Do you experience frequent abdominal issues, brain fog, sinus problems, or even mysterious skin rashes? It could be something you ate! Food sensitivities have become a hot topic in the world of integrative health, particularly since they appear to be on the rise. (5) According to some estimates, food sensitivities impact up to 20% of the total population. (20) If you think a food sensitivity may be at the root of your symptoms, you can try an elimination diet in an effort to pinpoint the food(s) responsible. Or you might consider taking a food sensitivity test. However, because the science is still in its infancy, the question remains—are food sensitivity tests accurate?
What are food sensitivities?
Before we unpack the pros and cons of food sensitivity testing, let’s explore how food sensitivities differ from food intolerances and allergies. Although the terms are often used interchangeably, food intolerances, food allergies, and food sensitivities aren’t the same thing.
If someone has a food intolerance, you might hear them mention that certain foods or ingredients like cruciferous vegetables, dairy products, or food additives don’t agree with them. Officially defined as having trouble digesting certain foods, intolerances don’t involve the immune system. They can, however, cause digestive upset just a short time after eating the offending food. (6)(9) The likely culprit behind food intolerances is a lack of digestive enzymes needed to break down certain foods. (5) Because of this, food intolerances are dose dependent—the more you eat, the worse your symptoms. (11)
True food allergies, on the other hand, cause an immune system reaction to a protein typically found in one of the following eight foods: cow’s milk, eggs, fish, peanuts, tree nuts, shellfish, soy, and wheat. (21) If you eat a food you are allergic to, your immune system sees the allergen as a threat and mounts a response via an inflammatory pathway called IgE. While eating even minute amounts of a food allergen can spark acute mild to severe skin or respiratory symptoms, it can also provoke anaphylactic shock, a condition that can be fatal. (4)(6)
Food sensitivities also involve the immune system. Eating a food you’re sensitive to initiates an inflammatory response via the IgG inflammatory pathway. (16) Recent research has linked the development of food sensitivities to imbalances in the gut microbial community (microbial dysbiosis), which sparks the immune response and subsequent inflammation. (5)(19) Unlike a true food allergy, which causes an immediate reaction, food sensitivities activate one important type of immune cell (leukocytes) and can cause a delayed response. (10)(15) This means symptoms can occur hours or even days after the offending food is eaten.
Did you know? Women appear to be more likely than men to develop food sensitivities. (2)
Possible symptoms of a food sensitivity
Because the following symptoms may also indicate a food intolerance, food allergy, or a problem unrelated to the foods you eat, it’s wise to consult with your healthcare practitioner.
Common symptoms associated with food sensitivities include:
- Abdominal discomfort including gas and bloating (5)
- Diarrhea (5)
- Headache/migraine (22)(23)
- Nasal congestion (3)
- Skin reactions (dermatitis herpetiformis) that include blisters, welts, itching, and/or redness (12)
Do food sensitivity tests work?
Food sensitivity testing is a fairly new area of research. As such, it is often dismissed by traditional allergists or simply mislabeled as a food intolerance. (1) However, even though the underlying mechanisms that cause sensitivities remain elusive, some studies lend credibility to testing. (5) But, before you sign up for food sensitivity testing, it’s wise to look at the pros and cons.
Some of the benefits of food sensitivity testing include:
- Can test a large number of foods for adverse reactions from a single sample
- May help to identify specific foods causing symptoms
- Results can be obtained faster than those uncovered via a traditional elimination diet
- Some types of food sensitivity tests can be ordered directly by consumers and do not require working with a healthcare practitioner (14)
However, some of the drawbacks to these tests include:
- Can’t be customized to test for specific foods
- Can be expensive
- Considered laboratory-developed tests and not regulated by the Food and Drug Administration
- Lacks a significant amount of randomized controlled research
- May not be covered by insurance; however, some tests may be eligible under Flexible Spending Accounts (FSA) or Health Spending Accounts (HSA) plans
- Not standardized (8)
Different types of food sensitivity tests
Tests designed to uncover food sensitivities abound, but they aren’t one size fits all. Many popular food sensitivity tests measure IgG antibodies against a variety of foods using a blood sample. According to researchers at Johns Hopkins University School of Medicine, testing for IgG provides clinically-meaningful results. (17)
Cell-based testing is another option. These include leukocyte cellular antibody tests (ALCAT) and mediator release tests (MRT). While both ALCAT and MRT testing are designed to assess changes to your white blood cells in response to certain food antigens, they differ in key ways. The ALCAT test pinpoints specific foods that trigger the release of DNA by a type of white blood cell known as innate immune peripheral blood leukocytes. (10) In one recent study that appeared in the journal Alternative Therapies in Health and Medicine, researchers found that ALCAT correctly identified a genetic mutation in people with insulin resistance, signaling a sensitivity to dietary sugars. (18) Another study published in Clinical Nutrition ESPEN reported that the ALCAT test was useful in determining non-celiac gluten sensitivity. (7)
MRT testing measures the levels of cellular mediators like cytokines, histamine, leukotrienes, and prostaglandins that are directly associated with inflammation. In one 1997 study, Polish researchers noted that MRT testing has a 94.5% sensitivity for identifying cellular reactions to harmful antigens that can signal a food sensitivity. (13) However, at this time, there is little peer-reviewed published data documenting the accuracy of MRT.
