One of the visitors to our website sent us these questions/observations. “Eating moldy bread is discouraged. Where can I find the facts that prove this? Are there molds that grow on bread that are harmless? Some of my patients that survived food shortages in The UK during World War II by eating moldy bread and other foods insist that such fears about mold are unfounded”.

My comments/answers are that eating mouldy food is risky. The reason is that one cannot tell which moulds or even bacteria are growing on such food. While some moulds or even bacteria may not harm the person who eats this kind of food, some other moulds and bacteria are known to produce very toxic metabolites. However, even the toxin producers require certain conditions to produce the toxins. Also, some people are more resistant to mould poisoning than others. Recently, over 100 people died in one of the African countries after consuming grains (maize) contaminated by Aspergillus flavus, a mould that produces aflatoxin.

To conclude, not all moulds are dangerous. In fact a number of moulds are used in food processing or processed as food. Eating food contaminated by toxin producing moulds such as Aspergillus spp and Penicillium spp is dangerous. Since we cannot tell (without testing) whether the food is contaminated with a toxin producing mould and whether the mould has secreted toxins into the food, it is safe to treat such food as dangerous.


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