Food Allergies In Kids– Are IgG Food Sensitivity Tests Useful?

Is there any good reason to take certain foods out of a child's diet if they don't cause a full-blown allergy?

Could food sensitivity be causing a child's aggression, or tantrums, or ADHD, or eczema?

Is there value in testing for food sensitivity?

Short answer... food is one source of stress I explore with the families I work with but there's more to your child's story and food sensitivity testing isn't always a good idea.

This article outlines how I suggest you think about food sensitivities, especially as they relate to mood and behavior in kids, and my current thoughts about testing.

What Is A Food Sensitivity?

Food sensitivity happens when the immune or nervous system mounts a hyper-response to certain food and consider it a threat. There is no IgE antibody release (which there is in a true allergy), but there is still inflammation and a symptom. 

So that's the first thing piece to understand - food sensitivity is not an allergy, but it is a situation in which food triggers inflammation and symptoms (kinds like an allergy).

For some kids, food sensitivity is a big contributor to their skin, bowel, and behavior issues and figuring this out yields great results. I think of a young client, Jonah, who went from 5 meltdowns a week to 1 and completely stopped having panic attacks when we took out gluten, cashews, and cucumbers.

Finding food reactions brought about a remarkable change in Jonah's experience and the family dynamic!

But I want you to clearly understand what food sensitivities tell you and don't tell you, and the controversy around food sensitivity testing so you don't waste your money.

Three Tricky Things About Food Sensitivity

Unlike a full-blown allergy (which is fairly straightforward for your doctor to diagnose), food sensitivity can be tricky to tease out for three reasons:

1. Symptoms of a food sensitivity can be just about anything. Fatigue, hyperactivity, skin rashes, tummy pain... pretty much anything.
2. Reactions can be delayed. If you eat something today, you might feel the symptoms in 2-3 days.
3. A food sensitivity might not actually involve the immune system. It might be more of a nervous system irritation, as in the case of phenols or glutamate; it may be more of an enzyme issue, as in the case of lactose intolerance. 

Tricky. And why people often turn to food sensitivity tests for answers (we'll get to the pros and cons of that).

Food Sensitivity Is A Symptom, Not A Diagnosis. A Recent Conversation....

Before you go down the food sensitivity rabbit hole I want you to know a few things...

A food sensitivity is not a diagnosis or a condition. It's not an endpoint.

I'll explain by recounting a recent interaction I had with a mom.

A mom of three approached me, interested in running a food sensitivity test for her son who was experiencing ADHD-like behavior, dry patchy eczema-like skin, and interrupted sleep. She wanted to know if food might be the trigger.

The food sensitivity test I like (called the Food Zoomer) runs about $450 and requires a blood draw or finger prick. So I'm always careful before recommending parents spend that kind of money.

The test looks at IgG and IgA reactions to proteins and peptides (sections of proteins). I like this particular test because it "zooms in" on peptides, making it much more accurate than the typical food reaction test that only looks at proteins.

The validity of using IgG as a marker is hotly debated because IgG antibodies are "memory" antibodies; they can be in the blood simply because the immune system has seen a food for a second time. So if your child eats a lot of pineapple they may have high IgG antibodies to pineapple, but that doesn't mean there's a problem with pineapple.

On the other hand, a specialized test like the Food Zoomer can be a helpful screening tool to see if any foods are eliciting an extreme response. An extreme IgG response to pineapple, especially if there is also an IgA response, would be a red flag indicating that it could be a source of inflammation and immune activation and it's worth your effort to take it out for a while to see what happens. Furthermore, if there are extreme elevations to multiple foods it tells you there is probably an issue with the microbiome and digestion (more on that later).

Bottom Line: a food sensitivity test can point us towards a potential source of irritation and stress but it doesn't mean we have necessarily found one. A test looking at peptides is a much more accurate way to decide if it's worth taking a food out than the ones that just look at whole proteins. Either way, we use the information to construct a careful elimination-provocation diet to determine if these foods are, in fact, contributing to symptoms and we use it as a screening tool to gauge the health of the microbiome and digestion. Keep in mind, that all food sensitivity tests assesses only an immune type of reaction. None of them are looking at enzymes or nervous system reactions (point number 3 above)

To this mom worried about her son, I asked these questions:

1. How urgently do you need to resolve the behavior of concern? Do you have time to tinker or are you in crisis?
2. What do you think he's reacting to? What have you observed?
3. How traumatic is it for your son to go through a blood draw or finger prick?
4. How comfortable are you in the kitchen? Do you cook? Are you open to experimenting with food?

