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  • Writer's pictureAshley Sauvé Health

Why IgG Food Sensitivity Testing May Not Be Helpful

If you’ve narrowed yourself down to 10 safe foods that don’t create any bloating or gas after eating them... you’re likely familiar with the topic of this article: food sensitivities.

Food intolerances and sensitivities are prevalent, and I see it all the time where clients are one by one, removing foods from their diet because they’re causing them digestive discomfort.

The thing is, avoiding the foods isn’t the solution. While avoiding foods may help in the short-term with symptom relief, they aren’t addressing the underlying reason why you might be experiencing food sensitivities in the first place.

This article is going to dive deeper into food sensitivities, IgG Food Sensitivity testing, why that testing may not be helpful and what I recommend instead.

Food Sensitivities

Food sensitivities on the other hand can be difficult to pinpoint. They involve IgG (which we’re going to be covering here), or IgM antibodies and can take up to three days to cause a reaction after eating the food. Reactions related to food sensitivities often include symptoms that are not obviously related to digestion, like headaches, joint pain, and skin issues, which can be related to how much was consumed (a little may be fine but a lot may cause issues). An example of this would be a nightshade sensitivity that causes eczema to flare up within 1-3 days of consuming foods like tomatoes, eggplant, or peppers.

What is IgG Testing?

IgG (immunoglobulin G) is an antibody that our immune system produces and secretes, to neutralize and protect us from threats or foreign invaders in the body.

For our purposes here, these “threats” or “foreign invaders” are antigens in our food.

Antigens are substances that initiate the immune system in the body to make antibodies. With this test, we’re measuring how the body’s immune system is responding to these substances from the food we’re consuming.

IgG testing can be done using either serum (blood) or DBS (dried blood spot) testing methods, and is used to help identify IgG antibodies.

Depending on the test, we can test for IgG antibodies against hundreds of foods, to see how a person may or may not be responding to them.

Generally the idea with these tests are to identify food sensitivities, and have a person avoid them with the intention of taking stress off the body.

Why I Don’t Love IgG Testing

I am not a fan of IgG Food Sensitivity tests because they can give a lot of false positives and are not necessarily correlated with the symptoms of a food sensitivity. Especially digestive symptoms, which may have nothing to do with IgG antibodies at all.

For IgG antibodies to show up through IgG testing, a person needs to be actively eating the foods that they’re testing for.

What tends to happen, is that someone who is struggling with their gut health will have this test run, and the results will come back with all of the foods they’ve been recently eating, lit up like a Christmas tree.

Does it really make sense that a person would be sensitive to all these foods? Is it realistic to ask clients in this case to avoid all of these foods?

Food sensitivities can develop when the gut lining becomes permeable (aka "leaky gut"). In this situation, food antigens can make their way through the intestinal lining, and into circulation, where our immune system is put on high alert, creating antibodies to fight these “foreign invaders.”

The thing is, these antigens are meant to stay within the gut and not make their way through the intestinal lining, and into the bloodstream.

This is where IgG food sensitivity testing can be a little unreliable.

Instead, it may be more helpful to implement an anti-inflammatory diet, and focus on good gut health and restoring the integrity of the intestinal lining.

Healing the gut lining will reduce the number of antigens making their way into our bloodstream, causing this immune response, lessening food sensitivities.

Alternatives to IgG Testing (GI MAP)

Food sensitivities aren’t a root cause. When it comes to gut healing and digestive health, it’s important to look beyond symptoms like food sensitivities to address why someone would be experiencing them.

That’s why I love using the GI-MAP stool test in practice with my clients. The GI-MAP gives us a much more comprehensive picture as to what’s going on in the gut, and investigates what could be contributing to intestinal permeability and food sensitivities that you may be experiencing so that they can be addressed using a root-cause approach (versus simply avoiding all of your “sensitive” foods for the foreseeable future.

I wrote all about why I love the test, and what it can tell us here.

I believe that it’s a much better investment of my clients money, and can provide us with more information to work with to develop a sustainable, gut-healing plan to address food sensitivities and any associated symptoms.

To learn more about how I help my clients navigate their food sensitivities, and use the GI-MAP stool test to uncover underlying imbalances, check out my program Gut Rehab Intensive.

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