Food Allergies vs. Food Intolerances

Food allergies and intolerances have become  increasingly prevalent! However, they are actually not to be confused with each other as one is quite different from the other. In today’s post, we are discussing the difference between food intolerances and allergies, signs and symptoms of each, plus their underlying causes, common food intolerances and allergies, as well as how to approach food intolerances. 

What’s the difference between a food allergy and intolerance? 

Food allergies and intolerances may be easily confused because they both cause problematic symptoms after ingestion. However, the mechanisms and often severity between the two are very different!

Food allergies arise due to an immune system reaction in response to a protein found within a food. This reaction may be categorized as an allergen-specific immunoglobulin E antibody (IgE) or a non-IgE mediated food allergy. 

To keep things simple, IgE-mediated food allergies are the most common and the most dangerous as the reaction is quick, due to an antibody (a protein that serves as the alert system in response to an invader – in this case, the proteins found in specific foods) that  floats around in the bloodstream. Symptoms will often include hives, shortness of breath, cough, wheezing, stomach cramping, vomiting, weak pulse, swelling of the lips or tongue, and in severe cases, anaphylaxis. 

On the other hand, non-IgE mediated food allergies still involve the immune system but do not involve IgE antibodies. While the exact mechanisms are unclear, this type of allergy often presents as GI-related symptoms. Typically this includes stomach pain, diarrhea, vomiting, and extreme bloating. Notably, non-IgE mediated food allergies symptoms present later than IgE-mediated, usually occurring a few hours later and up to three days later. 

In contrast, food intolerances are not a result of the immune system at all. Rather, they are usually due to an underlying cause (we’ll get into this later) and often manifest as GI symptoms but can also cause more systematic symptoms. It’s important to recognize that while these symptoms are bothersome and uncomfortable, they are not life-threatening in comparison to true food allergies. 

An example of this is lactose intolerance, where one’s body does not produce enough lactase  –  a digestive enzyme to breakdown lactose (the protein found in milk). The result is digestive distress, often diarrhea, abdominal cramping, bloating and reflux. 

Signs and symptoms of food intolerances

Common symptoms of food intolerances are thought to be related to digestion. However, we recognize that symptoms of food intolerance may go beyond the GI tract affecting all parts of the body. 

Common signs and symptoms of food intolerances:

• Bloating and gas
• Nausea 
• Constipation/diarrhea
• Fatigue 
• Brain fog 
• Irritability and anxiety 
• Headaches
• Skin reactions (acne, rash, eczema) 
• Sleep disturbances
• Inflammation 
• Joint and muscle pain 

For example, I have found that some clients who eat gluten feel fine initially, but then the next couple of days suffer from constipation, fatigue, and brain fog. In times like these, food intolerances easily go unnoticed because the symptoms are not isolated to the GI tract and do not occur immediately after consumption. 

Underlying causes for food intolerances

Food intolerances can develop at any point in life due to a number of reasons. Typically, food intolerances stem from imbalances in the gut and overload of  inflammation throughout the body.

Common underlying causes of food intolerances:

• Gut infections and parasites
• Small intestine bacterial overgrowth (SIBO)
• Gut hyperpermeability/ leaky gut
• Digestive Enzyme insufficiency (ex. Lactase in lactose intolerance)
• Histamine Intolerance 
• Celiac Disease (if undiagnosed)
• Sensitivity to food additives (ex. sulfites)
• Genetics 
• Environmental factors (ex. mold)

In rare cases (but not unheard of), some of these root causes have been the reason behind a food allergy, not intolerance! Yes, you read that correctly. I  had personal experience with this where I developed a food allergy to nuts causing anaphylaxis out of the blue when I had never had any problems with nuts before. It turns out, I had a parasite that was driving this immune response. Once I got rid of the parasite and healed my gut, I was able to slowly reintroduce nuts back into my diet without an allergic reaction! 

If something feels off to you health-wise, always work with a health professional to get a closer look at what’s going on! 

How to approach food intolerances

Getting to the bottom of your food intolerances is a bit of a lengthy process, but definitely well worth it. Outlined below are some steps to identifying and working with your food intolerances. 

1. Stop eating all triggering foods for about four weeks (if you’re  not sure what these are keep a food diary and log all foods and symptoms)
2. Pay attention to how your body feels (think: digestion, energy, joint pain, etc)
3. Reintroduce one food at a time in small amounts (ex: 1/4 avocado on it’s own)
4. Monitor symptoms (helps to write it out!)
5. If you experience no reactions (great!), then repeat steps 3-4 with another food (if you have multiple)
6. If you’re still sensitive to the food, keep removing from your diet for now and give your body a bit more time to heal!

Note that if you’re having sensitivities to a bunch of different foods then there’s likely a reason for it! We encourage you to work with a health professional like us to help get to the bottom of it! 

Common food sensitivities 

If you’re not sure where to begin. We’ve compiled a list of foods that are commonly  poorly tolerated, so that you can be more mindful of your symptoms when you eat them. 

Common foods that are poorly tolerated:

• Pit fruits (apricots, peaches, avocados- not that in small amounts ~ ¼ cup they’re usually fine)
• Furry fruits (raspberries, strawberries)
• Dairy (milk, butter, cheese)
• Gluten (breads, pastas, pizzas) 
• Peppers 
• Tomatoes

Bottom Line

Food allergies and intolerances are a pain! Luckily, in most cases food intolerances don’t have to be a forever thing. Everybody’s body is different, but when we address the root cause, decrease inflammation, and heal the gut our bodies can drastically change and begin to tolerate foods that were once problematic. 

Suffering from food allergies or intolerances? Click here to work with us!