Food intolerance tests
Food allergy versus food intolerance
Diet is a key component of a healthy lifestyle. Beyond consuming the recommended daily servings from the necessary food groups, it is important to know what foods, if any, you should avoid. Food allergies and intolerances (or sensitivities) affect many of us, and it is essential to know the differences. Food allergy involves an abnormal immune reaction to a non-pathogenic substance.
The body reacts as if it is fighting a disease-causing microorganism, which can cause symptoms ranging from malaise to life-threatening anaphylaxis, and may include abdominal pain, diarrhoea, vomiting, hives, swelling of the lips and face, difficulty breathing. , dizziness, low blood pressure, anxiety, and heart failure. Food allergies can affect up to 5-6% of young children and 3-4% of adults in Westernized countries. About 7% of Canadians self-report a food allergy.
Food intolerance is an adverse reaction to food that probably originates in the gastrointestinal tract and does not involve the immune system. This umbrella term includes lactose intolerance and non-celiac gluten intolerance along with a wide range of other sensitivities. The symptoms are not life-threatening and are generally limited to digestive symptoms such as diarrhoea, bloating, and nausea. Symptoms can appear shortly after eating or can take up to two days.
History and facts of allergies
Allergies include conditions such as hay fever, atopic dermatitis, and allergic asthma. Common allergens include a variety of foods, pollen, dust, animal dander, insect bites, certain medications, perfumes and fragrances, and many other substances. Even ubiquitous foods like lettuce can trigger an allergic reaction.
Depending on the severity of a person’s allergy, inhalation, oral consumption, and even touch can trigger a reaction. Drug allergies can be very serious. The most common drug allergens include penicillin, sulfonamides, and non-steroidal anti-inflammatory drugs (NSAIDs). Seek immediate medical attention if you suspect an allergic reaction to a drug.
Allergy testing and treatment
The gold standard for diagnosing allergies involves the skin prick test or the patch test. The skin prick test and the patch test are similar in that the examiner applies allergens to the skin and then measures the patient’s reaction to determine the allergic reaction. Skin prick and patch tests are the least expensive and easiest method of diagnosing allergies for most people. Immediate results are available after the test is complete. There are also blood tests to diagnose allergies. They are ideal for people who cannot perform skin tests.
However, blood tests cost more than skin tests and patches and are less sensitive. This means that a skin prick or patch test may produce a positive result and a blood test may produce a negative result in the same patient. Unlike skin-prick and patch tests, a patient may have to wait seven days or more for the results of a blood test.
The best form of treatment for allergies, especially food allergies, is avoidance. In the event of an allergic reaction, there are some treatment options available depending on the severity of the reaction. For severe reactions, epinephrine injection, given with an EpiPen®, is the first step in treating anaphylaxis, as the drug quickly reverses the effect of the attack. Give an injection of epinephrine, then call 9-1-1 and notify emergency services that someone is having an anaphylactic reaction.
Give a second dose of epinephrine five minutes after the first dose if symptoms do not improve. You should seek medical attention at the nearest hospital, even if symptoms improve after the first or second injection. Antihistamines and corticosteroids can treat the mildest symptoms (more common in non-food allergies) of an allergic reaction, but not anaphylaxis.
Food Intolerance Test: Does It Work?
Reputable food allergy tests are available through specialist physicians known as allergists or immunologists, but there are no reliable tests for food intolerances. However, some independent laboratories have produced their own blood test systems that they claim can identify food intolerances, which are available at a select number of retail pharmacies or health food stores. However, the medical science community has raised concerns regarding the efficacy of these test systems, so doctors will rarely ask you to perform these often expensive tests that produce questionable results.
The Research Committee of the College of Physicians of Quebec (CMQ) cautions against medical professionals recommending these test systems to their patients. The Committee notes that laboratories promoting food intolerance testing present unvalidated conclusions. They reaffirm the duty of licensed medical professionals to administer any type of test only when medically necessary, and that there is a greater need to be critical of data that comes from unrecognized sources or promotional material.
The Canadian Society for Allergy and Clinical Immunology says: “There is nobody of research to support the use of [these] tests to diagnose adverse reactions to food or to predict future adverse reactions.” They issued their position in support of similar views expressed by the American Academy of Allergy, Asthma, and Immunology and the European Academy of Allergy and Clinical Immunology regarding the validity of food intolerance tests.
We all want to know what foods to avoid, especially when it comes to eating something that could result in a life-threatening allergic reaction. Food intolerance testing systems can be expensive and are based on data that the medical scientific community does not support. Making drastic changes to your diet based on this unproven evidence could lead to health problems, such as nutritional deficiencies. If you are concerned about dietary options and possible allergy or sensitivity to a particular food, you should consult your GP for a referral to a qualified specialist.
Five facts about allergy
- The Viennese paediatrician Clemens von Pirquet introduced the concept of allergy in 1906 after noticing hypersensitivity in his patients to seemingly innocuous substances such as dust, pollen, and certain foods.
- The word “allergy” derives from the ancient Greek words allos (meaning “other or different”) and Energia (meaning “energy or reaction”).
- Most food allergies are the result of an immune response to certain proteins found in some foods. These proteins trigger the release of anti-inflammatory chemicals, including histamine.
- Health Canada created a list of priority allergens that require specific labelling guidelines. The current list includes eggs, milk, peanuts, tree nuts, wheat, shellfish, sesame, soy, sulphites, and mustard.
- Food allergens can appear in unexpected places, including processed foods, vitamins, skin creams, and pet food. Always read a food’s label and ingredient list carefully to make sure it is free of food allergens that could be harmful to you or your family.