She told me she had observed that when her son ate cheese and tomatoes he got lethargic and irritable. When she took them out he felt better.

She was ok with taking them out and willing to try some new recipe ideas to see how it went.

She admitted that his fear of needles meant getting blood from him was likely to be very hard and that money was a concern.

Here's what I suggested instead of a food sensitivity test

I gave this mom a copy of my book, which outlines how to improve digestive capacity while also nourishing the body, and suggested she work on those strategies first. (if you get a copy of the book be sure to also get the bonuses and updates here)

I suggested that at the same time, she keep out the cheese and tomatoes and any other food that was clearly causing noticeable symptoms.

Then, if her son was still having symptoms and not tolerating cheese and tomatoes (or anything else) she could consider a food sensitivity test as a way to dig deeper, but I suggested she combine it with an assessment of the microbiome to better understand where digestive capacity needed support. 

Bottom Line:  In most cases, the problem is not the food itself. The problem is how the body is receiving the food. At this point in my work, I never suggest a parent invest in a food sensitivity test without also running a gut microbiome test. If they can only do one of the two, I suggest they go with the gut microbiome test because that is where the work is. 

So Are Food Sensitivity Tests Helpful?

They can be. But they are not always.

There is no doubt in my mind that irritation caused by food is worth exploring if your child is struggling with their health in any way. Food is one of 5 sources of stress I consider. (Read this post to learn about the others.)

If left undetected food sensitivities can cause myriad symptoms that involve the skin, the bowel, the brain, behavior, hormones…. just about every body system can be affected.

But remember... the problem is not the food itself, it's the inflammation triggered by the food. And that's usually because of poor digestion.

The IgG test is not a diagnosis of an allergy; it is just a screening tool to help identify potential irritation. It's important to use that information to construct an elimination diet to see if those foods are actually problematic.

Since restricting a child's diet can be difficult and can open the door to nutritional deficiencies, we have to be careful with kids.

Why Are Food Sensitivities So Common & What Should We Do? 

It is estimated that 1 in 3 children suffers from a food sensitivity and the issue seems to be on the rise (source). 

They're becoming so common because our digestive and immune systems are under increased pressure.

Here are a few possible reasons for an increase in food sensitivity:

• Increased exposure to environmental toxins is putting extra burden on our immune systems and making it more likely to over-respond,
• Nutritional deficiencies lead to slower digestion and poor digestive ecology,
• Things like antibiotics, sugar, stress, and chemicals weaken the digestive and immune systems,
• Genetically modified food is interfering with digestive and immune response,
• Increased rate of cesarean births but kids at risk of developing a hyperimmune response 

All of this can contribute to food sensitivities so it’s not that surprising that we are seeing more kids becoming sensitive to more foods. 

The real key to managing food sensitivities is to address the things that are eroding resilience. When we do, we often see sensitivities resolve on their own without ever having to restrict foods or test.

If you do use an IgG food sensitivity test, use it as a guide to construct a temporary elimination diet to relieve immediate pressure while you work on restoring gut ecology.   

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Related posts:

jesssherman.com/blog/child-mental-health

jesssherman.com/blog/3-Things-Every-Parent-Needs-To-Know-About-The-Gut-Brain-Connection

jesssherman.com/blog/can-changing-a-child-s-diet-help-adhd

jesssherman.com/blog/does-diet-improve-autism

 jesssherman.com/blog/food-allergy-in-children

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References:

Are Attention Deficit Hyperactivity Disorder and Chronic Fatigue Syndrome Allergy Related? What is Fibromyalgia?

Inflammatory symptoms, immune system and food intolerance: One cause – many symptoms.

https://epidemicanswers.org/reference-library/allergies-and-sensitivities/allergies-sensitivities-101/

https://pediatrics.aappublications.org/content/135/1/e92.short