Most consumers are unaware of the exposure to
toxic molds infested in their homes, office or schools. But most of the time,
these microorganisms are difficult to detect because their development is not
visible macroscopically and their detection requires a specific mycological
analysis. Unfortunately, some types of mold
can cause damage to the human body, and their toxicity is not limited to
their multiplication, indeed they are alsotoxic indirectly through the mycotoxins they produce.
Unfortunately, often underestimated by home
owners, the harm caused by these mycotoxins to the human body is diverse and
can range from acute intoxication to
chronic fatigue. It can also cause allergic reactions or an increased predisposition
to certain cancers.
So, what are these mycotoxins? What are their
types and how do they damage our health? How can we detect them? And above all,
how can we protect ourselves from them?
What are Mycotoxins?
According to the World Health Organization, mycotoxins are toxic compounds naturally
produced by certain types of molds (fungi).They grow on either
on the floor or walls in a humid and confined environment or on some foods.
Mold growth can occur before or after harvest, during storage, on or in the
food itself, often in a hot, humid and
Mycotoxins are produced by just over 360 species of mold, mostly belonging to the
type of Aspergillus, Fusarium and Penicillium. They have a low molecular weight
and are most often thermo-stable in non-aqueous medium, and therefore difficult
to degrade. In most cases, they can
survive in food even after the elimination of mold.
There are several hundred types of mycotoxins, but the most harmful ones for our health are Aflatoxins, Ochratoxin A, Patulin, Fumonisins, Zearalenone and Nivalenol. They appear in the food chain because of the contamination of crops by molds, these toxins can also contaminate the human being by air. Even if they are mostly known for long term harmful effects, such as immune deficiency or cancer, mycotoxins can also expose to immediate complications such as acute intoxication.
Means of contamination:Mycotoxins have two ways of contamination:
Digestive contamination: (through food)
In 1985, the Food and Agriculture Organization of the United Nations (FAO) estimated that 25% of the world’s vegetable, fruit and grain crops were affected by mycotoxins, which reduced food, both plant and animal, available worldwide.
Aerial contamination: (through air)
Aerial contamination is just as important as the previous one. Indeed, mold contained in the environment increases the development of diffuse interstitial lung diseases, Parkinson as well as other neurodegenerative diseases.
It should be noted that mycotoxins are not volatile, in this mode of contamination, they adsorb to dust and can enter the body by inhalation of aerosols
Mycotoxins in the environment, like Stachybotrys chartarum, are frequently involved in the sick building syndrome. In these cases, after a definitive move, the clinical, radiological and functional parameters of the patients are most often normalized.
Effects of mycotoxins on the body:
Mycotoxins are generally thermo-stable and do not get destroyed by the usual processes of cooking and sterilization. Some of them have very high acute toxicity (single exposure at high dose), however, this type of exposure is exceptional in humans and concerns most often animals. In human, repeated exposure to low or very low doses (chronic effects) is very common. Indeed, these toxins can be present in our food for years and often accumulate in our bodies.
One of the mycotoxins modes of action is the increase in tartaric acid production which, by competing with malic acid in the Krebs cycle, decreases the production of ATP (the main source of energy of our cells). This can lead to various hepatotoxic, neurotoxic, nephrotoxic, mutagenic, teratogenic, carcinogenic and immunosuppressive effects.
All these effects combine to cause a state of lethargy often referred to as the Chronic Fatigue Syndrome (CFS). This chronicity is often related to the fact that mycotoxins and especially OTA accumulates in the body and have a very long elimination half-life.
Here is a list of symptoms related to the Chronic Fatigue Syndrome (CFS) that is often caused by these agents:
- Irritation, burning, redness, itchy eyes.
- Congestion or bleeding of the nose.
- Irritation, burning sensation of the throat.
- Sneezing, dry cough.
- Abnormal shortness of breath.
- Slight elevation of the body temperature.
- Unusual headaches, sometimes resistant to analgesics.
- Eruption (redness, pimples, patches), skin irritation.
- Nervousness, unexplained irritability.
- Memory and concentration problems.
- Lethargy, continuous fatigue.
- Insomnia, diurnal sleepiness.
- Unexplained muscle pain decreased physical ability.
- Decreased cognitive performances.
Beside the CFS, mycotoxins’ exposure can have acute complications like kidney or hepatic failure. It can also have teratogenic effects on the fetus in pregnant women. A prolonged exposure to mycotoxins (for many years) also increases the risk of some types of cancer like the lung carcinoma.
In any case of suspicion of any mycotoxins contamination, do not hesitate to test their presence in the urine and consult your doctor.
Mycotoxins detection :
Mycotoxins are found in the mycelium and spores but especially spread after the destruction of the fungus responsible for their production. This is why these molecules are called “secondary” (As they are not directly necessary for the life of the mushroom). They are thermo stable and often active at very low doses. They are also resistant to biological treatments and moderate heat (eg cooking).
The main mycotoxins that we look for in usual tests are:
- Aflatoxin in Aspergillus,
- Ochratoxin A in Penicillium and Aspergillus,
- Fusarium toxins (fumonisins, zearalenone, trichothecenes etc.),
- The toxin of Alternaria (alternariol),
Regarding the detection methods of mycotoxins, immunochemical one are the most used.
They are based on the use of antitoxin antibodies, they allow rapid detection of mycotoxins in large numbers and types of samples (such as urine). One of the most reliable methods uses an enzyme marker of antibodies and is called “Enzyme Linked Immuno Sorbent Assay (ELISA)”.
During this test, the toxin must bind to a number of antibody binding sites in the extraction solution, immobilized in a plate, resulting in signal quenching; in other words, the less signal emits, the more toxin is present.
It should be noted that the direct detection of mycotoxins is more significant than the detection of molds –usual mycological analysis), because the mycotoxins are generally more resistant than molds.
Prevention and decontamination :
Prevention of mycotoxins’ contamination of raw materials may involve the use of fungicides that inhibit mold growth. To this are added the following methods:
- Physical methods: washing, drying, grinding, manual or mechanized sorting of contaminated foodstuffs, mechanical separation of the shell and the skin which are the essential place of contamination, treatment by thermal shock. Ventilation in contaminated confined environments, anti-mold paint …
methods: As the ammonia or
methods: Such as the addition
of mold inhibitor (propionate) or the dilution (amalgam or mixture) of
contaminated grain with non-contaminated grain for animal feed.
Some of these practices increase the risks, and of course should be avoided. But, in the current state of scientific and technical knowledge and despite improvements in production and storage techniques, science hasn’t found out how to completely prevent the development of mold. It is likely that it will not be possible without employing means with more negative side effects, especially in ecological terms, but also in terms of health.
It is not possible to eliminate mycotoxins in food preparation without altering the nutritional value of products, and it is often difficult to decontaminate the environment we live in.
As a result, the presence of mycotoxins in food and environment cannot be totally eliminated. This presence is also highly dependent on factors we can’t control like climatic conditions.