Do Food Sensitivity Tests Work? What You Need to Know

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Many people have food sensitivities, which are immune responses to specific foods that can worsen or trigger a wide range of symptoms.

Figuring out if you are sensitive to a particular food or groups of foods and taking steps to adjust your diet can improve your health and your quality of life.

But identifying exactly what food or foods you may be sensitive to is a complicated process, as food sensitivities are still not well understood.

And, so far, no at-home test can accurately and definitively diagnose food sensitivities.

This article will explain what we know about food sensitivities and why figuring them out is so tricky. It will also explore what else may be going on if you think your symptoms might be related to a specific food.

In general, food sensitivities occur when your immune system reacts to a specific food. It’s believed that they result from an immune reaction driven by antibodies such as immunoglobulin G (IgG), immunoglobulin M (IgM), and immunoglobulin A (IgA), along with other cell-mediated reactions in the body.

And while they are not life threatening, food sensitivities can cause unpleasant symptoms.

For example, research has linked non-celiac gluten sensitivity — a food sensitivity triggered by a type of protein found in wheat, barley, and rye — to symptoms such as bloating, stomach pain, brain fog, depression, and skin inflammation.

Though more studies on food sensitivities are necessary, research from 2019 suggests that some people may be sensitive to elements of certain foods, including lectins, a type of protein found in many plant foods like legumes, or to food groups, such as nightshade vegetables.

At-home food sensitivity tests check how your immune system responds to different types of food.

A blood sample is collected through a finger prick with a small lancet, which is then mailed to a lab to undergo testing.

The exact process may vary depending on the specific testing kit you purchase, and some brands might also require hair or saliva samples, or a breath test.

Results are usually provided online within a few days or weeks after your sample is received.

In short: No. There’s limited evidence to support using at-home food sensitivity tests.

Many of these tests measure your body’s immune response to a variety of foods by testing the levels of certain antibodies in your blood, such as IgG and IgG4, after you’re exposed to various food antigens.

Yet some research suggests that the presence of these antibodies may not be an accurate or reliable marker of food sensitivity, especially because many other antibodies and cell-mediated reactions may also be involved in food sensitivities.

What’s more, many of the studies that companies cite to support using these tests are outdated or have been published in non-reputable journals.

Some tests claim to help you understand how your body may respond to certain foods based on factors like your genetic background. However, the research surrounding genetic testing and food allergies and sensitivities is also quite limited.

Multiple organizations, including the Canadian Society of Allergy and Clinical Immunology and the American Academy of Allergy, Asthma & Immunology (AAAAI), have advised against using these tests to diagnose food sensitivities.

Overall, more reliable testing methods are necessary before at-home testing kits can be recommended to diagnose food sensitivities.

Other concerns surrounding at-home food sensitivity tests

Because at-home food sensitivity tests may or may not be accurate, they are associated with several risks, including:

• unnecessary elimination of foods from your diet
• inadequate intake of important nutrients
• development or worsening of disordered eating behaviors

Notably, food sensitivity tests are not a replacement for a personalized care plan from a registered dietitian or gastroenterologist.

The field of food sensitivity testing is constantly evolving, and new research is emerging regularly. It is possible that more accurate at-home food sensitivity testing methods may become available in the future.

If you believe you have a food sensitivity or are experiencing unexplained symptoms, the following two steps may help you identify the cause:

• Start a food and symptom journal: This can help you notice patterns to determine whether certain ingredients may be causing digestive issues or other symptoms. If you prefer not to keep a written record, several apps can make logging more convenient.
• Make an appointment with a doctor or dietitian: A health professional can help you rule out other potential causes of symptoms and determine whether you may have a food allergy or intolerance.

A healthcare professional may recommend an elimination diet, which involves removing potential trigger foods from your diet and reintroducing them slowly to determine which ones may contribute to your symptoms.

Because this diet can be restrictive, time-consuming, and difficult to follow, you should attempt it only with the supervision of a registered dietitian or another qualified health professional.

If you need help finding a primary care doctor, check out our FindCare tool here.

