy section- notice anything? They break diary down into seemingly random categories (some labs break dairy up even more). How can someone have a sensitivity to cheddar cheese but not cottage cheese? Or yogurt? Isn’t it more likely that a patient with 1 or 2 red flags in this section has a casein or a whey sensitivity and should not eat any dairy?

Part of the reason for the high number of false negatives and false positives in this type of testing is because results can be highly dependent on the integrity of the patients gut. If you have a leaky gutdon’t make enough stomach acid, or have small intestinal bacterial overgrowth (SIBO) all of those things will likely skew your results. I have seen patients come in with 20 or more “positives” on this type of testing, only to find out later that once we cleaned up their gut and healed their leaky gut, many went away.

This is why this type of testing is always a last-ditch effort in my office. I will only run this type of test once we have accounted for all the myriad of things that can skew the results. If we do all we can possibly do to clean up the gut and the patient still has symptoms, then and only then will I consider running this type of test.

In health,


If you or somebody you know is interested in working with a functional medicine doctor please call my office at (919) 238-4094 and see if we are the right fit for you. ​Infinity Holistic Healthcare is located in Chapel Hill, North Carolina, part of the Raleigh-Durham “triangle” area.

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