Have you ever wondered if you have sensitivities to what you are eating? There is a HUGE focus on food sensitivities and intolerances in pop culture these days. It can seem like just eliminating the wrong food will ‘click’ you into the life you have always wanted. It’s normal to search for answers to things like poor digestion, low energy, brain fuzz and mood fluctuations. But as people continue to search for solutions to all that ails them, there may be an over-focus in this area. Diet is a great place to start looking, but it is only the beginning of your journey.
There is a lot of confusion over food sensitivity testing and what are accurate results that have meaning in your life vs. meaning on paper. Food Allergies, intolerances and sensitivities are three terms that are often used interchangeably to describe a number of symptoms However, they are totally different. Allergies and intolerances are more typically described and tested. But more recently the term “food sensitivity” has been attributed as a cause of a range of conditions such as digestion issues, headaches, and even mental health symptoms.
Given how poorly-defined the idea of “sensitivity” is, and the MANY different ways of testing these sensitivities that have emerged (holding vials of foods, blood analysis, electro-acupuncture), we think it deserves some focus. Here we breakdown the difference between food allergies, intolerances and sensitivities, and how they can be reliably tested. We also look at their meaning in the context of your health, and the harm of self or inaccurate diagnosis.
What's the Difference?
A true food allergy is an IgE mediated immune system reaction to food. IgE is an antibody that reacts to the presence of a particular food, and sends signals for the immune system to react and attack. This response triggers histamine production, and typical symptoms include an atopic (skin) reactions of swelling and hives, possible breathing issues, and sometimes digestive distress. The most serious reaction is anaphylaxis. Common food allergens include eggs, peanuts and dairy.
People with the autoimmune condition Celiac Disease have an allergy to gluten, one of many proteins found in grains. Those with Celiac may not have symptoms of allergic response, however if they continue to eat gluten unknowingly, it can be very harmful in the long-term. If you suspect Celiac Disease, accurate testing is important, otherwise you may be at increase risk of complications from not properly eliminating gluten. To receive an accurate blood test, you must “gluten-load” for 8 weeks prior to your test! Many people do not do this, and therefore end of with false results.
This is not the same as a food allergy because it is not the result of the IgE immune response. Rather, this is something else in the body that prevents it from tolerating certain foods. In many cases, this may be the lack of an enzyme needed to break down and process certain foods. The most common is lactose intolerance, resulting from low levels of lactase enzyme in the liver. Most adults stop producing high-levels of lactase, the enzyme that processes lactose (a sugar found in all mammalian milks, including breastmilk!). If you consume small amounts of lactose consistently, you will house that enzyme in your liver.
Other examples of intolerances include alcohol (lack of alcohol dehydrogenase). Or, an inability to break down certain saccharides, that might lead someone to avoid beans and lentils (low FODMAP diet). These conditions usually cause symptoms with digestion and our skin.
There is a lot more variability to the definition of a sensitivity, and that definition can be used in many different ways. At its most basic, a food sensitivity suggests your body is triggered with some digestive issue that seems to be related to timing of when you ate a certain food. It could be that something gives you heartburn, you have bloating or you react strongly and immediately to something, like caffeine. Non-celiac gluten-sensitivity (NCGS) falls into this category as well. This is where someone has symptoms from consuming gluten, and elimination of symptoms when they remove gluten from the diet, but do not have the same level of intestinal damage caused by Celiac Disease.
Sensitivities are hard to test for, and tests are oversimplified. For example, showing a positive result on a food sensitivity test does not indicate which epitope of an immunoglobulin is triggered. This is a fancy way of saying, your body will show a positive result BECAUSE you have been exposed to a food before and it’s familiar to your immune system. This doesn’t mean you are “sensitive” to it.
IgG Food Sensitivity
One main type of food sensitivity testing is based on IgG antibodies in the blood. This is not the same IgE, the antibody that shows an allergy. Here’s the issue with IgG food sensitivity testing: it isn’t accurate and it doesn’t really show the detail that is needed (i.e. epitopes) to determine a conclusion. IgG antibodies in increased levels do not mean there is any sensitivity, but rather that there has been singular or repeat exposure to that food. That is not a good reason to cut out a food, and certainly not evidence that dozens of symptoms are being caused by those foods.
Another issue is the clinical or life-relevance of these tests. Many clients get false positive results for foods they are supposedly sensitive to, even though they don’t have symptoms. If something doesn’t have clinical meaning (makes you feel sick), then it doesn’t have meaning at all, unless it is a true allergy. Ruling out all other causes is often how they are diagnosed. Sometimes individuals become hyper-aware and hypersensitive to their own digestive tract, meaning symptoms are actually coming from the nervous system, as opposed to any food response over time. This builds over time, especially if you focus on it.
There is a “new school” of thought that associates food sensitivities with multiple illnesses and conditions- even if you don’t have specific skin or digestive reactions to that food. Along with this, new tests have sprung up to measure your body’s “sensitivity” to food, which often come with surprising results. These tests are based on numerous health and alternative medicine ideas and are listed below.
If you suspect that you or your child have a food allergy, seeking out a doctor is the first step. Based on what you have described, they will likely use on of the following tests to determine if you have an IgE mediated food allergy.
