You might be disappointed to learn that IgG food sensitivity tests aren’t reliable. Here, we discuss whether you may want to consider taking a food allergy test instead.
Quick look at food allergy tests
Figuring out if specific foods are causing unwanted symptoms is a complicated process, as food sensitivities are still not well understood. And, so far, no food sensitivity panel can accurately and definitively diagnose food sensitivities.
Food allergy tests, however, may provide information about foods that are potentially dangerous for you.
We’ll explain what we know about food sensitivities and why food allergies can be easier to diagnose. We also explore what else may be going on if you think your symptoms might be related to a specific food.
Food sensitivity vs. food allergy vs. food intolerance
The terms “food sensitivity,” “food allergy,” and “food intolerance” are sometimes used interchangeably, but they are not the same.
- Food sensitivity: Food sensitivities are believed to
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 your body in response to specific food or groups of foods. Symptoms may include digestive distress (gas, diarrhea, abdominal pain), joint pain, brain fog, and migraine. These symptoms may be subtle or may not happen right away. Food sensitivities are not life threatening. - Food allergy: This is a severe immune response to a food, which is often caused by increased production of an antibody called immunoglobulin E (IgE). Symptoms occur within 2 hours and
may include hives, tongue swelling, difficulty breathing or swallowing, and dizziness. Food allergies can be life threatening. - Food intolerance: This
occurs when your body lacks certain enzymes necessary to break down a food. It may cause stomach upset or other digestive problems, but it’s not related to your immune system and is not life threatening.
Are food sensitivity tests reliable?
In short: No. There’s limited evidence to support using a food sensitivity test at home.
Yet
What’s more, many of the studies that companies cite to support using these tests are outdated or have been published in unreputable journals.
Some tests claim to help you understand how your body may respond to certain foods based on factors such as your genetic background. However, the
Multiple organizations, including the
Notably, food sensitivity tests are not a replacement for a personalized care plan from a doctor or registered dietitian.
David D. Clarke, board certified gastroenterologist and president of the Psychophysiologic Disorders Association, explains that many GI symptoms incorrectly attributed to food sensitivity can be caused by conditions including irritable bowel syndrome, inflammatory bowel disease, gallstones, and peptic ulcer.
Could it be a food allergy?
If you experience symptoms, including hives, itching, and swelling after eating certain foods, it’s important to rule out food allergies, which can be quite serious. In some cases, food allergies may lead to anaphylaxis, which can be life threatening.
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.
Learn more about food allergy testing.
At-home food allergy tests
For people who suspect they may have mild food allergies, an at-home food allergy test may be a first step in identifying potentially problematic foods.
The “first step” part is important. At-home food allergy tests are not as comprehensive or conclusive as food allergy tests administered by a medical professional. In particular, there are concerns about the high rate of false positives associated with them.
At best, these tests may help reveal the potential for a food allergy, which can only truly be diagnosed by a doctor.
A note on at-home food allergy tests
The AAAAI does not currently endorse the use of at-home allergy testing. Additionally, at-home food allergy tests cannot officially diagnose a food allergy. Instead, they can help identify foods that you have the potential to be allergic to.
If your results suggest that you may have a potential allergy, make an appointment with an allergist to ensure accurate interpretation and establish a follow-up plan.
Finally, these tests are not suitable for people with severe allergy symptoms.
At-home food allergy tests
A note for New York residents
At-home test kits are not available to ship to New York state because of state regulations around testing.
Food allergy tests compared
Price | Type | Tests for | |
---|---|---|---|
Labcorp Food Allergy Test | $199 | in-person blood draw | egg white, milk, wheat, corn, codfish, clam, shrimp, scallop, peanut, walnut, soy, sesame seed |
Everlywell Food Allergy Test | $149 | at-home blood sample | almond, cow’s milk, egg white egg yolk, peanut, shrimp, soy, tuna, wheat |
Quest Food Allergy Test Panel | $179* | in-person blood draw | almond, cashew, codfish, cow’s milk egg white, hazelnut, peanut, salmon, scallop, sesame seed, shrimp, soy, tuna, walnut, wheat |
*Additional fees apply for in-home service. Price does not include $6 physician fee.
Other reasons you might be having GI symptoms
According to Clarke, many conditions may cause symptoms that can be incorrectly attributed to food sensitivity, including irritable bowel syndrome, inflammatory bowel disease, gallstones, and peptic ulcers.
Other potential culprits include:
- Stress: Feeling stressed can cause symptoms such as digestive issues, headaches, dizziness, and difficulty concentrating.
- Dehydration: In addition to dizziness, lightheadedness, and fatigue, not drinking enough water
can also lead to issues such as 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 such as 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.
What should you do if you think you have a food sensitivity?
- 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. They may also recommend an elimination diet to help identify potential trigger foods.
If you need help finding a primary care doctor, check out our FindCare tool here.
Frequently asked questions
It’s debatable. Food sensitivity tests measure the level of IgG antibodies in your blood after exposure to various food allergens. The higher the level of antibodies, the test companies say, the greater the chance of a food sensitivity.
But these tests are not widely accepted in the medical world. Many experts warn that the IgG measure is not an accurate or reliable marker of food sensitivity. There are also concerns about the high rate of false positives with the tests.
The American Academy of Allergy, Asthma & Immunology, for example, actually advises against using them.
So far, no food sensitivity test has earned approval of the Food and Drug Administration (FDA).
At this time, no food sensitivity test has been approved by the FDA. The best way to identify potential food sensitivities is by working closely with a registered dietitian or other qualified healthcare professional, who may recommend an elimination diet.
Except for lactose and fructose intolerances, which can be diagnosed using breath tests, there’s currently no validated biomarkers to test for food intolerances. Instead, food intolerances are generally diagnosed through elimination diets.
The Everlywell Food Sensitivity Test uses IgG levels to determine potential food sensitivities. However, the presence of IgG has not been proven to be an accurate or reliable marker of food sensitivity.
The bottom line
Taking a food sensitivity test at home is not currently considered a reliable or accurate method of diagnosing food sensitivities.
An at-food allergy test may reveal a potential for a food allergy, but only a medical doctor can provide a true diagnosis.
If you experience symptoms after eating certain foods, it’s best to talk with a health professional. They can rule out other potential causes, determine the best course of treatment, and provide guidance on necessary dietary changes.