Did you know? Some food sensitivity tests use strands of hair or a cheek swab. However, these tests do not look at IgG antibodies or cellular reactions to identify food sensitivities and may not be accurate.
Best food sensitivity tests
There are numerous food sensitivity tests on the market. Some require a blood draw similar to that conducted by a lab. Others just require a blood sample obtained with a prick test. Most tests require that you continue eating the foods you suspect of causing problems for accurate results. Depending on the type of test and how many foods are tested, prices can range from $99 to $1,500. Consider working with a healthcare practitioner who can help you pick the best food sensitivity test for your specific needs. As a bonus, they can also help you interpret and implement the findings.
The bottom line
Although there are few randomized, placebo-controlled studies documenting the efficacy of food sensitivity testing, they may provide clues to the underlying cause of your symptoms. This can be especially useful if symptoms don’t occur until several days after the sensitizing food is eaten. Although some types of food sensitivity tests don’t require working with a healthcare practitioner, doing so may help you choose the best test for your individual situation.
- AAAAI support of the EAACI Position Paper on IgG4* (2010). American Academy of Allergy Asthma & Immunology. https://www.aaaai.org/Aaaai/media/Media-Library-PDFs/Tools%20for%20the%20Public/Conditions%20Library/Library%20-%20Allergies/eacci-igg4-2010.pdf
- Acker, W.W., Plasek, J.M., Blumenthal, K.G., Lai, K.H., Topaz, M., Seger, D.L., Goss, F.R., … Zhou, L. (2017). Prevalence of food allergies and intolerances documented in electronic health records. The Journal of Allergy and Clinical immunology, 140(6), 1587–1591.e1.
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- Caminero, A., Meisel, M., Jabri, B., & Verdu, E.F. (2019). Mechanisms by which gut microorganisms influence food sensitivities. Nature Reviews: Gastroenterology & Hepatology, 16(1), 7-18.
- Crowe S.E. (2019). Food allergy vs food intolerance in patients with irritable bowel syndrome. Gastroenterology & Hepatology, 15(1), 38–40.
- Di Stefano, M., Pesatori, E.V., Manfredi, G.F., De Amici, M., Grandi, G., Gabriele, A., Iozzi, D., & Di Fede, G. (2018). Non-Celiac Gluten Sensitivity in patients with severe abdominal pain and bloating: The accuracy of ALCAT 5. Clinical Nutrition ESPEN, 28, 127-131.
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- Garcia-Martinez, I., Weiss, T.R., Yousaf, M.N., Ali, A., & Mehal, W.Z. (2018). A leukocyte activation test identifies food items which induce release of DNA by innate immune peripheral blood leucocytes. Nutrition & Metabolism, 15, 26.
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- König, B., Koch, A.N., & Bellanti, J.A. (2021). Studies of mitochondrial and nuclear DNA released from food allergen-activated neutrophils. Implications for non-IgE food allergy. Allergy and Asthma Proceedings, 42(3), e59–e70.
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- Pompei, P., Grappasonni, I., Scuri, S., Petrelli, F., Traini, E., Sorrentino, S., & Di Fede, G. (2019). A clinical evidence of a correlation between insulin resistance and the ALCAT Food Intolerance Test. Alternative Therapies in Health and Medicine, 25(2), 22-38.
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