Types of Allergy/Intolerance/Sensitivity Testing:
Here is a list of common types of tests that you might hear of in association with food allergies, intolerances and sensitivities. They are carried out by a variety of professionals depending on the nature of the test, such as doctors, nurses, dietitians, nutritionists, naturopaths, and more.
Skin Prick Test
Tests for allergies. A small amount of an allergen is placed on the skin, and the skin is pricked to expose the body. Positive results are indicated by raised white bump surrounded by red itchy skin, kind of like a mini allergic reaction. The skin prick test rarely shows false negatives, but can have false positives based on foods with similar proteins, and more exposure in the skin and blood than would normally happen in the digestive process. Still, in combination with personal history, they can be very helpful and diagnose accurately.
Serum blood tests are clues for allergies. They take longer than a skin prick test, but can be done in cases where a skin test is not possible. Like the skin test, bloodwork measures IgE antibodies to food, and has the same minimal chance of false negatives but a higher chance of false positives.
Oral Food Challenge
This is a test for suspected food allergies. This is considered the most accurate allergenic testing and should only be done by a professional allergist as a reaction can occur. There are important guidelines and standards for this protocol, but it’s the most reliable. It involves actually giving a person doses of the possible allergen in increasing amounts and monitoring their reaction. The gold standard method involves a double-blind placebo, meaning the patient is given the allergen and placebo, not knowing which is which- for example having a product with and without milk added.
Trial Elimination Diet
These can test for allergies, intolerances, and sensitivities. This might go along with the skin prick or blood test, to test whether symptoms clear up when an allergen is removed and reappear when reintroduced. It generally lasts 2-8 weeks, but is dependent on specific symptoms present. Elimination diets must be individualized and carefully designed to not remove too many calories and cause physical and psychological stress.
If you are tested and no true food allergies are found, your doctor may consider the possibility of an intolerance or sensitivity, depending on your symptoms. Unfortunately, some conditions such as Irritable Bowel Syndrome (IBS) are often only diagnosed as a result of ruling out all other possible causes, and confirming based on a person’s symptoms, which are very subjective. This can be a frustrating process, which has led many to seek alternative tests to determine the causes of their symptoms. These tests tend to be expensive (and paid for out of pocket) and have little scientific validity. Here are some of the common ones:
These test for sensitivities. You may recognize this also as Hemocode, which can be administered at some pharmacies, despite the lack of validity. Instead of measuring the traditional antibody for food allergies, it measures IgG- an antibody which increases with exposure to foods, not with allergy. IgG antibodies have not shown any association with disease, mental or physical illness, and have even in some cases shown to be protective.
These test for allergies/sensitivities. This adds samples of white blood cells onto a slide with dried food particles of particular allergens. According to the test, if there is a change in the cells, it indicates a food allergy. It actually doesn’t, as there is no scientific basis for this test. Results fluctuate considerably from day to day and based on who is running the test.
This test claims to test for sensitivities. This test is described as “a traditional and time-tested, authentic test”, however it’s not correlated to anything other than placebo. The person holds a conductor and small currents are applied to acupuncture points that are connected with vials of the tested foods. The reading is supposed to tell you which foods you are sensitive to and should avoid. There is very limited evidence on this, and the studies that have been done could not distinguish the difference between those with and without allergies or sensitivities.
Supposed to test for sensitivities. This seems to be particularly strange, but apparently is real. The idea is that if something is harmful to the body, it would show up in the hair. While hair can sometimes show some of the mineral make-up of the body, results were varied across different labs. Sometimes hair-loss is a symptom of iron-deficiency or hormonal changes when you are pregnant or postpartum. But hair grows very slowly, and the analysis of a strand cannot be considered representative to what is happening in the body related to long-term or acute nutrition issues.
Risks Associated with Sensitivity Testing
This is only a small portion of testing techniques claiming to know what you’re allergic or sensitive to- some test pulse, muscle strength, and even claim to be able to cure your sensitivities. In reality, these are unvalidated and can be downright dangerous. Here’s why:
Unnecessary Food Restriction is incredibly harmful, especially in children. Cutting out otherwise healthy foods because a test, not your actual symptoms, told you to can put you at risk for nutritional deficiencies. And it just makes life hard! If your kid has finally decided that they are not weirded out by a vegetable and some alternative test then tells you to avoid it- get a second opinion.
False results could miss a food allergy. If you really have an allergy and an unvalidated test doesn’t catch it, you’re putting yourself at risk of reaction. If you have been having traditional symptoms of food allergies- see a doctor who can refer you to an allergist for proper testing.
It’s a waste of money. This isn’t so much an immediate danger, but it’s still an important point. Food prices are skyrocketing, and we’re sure you have better places to spend that money.
Bottom-Line: It’s a waste of money, that may give you pretend results and false hope. Start tracking your diet with a diary and trial a food elimination if you want to assess symptoms yourself, and save some cash! Remove only 1 food per elimination, and keep the food removed for 2 weeks before you reintroduce it. With groceries, food and everything else skyrocketing in price, I’m sure there are more valuable things you could do with that money.