Do At-Home Food Sensitivity Tests Work? Try These Solutions Instead

It can be a real pain in the gut to try and figure out what kinds of foods don’t sit well with your body. When you’re dealing with recurrent stomach pain, bloating or diarrhea, how do you even begin to pinpoint the cause of your symptoms when you’re always eating a variety of foods and spices?

In the hopes of finding a quick solution, people are turning to at-home food sensitivity tests to determine what they should cut out of their meal plans. But allergy and clinical immunology specialist Ahila Subramanian, MD, MPH, emphasizes that these tests aren’t at all accurate. Instead, you should avoid them whenever you’re trying to self-diagnose the causes of your symptoms.

How are at-home food sensitivity tests done?

At-home food sensitivity tests claim to measure your body’s immune response to a broad variety of foods by testing the levels of immunoglobulin G (IgG) antibodies in your blood.

For these at-home tests to work, you need to submit a small blood sample. Once you send in your sample to a laboratory, the lab screens it for up to 200 or more foods, like cow’s milk, eggs, oats, seafood and fruits. This screening determines which of these foods cause the highest levels of IgG in your blood. Upon receiving your results, these companies then often suggest eliminating the foods with the highest levels of IgG to see if the absence of those foods has any impact on your symptoms.

“These tests come back with really large reports that have warnings for high IgG levels, but these tests cause more harm than benefit,” warns Dr. Subramanian.

Are food sensitivity tests accurate?

There aren’t any scientific studies or clinical trials with evidence that these at-home food sensitivity tests work. And they’re often not covered by insurance. Further, multiple organizations like the American Academy of Allergy, Asthma & Immunology and the Association for Diagnostics & Laboratory Medicine don’t recommend using these at-home IgG tests to diagnose food sensitivities or intolerances.

“These tests don’t truly tell us if someone is intolerant to these foods,” clarifies Dr. Subramanian.

IgG antibodies are the most common antibodies in our immune system that help protect us against viral and bacterial infections. They also work like security guards or note-takers. They play a crucial role in marking which foods (or allergens) are safe, thus maintaining our body’s tolerance to these objects.

So, if you eat apples regularly, you’ll likely have higher levels of IgG because they’re telling your body the apples are safe and not worthy of an attack.

You can think about it another way by looking at a child’s food allergy to peanuts. If a child has a peanut allergy, they tend to have higher levels of IgE antibodies whenever they come into contact with peanuts. That’s because IgE antibodies cause the release of histamine that’s responsible for their allergic reactions.

“When we follow them as they get older to see if they’re outgrowing their peanut allergy, their IgE level usually goes down but their IgG level will go up,” explains Dr. Subramanian. “Kids that have outgrown their peanut allergy usually have a high IgG and we like to see that because it shows us they’ve built a tolerance for peanuts.”

So, if you have a high level of IgG, it doesn’t really mean you have a food intolerance. And having a low level of IgG has no clinical meaning because you could have lower IgG levels if you’ve been eating less of those foods in the last few weeks or you’ve been dealing with an infection that utilized those IgG antibodies for other areas of protection.

Given how IgG works in general, these at-home food sensitivity tests are likely to cause more confusion than offer any real solutions.

“You’re very likely to get a high number of false positives because you are eating foods that give you high IgG levels,” notes Dr. Subramanian. “There are no studies, no good head-to-head clinical trials, that have shown these at-home tests show anything other than these people have tolerance antibodies to these foods.”

Other causes for your symptoms

Food intolerances and sensitivities are often tied to gastrointestinal symptoms like bloating, stomach pain, diarrhea or indigestion. But these symptoms can also be a sign of a more serious underlying medical condition like:

• Crohn’s disease
• Ulcerative colitis
• Small intestinal bacterial overgrowth syndrome (SIBO)

Even everyday events like stress or lack of sleep could have an impact on the way your body reacts to the products you eat and drink.

“It’s really commonplace now to blame foods for everything,” notes Dr. Subramanian. “It’s important to talk about your symptoms with your healthcare provider to help distinguish between the type of reactions you’re having and to make sure you’re being appropriately evaluated for other potential conditions.”

What to do if you think you have a food sensitivity or intolerance

If you think you’re dealing with a food sensitivity or intolerance, keeping track of your symptoms and communicating with your healthcare provider is key.

“Generally, the best tool we have in identifying triggers with intolerances and sensitivities is a food symptom journal,” states Dr. Subramanian. “Unfortunately, because of the way intolerances work and because we have so many different foods and spices available to us, a food journal is going to be the most effective way of identifying triggers.”

Try keeping a food journal for a month, writing down which foods and drinks you have throughout the day and keeping tabs on which symptoms you experience (and at what times).

“Even after a few weeks, if your symptoms are episodic, we can start to pick out patterns,” she adds.

The challenge with food intolerances vs. food allergies is that you don’t always experience symptoms right away. Often, your symptoms can be systemic, meaning they could affect your whole body in different ways, or they can creep up hours after eating.

“The severity of intolerances can really vary from person to person,” she continues. “It could also be a hidden problem. If there was dairy in a dressing, for example, it could irritate that person’s gut without them knowing it was caused by dairy.”

When it comes to conditions like lactose intolerance, we know it takes some trial and error to figure out which solutions might work best for you. That makes scheduling an appointment even more important, particularly if you’re considering an elimination diet.

The bottom line?

“Trying to avoid multiple different foods can cause nutritional deficiency, so you don’t want to do an elimination diet on your own,” stresses Dr. Subramanian.

“Elimination diets are most successful when you’re working with a dietitian because they can work with you to figure out how to replace the foods you’re taking out of your diet while maintaining a nutritionally balanced meal plan.”