Food Allergy, Sensitivity vs Intolerance: What's the Difference?
One of the most common questions I get asked is what’s the difference between a food allergy, sensitivity and intolerance?
This is an important question because if you have been avoiding foods due to fatigue or digestive issues, understanding the root of food reactions is essential to addressing these symptoms.
Many food reactions are actually symptoms of an underlying imbalance. But the good news is that when digestion is functioning better, a wide variety of foods can be tolerated.
Let’s start with the difference between food sensitivities, intolerances, and allergies:
Food Allergy
With a food allergy, your immune system identifies that food as an invader and signals the release of IgE antibodies. Food allergies involve a fairly immediate reaction, which can be serious and life threatening. An example of this is someone with a peanut allergy experiencing anaphylactic shock in response to eating peanuts.
If someone has an allergy, it means that they would have to stay 100% free from the food in order to control reactions. In some cases cross-contamination, such as foods that were prepared close to nut-containing foods, can expose people to enough of the food to cause an allergic reaction.
Food allergies are often diagnosed through blood testing and/or skin prick tests by a healthcare professional specializing in food allergies.
Food Sensitivity
Food sensitivities on the other hand can be harder to pinpoint. Similar to allergies, they involve the immune system. But the difference is food sensitivities trigger IgG or IgM antibodies, and a reaction can take up to three days after eating the food. Another big difference is that food sensitivities are often dose-related, which means some people can tolerate a small amount of the food without showing symptoms.
Common symptoms of food sensitivities include:
Abdominal aches
Gas
Bloating
Headache
Fatigue
Brain fog
Joint pain
Acne
Eczema
Food sensitivities are increased when the gut lining becomes permeable (aka. "Leaky Gut") and healing that gut lining will reduce the number of food particles that can enter your blood and activate your immune system. Rest, sleep, and stress management can all come into play in how our gut expresses food sensitivities.
While IgG Food Sensitivity Tests are popular and can provide information on what foods to pay attention to, I am not a fan of these. IgG Food Sensitivity Tests often provide false positives, are not always correlated with symptoms, and may still involve trial and error to see what works best for your body.
Instead, it may be more helpful to focus on restoring the gut lining and addressing the root cause of the gut imbalance.
Food Intolerance
Food intolerances are not related to the immune system, which means that they do not involve the release of antibodies. A food intolerance is directly related to your body’s ability to digest a specific food. With food intolerances, the reaction will occur after eating the food and only lasts until the food exits your body. A common example of food intolerance would be lactose intolerance which causes gas, bloating, and diarrhea after drinking milk. Lactose tolerance happens because the body doesn’t produce enough of the enzyme lactase to break down the milk sugar called lactose
Eating less of that food or having it less frequently may help with symptoms, depending on how your body reacts to it.
However, it is also important to consider any underlying conditions that also need to be addressed. For example, those with IBS often have a FODMAP intolerance, which can occur due to an overgrowth of microbes in the gut leading to symptoms like gas, bloating, constipation or diarrhea.
