The Difference Between Food Sensitivity, Allergy, and Intolerance
Eating should be an activity that brings pleasure and food should be something to get excited about, but when you're navigating food reactions it can be incredibly stressful. When I work with clients who have been avoiding foods due to digestive discomfort, my highest priority is increasing the diversity in their diet. Understanding the root cause of food reactions is an important part of this process.
The good news is that a lot of food reactions are actually symptoms of an underlying imbalance. When overall digestion is functioning better, you can comfortably tolerate a wide variety of foods.
When it comes to food reactions, there are three different types you need to know about:
1. Food Allergies
A food allergy is usually very obvious, and people with allergies know that they have allergies. Food allergies involve IgE antibodies and causes a reaction fairly immediately. True allergies can be serious and life threatening. A common example is peanut allergy where someone goes into anaphylactic shock as soon as they are exposed to peanuts.
If someone has an allergy, it means that they have to stay 100% free from the food they are allergic to. Even cross-contamination, for example eating a nut-free meal that was prepared close to nut-containing foods, can expose them to enough of the antigen to cause an allergic reaction.
While food allergies can sometimes be reduced in severity, this requires long-term therapy with someone who specializes in food allergies, in a highly controlled setting.
2. Food Sensitivities
Food sensitivities on the other hand can be harder to pinpoint. They involve IgG or IgM antibodies and can take up to three days to cause a reaction after eating the food. Reactions often include symptoms that are not obviously related to digestion, like headaches, joint pain, and skin issues and can be related to how much was consumed (a little may be fine but a lot may cause issues). An example of this would be a nightshade sensitivity that causes eczema to flare up within 1-3 days of consuming foods like tomatoes, eggplant, or peppers.
I am not a fan of IgG Food Sensitivity Tests because they can give a lot of false positives and are not necessarily correlated with the symptoms of a food sensitivity. Instead, it may be more helpful to implement an anti-inflammatory diet and focus on good gut health. 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 irritate your immune system.
3. Food Intolerances
Food intolerances are not immune-mediated, meaning that they do not involve antibodies. If you have a food intolerance, it’s directly related to your body being unable to digest a specific food. The reaction will occur after you eat the food and only last until the food exits your body. An example of this would be lactose intolerance causing gas, bloating, and diarrhea after drinking milk. This happens because the body doesn’t produce enough of the enzyme lactase.
Another example with a different mechanism is IBS with FODMAP intolerance, where there may be an overgrowth of bacteria in the GI tract fermenting the FODMAPs and causing symptoms like gas, bloating, constipation or diarrhea. Working with a practitioner to address the root cause of the overgrowth and reduce populations of bad bacteria can help you enjoy more of these foods.
What about Celiac Disease?
Celiac Disease is not an allergy, sensitivity, or intolerance. It's an autoimmune disease triggered by gluten, meaning that it causes the body to attack and damage its own tissues. This only occurs when gluten enters the small intestine, so it can be controlled with a 100% gluten-free diet. Like an allergy, even tiny amounts of gluten from cross-contamination can cause damage so it's best to treat Celiac Disease as a true allergy and be extremely careful.
Undiagnosed or poorly managed Celiac Disease can also increase the likelihood that you will develop food sensitivities and intolerances, because the gut becomes so damaged. Over time, as your small intestine heals and you gut lining becomes less permeable, you should be able to enjoy a wider variety of foods.
If you're interested in getting to the root cause of your food reactions so you can relax and enjoy food again, check out my Gut Reset Program. In the program we use functional testing to identify digestive enzyme and microbiome imbalances that could be contributing to food reactions and you will receive a personalized plan to rebalance your gut and optimize digestion.