top of page

The Difference Between Food Allergies, Intolerances and Sensitivities - part 1 in a 3 part series


I wanted to cry. Life as I knew it was over.


I’d just completed a blood test for food sensitivities. I had been suffering from acne rosacea since my late 30’s that had only gotten progressively worse over the years. My nutritional therapy training directed me to a blood test. I had pursued the standard dermatology route which had only resulted in taking low dose antibiotics, and a waste of time and money on creams, gels, washes, etc. My "gut" told me that there had to be something more to this skin problem than just being a woman, or middle aged. I just couldn't comprehend or swallow taking antibiotics for the rest of my life.

Before the blood draw, I joked with my husband that the test would surely take away all my favorite food groups: coffee, chocolate, cheese, bread, and wine. If only that were the extent of it! The list of foods I couldn’t tolerate was long and complex. The caffeine, alcohol, sugar, dairy and gluten were obvious culprits. But the others mystified me like pumpkin and catfish. I have never eaten catfish in my life.


I dutifully eliminated the foods and was horrified that things got worse before they got better. My acne rosacea flared. I persisted, and once I made it to the other side of the healing reaction, my skin calmed. The pimples disappeared and the redness faded. I was amazed. And my eyes were opened to the power of food and healing. I had proven my dermatologist wrong, and myself right.

Within a few months I was back to eating pretty much normally for me, although I eliminated most processed foods from my diet. The best part: my skin remained clear.


Sound familiar?


Let’s talk about food sensitivities.

What are they? Do they even exist? How do you know if you have them? What do you do about it if you DO have them?

Like so many things in the world of natural health, food sensitivities are hotly debated. For some practitioners, they’re a primary focal point – a key source of systemic inflammation that will exacerbate any other health issue; for others, they simply don’t exist.


So what’s the deal?

Working with food sensitivities was my first experience manipulating diet for health. It was a profound experience, and one that ultimately inspired my decision to pursue functional nutritional therapy as a career.

But years later, as a practitioner, I was frustrated at the tools I had available for identifying and healing food sensitivities. Food sensitivity testing is notoriously unreliable and complex, and helping the body heal from sensitivities without developing new ones is a very delicate matter. If the foods are just eliminated without proper healing work accompanying their removal, a whole new crop of sensitivities will appear, and the list of foods to eliminate just grows and grows. That’s no way to live.

What are food sensitivities?

Food sensitivities are different from allergies, even though the two terms are often used interchangeably. There are actually three types of adverse reaction a body can have to a food:


1. A food allergy

2. A food sensitivity

3. A food intolerance


A food allergy is a very specific type of immune-mediated response to a particular food. It is known as a Type 1 hypersensitivity, or an IgE-mediated hypersensitivity. Essentially, the individual’s immune system reacts adversely to the proteins in a food via a specific antibody pathway. This immune system activation results in the classic “allergy” symptoms: from the minor runny eyes, stuffy nose, and hives, all the way to a full anaphylaxis response that can be life-threatening.

Typically, these are the classic allergies –peanuts, eggs, etc. It’s unusual for someone to have a true food allergy and NOT know it. Most of these are identified by exposure and an extreme response, and subsequently are diagnosed by a medical doctor.


Food sensitivities, on the other hand, come in many different shades of gray. There are multiple mechanisms for a response: some originate in the immune system (what we call an “immune-mediated” response), some happen directly in the cell without direct involvement of the immune system (what we call a “cell-mediated” response).


Regardless of the route it takes in the body, the end result is the release of mediatorshistamines, cytokines, and prostaglandins – that cause inflammation. And this inflammation can affect many different parts of the body at the same time.

Identification of food sensitivities is very complex because of the number of possible mechanisms causing the reaction. Furthermore, the body can express an inflammatory response to a food it consumed immediately, or up to three days later! And of course, there are degrees of inflammation: a food can be highly inflammatory or mildly inflammatory, and a combination of mildly inflammatory foods can cause a big response. This makes it extremely difficult to weed out what foods you’re actually sensitive to.

A food intolerance isn’t about an inflammatory response to a particular food, it’s about our ability to digest it. The most common example of this is lactose intolerance. Our bodies require the enzyme lactase to break down the primary milk sugar, lactose. As infants and through puberty we produce lactase naturally (breast milk contains lactose) but as we age, some people’s production of lactase drops off. These people are what we call “lactose intolerant” because they don’t have the enzymatic ability to break down lactose properly. It’s not an allergy (although dairy allergies of course do exist, but they’re a different mechanism) and it’s not a sensitivity (although again some people do have sensitivities to dairy), it’s an intolerance.

So now you’re probably asking yourself, how do I know if I have food sensitivities? And how do I know if what I’m struggling with is an allergy, a sensitivity, or an intolerance? And does it matter which in terms of how I handle it?

Next week, I’ll tell you how food sensitivities develop, and how to know if you have them.


Stay tuned and if you have a question or comment, don’t hesitate to reach out.



266 views0 comments
bottom of page