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Can the mould in blue cheese be as harmful as mould in the house?

Uncategorized Oct 30, 2020

When we see mould on our food our immediate reaction is to throw it away. To us, it is an indication that the food has turned bad, and we assume that food would not taste the same because fermentation has started. Along with this, we begin to question the texture, aroma and appearance of the food.

However, we sometimes see mould as a delicious component of some of our favourite indulgences.

Mould is, of course, responsible for the speckles within blue cheese and it’s characteristic saltiness and sharpness. It is caused by the cultivation of Penicillium roqueforti and Penicillium glaucum during the oxygenation of the cheese.

Mould can be seriously harmful to us, especially to those who suffer from an allergy to it, so is there a heightened risk from eating blue cheese?

We know that allergies and immune responses are influenced by our environmental exposures in our early life. In fact, eating cheese at 18 months of age shows a protective effect especially for eczema and food allergies. This is because our bodies develop an immune response to the cultures within the cheese which it carries on into later life.

So, what causes the body to react to an allergy?

There are two immune defence mechanisms, triggered by immunoglobulin reactions termed IgG and IgE. 

We all have IgG antibodies, and most food intolerances are caused by IgG. The reaction itself occurs sometime after ingesting the foodstuff, and reactions are often inflammatory. Over time, our bodies can sometimes overcome the allergy response or reduce its intensity.

IgE, on the other hand, is more severe. They usually exist for a person’s entire life and symptoms often appear within seconds. They may include severe swelling, breathing difficulties, rashes, itching, and in severe cases and anaphylactic shock. 

But can blue cheese trigger a severe allergic response?

There are reported cases of people suffering from sinusitis to the blue cheese fungus. Interestingly there are case studies of workers in cheese factories showing a hypersensitivity pneumonitis reaction, suggesting that their increased exposure results in a heightened immune response.

The moulds within blue cheese are forms of Penicillin, which is a common allergen. In the United Kingdom, 2.7 million people report or self-report a penicillin allergy. However, this is incorrect in up to 95% of cases. Furthermore, there is a shortage of trained allergists, resulting in confusion as to whether or not a person’s allergy is an IgG or IgE reaction. This results in misdiagnoses, which has further complications in the prescription of antibiotics.

Nevertheless, a true allergy to penicillin can result in a rash in over 50% of people, with 7% experience blistering skin or peeling. Additionally, 8% have difficulty breathing, 20% have a swelling reaction and 18% feel sick. Only 5% have the most serious and harmful anaphylaxis response.

So, is a reaction to mould growing in the house the same as a reaction to blue cheese?

IgG sensitivity to Aspergillus fumigatus, or mould that can be found growing in the house or on food, is different from IgE sensitivity to penicillin. 

So, if you feel that the mould in your house caused by damp or flooding is causing your body to have an adverse reaction, then it’s unlikely that he blue cheese in your fridge is going to cause you harm. The allergies are caused by different moulds, and so you’d be very unlucky to be affected by both. Even so, it’s more likely that you’ll have an IgG reaction, rather than the more harmful IgE.

However, if you have been diagnosed with an IgE reaction to penicillin, then it is plausible that the penicillin growths within blue cheese could cause you harm.

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