Food Reactivity

Ever head the term food intolerance, food allergies and wondered what they mean or what the difference is?

Food can impact us both positively and negatively. Our choices on what we eat determines which way it falls. How could food cause a reaction and digestive stress? Or our body being reactive to food?

Food Intolerances

Most people are familiar with the food intolerance to lactose. Lactose being the sugar found in mammalian milk. Where you need the enzyme lactase in order to break down the disaccharide into a monosaccharide and then into a single subunit so it can be absorbed through the enterocytes in the gut.

So if you are not able to break it down into this single subunit/ digestible form you are doing to get malabsorption issues. What happens then is your gut bacteria end up feeding on it in this partially digested form and you get a lot of gas, bloating, GI distress and discomfort. This process is not immunologically mediated.

Another good example of an intolerance is to fructose. Some people have problems breaking fructose down into the single monosaccharides so that you can absorb it, so you get digestive distress.

These problems come back to gut health. A lot of people find that when they have certain digestive enzymes they will feel better as they are able to cleave these food particles into smaller pieces and constituents, thus enabling them to absorb food better and that reduces their symptomology.

Food Allergies

This is completely differently to food intolerances, as an inflammatory response is involved. This process involves an immune mediated reaction and are often referred to as “type 1 hypersensitivities”. This involves IgE immune mediated response. IgE is an immunoglobulin that is responding to an “antigen” that is typically always a protein antigen in the food. This is a quick response- and occurs quite fast i.e. within minutes.

For example peanut allergies, when people have a reaction to peanuts they are reacting to the protein in the peanut. When the IgE is released there is a Th2 dominant response (T helper cells which are apart of our immune system). When we test for allergies we test for IgE typically, to see your reactivity.

Th2 cause mast cell degranulation, brain fog,hives, swelling, sneezing, itching etc. If really bad it causes anaphylaxis where the throat can swell it can be difficult to breath and is life threatening.

Food Hypersensitivity

When you eat a certain food repetitively every day and you don’t keep your system upright you can develop food sensitivity. Food sensitivities are considered a delayed “type 4 hypersensitivity” response. Where IgG (another immunoglobulin) gets involved. When you eat that food you get a Th1 response, where you are reacting to the protein in that food (antigen).

Th1 cause inflammatory cytokines released, which cause disruption of tight junctions in the brain and gut to become “leaky” and more permeable. This “leakiness” causes inflammation and the immune response to continue. This is what causes a lot of the symptoms, especially if these foods are inflammatory. This type of reaction is a lot more common than the immediate “allergy” type.

If you want to get tested you need a IgG (4) test to look for your sensitivities to certain foods. Because the trouble with these delayed hypersensitivity reactions is that 24-72hrs after you eat these foods you get a response, hence its called delayed. This can make it hard to determine what exactly it is you are reacting to. Where as in allergies it is immediate- so pretty easy comparatively to figure out what the trigger is.

So you might be thinking, I’m reacting to gluten at the moment and I’m pretty sure its a hypersensitivity. Will i ever be able to eat gluten containing foods again? Gluten sensitivity is a discussion al to itself, as it is quite inflammatory. The short answer for this blog however is yes, for some people, you may be able to eat these foods again.

The key is healing the gut and increasing what is called Treg. Treg helps us have tolerance to these foods. We need to reduce the Th1 response and increase the Treg, we need to reduce that chronic systemic inflammation and seal that gut so its not “leaky” anymore. In time the inflammation will dampen and as the food can’t pass through the gut wall, you may then find that you stop reacting/ having a Th1 response.

Quick note on Celiac

is different to a gluten hypersensitivity. Celiac disease is a IgA and and IgG immune mediated response to the gluten peptide which is a protein that is found in wheat barely and Rye. If you have celiac you also have develop autoantigens to transglutaminase 2. So it is a immune mediated response where your immune system attacks your microvilli in the small intestine- which leads to malabsortopin, bloating and fatigue etc. as you are not able to break down and absorb a lot of the food you are consuming.

The microvilli give the intestine a rough surface like carpet, able to absorb and suck things up. Where as when they are attacked in celiac disease it ends up being flat almost like a hardwood floor, where things just sit and don’t soak in .

In addition there is a increased Th1/Th17 response that leads to more leaky gut and brain as there is this exaggerated inflammatory response.

Having a leaky gut is a prerequisite to all autoimmune disease.

So if you have an autoimmune condition you WILL have some sort of leaky gut. Its a matter of looking at and finding what is triggering and making yours leaky.

Think of the blanket there as the microvilli- all bumpy and the smooth table as when it has been flattened in celiac disease.

Think of the blanket there as the microvilli- all bumpy and the smooth table as when it has been flattened in celiac disease.

Short comments on FODMAPS

Fermentable oligo, di monosaccharides and polyols. These are things such as fructose, articuflca sweetness, sugar alcohols, lactose, fructans etc. found in a lot of fruits and vegetables. That create a lot of gas and bloating, GIT distress because there is some sort of gut dysbiosis/imbalance such as SIBO (small intestinal bowel overgrowth). When we have this imbalance the bacteria feed on these fermentable fibres that these bacteria then feed on that they normally wouldn’t get to, as they should be in the colon not all the way up in the small intestine.


I’ll explore these topics in more detail in future posts. Hope this helps you understand the different types of reactions you can be having to food! xo Courtney











Courtney Dixon