Food Intolerance vs. Food Sensitivity vs. Food Allergy: What's the Difference?
If you've ever done a food sensitivity panel and felt more confused walking out than walking in, you're not alone.
Most people use the terms food allergy, food sensitivity, and food intolerance interchangeably. They're actually three very different things, and understanding the difference might change everything about how you approach food and your health.
Food allergies
A true food allergy is an immediate immune response. Think peanuts and anaphylaxis. The reaction is fast, often dramatic, and mediated by a specific antibody called IgE. These are the allergies that show up on a standard allergy test and are generally well understood by conventional medicine.
Food sensitivities
Food sensitivities are also immune mediated, but the response is slower and more variable. This is what most functional medicine panels test for, looking at IgG antibodies to a wide range of foods and allergens. The problem is that these results change constantly depending on what you've eaten recently, how stressed you've been, the state of your gut, and a dozen other factors.
A mentor of mine once sent the same blood sample to a lab labeled as two different patients and got two different results. That tells you everything you need to know about how reliable these panels are as a long term guide. They can be useful as a snapshot, but they're not the foundation I want to build a treatment plan on.
Food intolerances
A true food intolerance is different entirely. It isn't about the immune system. It's about your genetics.
Your genes code for enzymes. Enzymes are what allow your body to break down and absorb nutrients from food. When you lack the enzyme needed to digest a particular food, your body can't convert it into usable nutrition. Instead, bacterial digestion of that food creates inflammatory byproducts that create a toxic burden in your system over time.
This is what the Carroll Food Intolerance Method identifies. And unlike sensitivities, it doesn't change. Your genetics are your genetics.
What makes Carroll different
The Carroll Method has been around for over 100 years. It was developed as a constitutional assessment tool, meaning it looks at you as a whole rather than testing a panel of common allergens. Everyone has at least one food intolerance. Most people have one or two primary foods and often a combination of two foods that must be separated in the diet.
Here's what surprises most people: the intolerances aren't always what you'd expect. They don't follow botanical food families or common sense groupings. Dairy intolerance, for example, extends far beyond obvious dairy products into hidden sources in supplements, medications, and even some non-dairy alternatives. The same is true for potato, fruit, sugar, egg, and other categories. The depth of what's hidden in each category is something most people have never considered.
And you can't just supplement your way around a true intolerance. If your body lacks the enzyme, taking more of that food or adding digestive support doesn't solve the underlying problem.
The patient who changed everything for me
I had a patient with chronic idiopathic urticaria. Hives of unknown origin. He had spent thousands of dollars seeing allergists, trying steroids, and eventually starting experimental monthly injections, all while managing a host of other chronic symptoms. Nothing was getting to the root of it.
As a last resort, I asked a colleague to run his Carroll assessment. Within four days of complete elimination of his intolerant foods, I received a message that he was 80% hive free.
That was the moment I knew I had to take this method seriously and get trained myself.
Where to start
If you've been chasing symptoms for years, tried elimination diets without lasting results, or done sensitivity panels that left you more confused than before, a Carroll Food Intolerance assessment might be the piece you've been missing.
It's one of the first things I offer new patients, and it's included in all of my packages because I believe it's that foundational.
If you'd like to learn more or book an assessment, I'd love to connect.