According to David D. Clarke, board certified gastroenterologist and president of the Psychophysiologic Disorders Association, many conditions may cause symptoms that can be incorrectly attributed to food sensitivity, including irritable bowel syndrome, inflammatory bowel disease, gallstones, and peptic ulcer.

Other potential culprits include:

• Stress: Feeling stressed can cause symptoms like digestive issues, headaches, dizziness, and difficulty concentrating.
• Dehydration: In addition to dizziness, lightheadedness, and fatigue, not drinking enough water can also lead to issues like constipation.
• Sleep deprivation: Getting poor or inadequate sleep can cause brain fog, trouble focusing, and digestive symptoms.
• Medications: Certain medications can cause side effects that may be similar to symptoms of a food sensitivity, including nausea, diarrhea, headaches, runny nose, and fatigue.
• Dietary habits: What you eat and drink can greatly affect your digestive system and may contribute to issues like bloating. Some nutritional deficiencies can also contribute to brain fog, fatigue, and depression.
• Food intolerance: Food intolerances may result in GI-related symptoms if your body cannot digest certain foods. Common sources of food intolerance include lactose, caffeine, sulfites, certain food additives, and fructose, which is a type of sugar found in fruits.

If you experience discomfort after eating certain foods, it’s important to rule out food allergies, which can be more severe than food sensitivities or intolerances.

Food allergies can cause serious symptoms, including hives, itching, swelling, and digestive issues.

In some cases, food allergies may lead to anaphylaxis, which can be life threatening.

When testing for food allergies, a doctor will likely collect information about your symptoms, diet, and medical history.

Doctors commonly use certain tests to diagnose food allergies:

• Skin test: This type of test involves pricking your skin with a probe that contains a small amount of food allergen and monitoring your reaction.
• Blood test: This test helps determine whether you are allergic to specific foods by measuring the amounts of certain antibodies in your blood.
• Oral food challenge: This procedure involves consuming small amounts of a suspected allergen under the supervision of a doctor. They will keep emergency equipment and medication on hand in case of a severe reaction.
  

For people who suspect they may have mild food allergies, an at-home food allergy test may be a convenient first step in identifying potentially problematic foods.

Most of these tests require a blood sample, which can be collected at home using a finger prick collection method or at a service center by a trained professional. This is then typically mailed to a lab for testing. The results are provided online within a few days or weeks.

It’s important to state that these at-home tests are not definitive — only a medical examination can diagnose a true food allergy. There are also concerns about the high rate of false positives with many at-home allergy tests.

While at-home allergy tests cannot provide conclusive answers about your symptoms, they may reveal a likelihood of you having a food allergy, which you can discuss more in-depth with a doctor.

If you’re interested in trying a food allergy test for yourself, you might consider one of these:

At-home food allergy tests

• Everlywell Food Allergy Test
• Labcorp Food Allergy Test
• Quest Health Food Allergy Test Panel

How do doctors test for food sensitivity?

If you’re experiencing symptoms of a food sensitivity, a doctor can help rule out other causes, including food allergies, using a blood test. They might also consider whether diet or lifestyle factors, or other underlying medical conditions might be playing a role.

Your doctor might also recommend an elimination diet, which can help identify food sensitivities when you remove potential trigger foods from your diet and reintroduce them gradually. This helps you and your doctor understand which foods may be contributing to your symptoms.

Are food sensitivity tests worth the hype?

There are concerns about the accuracy and reliability of food sensitivity tests, and they are not currently recommended by organizations like the Canadian Society of Allergy and Clinical Immunology and the AAAAI.

However, they could be useful to help identify potential trigger foods when used alongside other tools, such as a food and symptom journal.

At-home food sensitivity tests are not currently considered a reliable or accurate method of diagnosing food sensitivities.

Therefore, if you suspect you have a food sensitivity, it’s best to consult a health professional such as a doctor or registered dietitian.

In addition to ruling out other possible causes of your symptoms, such as food allergies or intolerances, a professional can determine the best course of treatment and provide guidance on necessary dietary changes.