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Food sensitivities have become a hot topic in the world of whole-person health, particularly since they appear to be on the rise. (Caminero 2019) According to some estimates, food sensitivities impact up to 20% of the total population. (Shakoor 2016) If you think a food sensitivity may be at the root of your patient’s symptoms, they can try an elimination diet to pinpoint the food(s) responsible. Or you might consider recommending a food sensitivity test. However, because the science is still in its infancy, the question remains—are food sensitivity tests accurate?

Trying to decipher what foods are triggering symptoms can be frustrating. Food sensitivity tests may help eliminate the guesswork. 

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. (Crowe 2019)(NHS 2022) The likely culprit behind food intolerances is a lack of digestive enzymes needed to break down certain foods. (Caminero 2019) Because of this, food intolerances are dose-dependent—the more a person eats, the worse the symptoms. (Gargano 2021) 

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. (Food Allergy Research & Education) If a person eats a food they’re allergic to, their 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. (Crowe 2019) 

Food sensitivities, which also involve the immune system, initiate an inflammatory response via the IgG inflammatory pathway. (Lavine 2012) 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. (Caminero 2019)(Rotondi Aufiero 2018) 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. (Garcia-Martinez 2018) This means symptoms can occur hours or even days after the offending food is eaten.

Did you know? Women may be more likely than men to have food sensitivities. (Acker 2017)

When a person eats a food they’re sensitive to, it may trigger gastrointestinal problems or other symptoms that may not immediately point to their diet.

Possible symptoms of food sensitivity

Because the following symptoms may also indicate a food intolerance, a food allergy, or another problem unrelated to food, it’s important for patients to consult their healthcare provider. 

Common symptoms associated with food sensitivities include:

• Abdominal discomfort, including gas and bloating (Caminero 2019)
• Diarrhea (Caminero 2019)
• Headache or migraine (Martin 2016)(Xie 2019)
• Nasal congestion (Al-Rabia 2016)
• Skin reactions (dermatitis) that include welts, itching, and/or redness (Katta 2014)

Do food sensitivity tests work?

Food sensitivity testing is a fairly new area of research. As such, it's often dismissed by traditional allergists or simply mislabeled as a food intolerance. (AAAAI 2010) However, even though the underlying mechanisms that cause sensitivities remain elusive, some studies lend credibility to testing. (Caminero 2019) But before recommending food sensitivity testing, it’s important to understand the pros and cons.  

Pros

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 (LaHood 2019)

Cons

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

Patients can do a food sensitivity test at home. Some only require a simple finger prick to collect a blood sample.

Different types of food sensitivity tests

What's the best food sensitivity test? There are various types of food sensitivity tests, but they aren’t one-size-fits-all. Many popular food sensitivity tests measure IgG antibodies against various foods using a blood sample. According to researchers at Johns Hopkins University School of Medicine, testing for IgG provides clinically meaningful results. (Mullin 2010)

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. (Garcia-Martinez 2018) 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. (Pompei 2019) Another study published in Clinical Nutrition ESPEN reported that the ALCAT test was useful in determining non-celiac gluten sensitivity. (Di Stefano 2018)

Mediator release testing (MRT) measures the release of chemical mediators by white blood cells upon exposure to food antigens. It measures the levels of cytokines, histamine, leukotrienes, and prostaglandins associated with inflammation. More well-controlled trials confirming the efficacy of the MRT tests are necessary to solidify its use. (Wenger 2021)

Did you know? Some food sensitivity tests use strands of hair or a cheek swab. However, these tests don't look at IgG antibodies or cellular reactions to identify food sensitivities and may not be accurate. 

Which is the best food sensitivity test? 

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 patients continue eating the foods they suspect are 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.  

The bottom line 

Although there are few randomized, placebo-controlled studies documenting the efficacy of food sensitivity testing, these tests may provide clues to the underlying cause of 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 provider, doing so may help patients choose the best test for their individual situation.