Risk of Eating Moldy Bread

Eating moldy bread or other foods can be dangerous.
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Eating moldy bread or other foods can be dangerous. You could be ingesting mycotoxins, or fungal poisons, according to Michigan State University. Some types of mold can cause food poisoning, which can make you ill and result in stomach cramps, fever, diarrhea, vomiting and nausea.

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Types of Bread Mold

There is no guarantee that only one particular chain or type of mold grows on bread. Jackson Kung'u, a microbiologist from the Mycological Society of America, notes multiple cases where humans have eaten moldy bread and either became ill or died from doing so.

Depending on the type of mold growing on the bread, it could contain gangrenous ergotisms, alimentary toxic aleukia, Stachybotrys chartarum or aflatoxicosis. These are just a few examples of the types of bacteria or fungi that can grow on bread.


Of course, this does not mean that every mold is harmful. Penicillium camembertii and Penicillium roquefortii, fusarium venenatum, aspergillus oryzae and other types of mold are used as food cultures for some foods, such as cheeses, and are harmless.

How the Mold Spreads

By the time you see mold on the bread, the mold isn't just isolated to the area that you can visibly see. Kung'u says that bread is porous and by the time you see mold on your bread, it is highly likely that the entire piece, or loaf, is contaminated with the mold. There has to be a high number of mold spores present for mold to be visible. Mold tends to grow in warm, dark areas or where the area has a lot of moisture.


Avoid Food Poisoning

Depending on the type of mold growing on the bread, you may develop food poisoning or a dangerous food-borne disease. Some of these food-borne illnesses, such as salmonella, can be treated and cured, while others, such as Stachybotrys chartarum, can cause irritation of your mouth, nose and throat and lead to shock, hemorrhage, dermal necrosis and death.

See a doctor if you have blood in your vomit or stool, diarrhea that lasts for more than three days, a fever higher than 100.4 F, dehydration (decreased urination, severe weakness, dizziness, excessive thirst) or neurological symptoms, including tingling or blurry vision, as recommended by the Mayo Clinic.


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Store Your Bread Safely

According to the New Mexico State University, College of Agricultural, Consumer and Environmental Sciences, bread should be stored in the pantry or other cool, dry area for three to five days. Once it is opened, store it in an airtight container.

If you freeze your bread, it can last for two to three months. However, homemade bread might not last as long — it does not contain the preservatives found in commercially prepared breads that extend their shelf-life.

Avoid eating any foods that pose a potential risk or threat to your health. Avoid eating foods that appear to have mold on them or are older than their expiration dates. While not all mold is harmful, it's better not to take the chance.