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Intolerances and allergies

Registered nutritional therapist Michaella Mazzoni takes a look at the differences between food intolerances and allergies

Allergies and intolerances are two different things. However, they do share some symptoms. In our immune system, we have different immune cells that each take care of different things. In the case of allergies and intolerances, we have IgE cells (allergic response) and IgG cells (intolerance).

Food intolerance

A food intolerance response can be mild to severe and can cause symptoms anywhere from 20 minutes to 72 hours from consumption, making them tricky to identify outside of blood testing. Food intolerance symptoms are typically digestive, such as constipation/diarrhoea (which can, in some cases, be misdiagnosed as IBS), nausea, bloating and vomiting. However, there are some symptoms of a food intolerance which I often see in my clinic that people do not think to attribute to an intolerance, such as headaches, fatigue, spots, swelling around the eyes, feeling groggy and unmotivated. Often, by identifying and removing the right foods, these symptoms are alleviated.

A big factor in how food intolerances are developed is gut integrity. Imagine a mesh net: this is what lines the inside of your gut. In an optimal environment, this net has high ‘integrity’, meaning nothing gets in or out that shouldn’t. However, in many people this net can start to lose its integrity and this is called increased intestinal permeability, or ‘leaky gut.’ In this case, undigested proteins from foods can pass through into the bloodstream, where they shouldn’t be, thus causing an immune response, otherwise known as a food intolerance. This is why when I do testing in my clinic, the results that come back are often the foods the client eats the most. Removing these foods, working on the gut integrity and then reintroducing the food is how I support food intolerances and is a big difference to allergies, which should not be reintroduced/kept in the diet once identified.

Common food intolerances


An allergic response is much quicker than an intolerance and symptoms are more severe. This is where we would experience an anaphylaxis reaction, such as skin rashing, swelling of the lips/throat, throat closing, wheezing and/or difficulty breathing. An allergy is life threatening.

Common allergens

The most accurate way to test for a food intolerance and/or allergy is with a registered practitioner. This is so you have the best chance of getting accurate information from a reputable laboratory (I use Lorisian/York Test) and am able to utilise the information in the safest way possible. For example, I have had clients who, upon finding out they had food intolerances from an online test, have avoided a big list of foods, without addressing the issue of the gut lining health and, in the end, developed nutrient deficiencies and more food intolerances. Interestingly, in some cases the intolerances detected are less about the food itself and more about the lack of digestive enzymes to break them down. Again, a registered practitioner should be able to identify this for you.

For diagnosing allergies, a skin test and/or pin prick blood test can be done. You may be able to get this sort of testing through your GP.

I see food intolerances more and more in my clinic, from small children to adults in their sixties. The key takeaways are working on your gut health, supporting your digestive enzymes with bitter foods and citrus (lemon and water, apple cider vinegar and water) and working alongside a registered practitioner to help you identify your intolerance/allergy and give you a plan to move forward.

Michaella Mazzoni, Registered NT, DipCNM mBANT CNHC reg, offers private nutrition consultations to help support all areas of health. She works at Napier’s/D.Atkinson, Neal’s Yard and Soma and offers video consultations for those unable to travel to clinic. To book an appointment, email Michaella at info@michaellamazzoninutrition or call 07786 841 333.

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