Food Allergy vs. Sensitivity vs. Intolerance – What’s The Difference?
Food sensitivity testing (FST) is a blood test many naturopathic doctors do in practice to measure the level of an immune response a patient has to certain foods. With the increasing evidence on the link between your gut and many chronic diseases, this can be a very useful tool in finding the root cause of your health concerns. Consumption of foods that your body negatively reacts to initiates an inflammatory cascade that can contribute to many skin conditions (eczema, psoriasis, acne, etc), cognition problems (poor memory, concentration and focus issues, etc), osteoporosis/arthritis, joint pain, asthma, weight gain, fatigue, as well as gut concerns (including poor nutrient absorption, constipation/diarrhea, bloating, etc), and many more.
There is some resistance in the medical community about this test, and a large part of this is because many don’t understand what FST is truly measuring. First and foremost, even though the test is measuring an immune response, it is NOT indicating a true “allergy”. There are specific tests that the conventional medical system does (such as the skin prick test) that DOES measure an allergic response. Confused? Take a read below as I dive into what a food allergy vs. sensitivity vs. intolerance is.
Food Allergy
- Indicates IgE immune response i.e. measures an immediate TRUE food allergy (type I hypersensitivity reaction)
- Requires at least one previous ingestion of the food
- Consuming small amounts of food can trigger a reaction
- Rapid onset of symptoms (i.e. within minutes), but brief duration
- Common symptoms include itchy/watery eyes, rash, difficulty breathing, swelling
*Note: FST is not used to diagnose Celiac diease. Diagnosis of Celiac involves more extensive testing.
Food Sensitivity
- Indicates IgA (mucosal hypersensitivity reaction) or IgG (type III hypersensitivity reaction) response i.e. measures a DELAYED immune response
- Usually a reaction to commonly consumed foods
- Reaction is dose dependent (a more reactive food will cause a greater response)
- Delayed onset of symptoms, and prolonged duration (i.e. days to months)
- Common symptoms include headaches, brain fog, fatigue, constipation/diarrhea, skin lesions, body aches/pains, weight gain
Food Intolerance
- Indicates a lack of enzyme needed in order to digest the food i.e. DOES NOT measure an immune reaction
- A common intolerance is lactose intolerance, whereby the enzyme needed to digest dairy (i.e. lactase) is deficient in the individual, causing symptoms such as gas, bloating, and diarrhea upon consumption of the food
- Symptoms are usually improved or alleviated with the use of digestive enzymes specific to the intolerance (e.g. if you have a lactose intolerance, your body would need lactase enzymes)
- Can be an immediate or delayed response, depending on how deficient you are in the enzyme and how much of the food you consume
- Common symptoms include bloating, constipation/diarrhea, general digestive upset, fatigue after the meal
If you have health concerns that have not gotten better with time and are continually interfering with your quality of life, it may be time to look at your gut. Food sensitivity testing gives you specific answers and a clear path to treatment.
The elimination diet is another way to determine what foods you are reacting to, however it is a challenging and lengthy process, so you must be ready for it. There are pros and cons to each method – it is best to speak to a naturopathic doctor to determine the most appropriate individualized treatment for you, depending on your lifestyle and health goals.
