Common Fungus Among Us
The genus Fusarium is common in soil, marine and river environments as well as on plants all over the world. F. species are some of the most problematic molds known in the northern temperate regions of the world. They are responsible for many plant diseases and they can produce potent mycotoxins. Fusarium is pink-white in color and is more commonly associated with the mycotoxins zearalenone, deoxynivalenol, T-2 toxin and fumonisins.
Where Fusarium Is Found
Fusarium mycotoxins are commonly found on grains. Besides ingestion, fusarium mycotoxins can also gain access to the body by inhalation. The most important Fusarium food mycotoxins are the families of trichothecenes, and fumonisins.
Nasty Mycotoxins Fusarium Is Known To Produce
Fusarium species produce fumonisins, and Trichothecenes .
The trichothecenes are a large family of chemically related toxins and include
- T-2 toxinT-2,
- HT-2 toxin (HT-2),
- Deoxynivalenol (DON),
- Diacetoxyscirpenol (DAS),
- Fusarenone-X (FUS-X),
- Nivalenol (NIV),
- Diacetylnivalenol (DAS),
- Zearalenone (ZEN)
The black mold Stachybotrys chartarum is also known to produce trichothecenes such as Satratoxin-G (SG).
These trichothecene mycotoxins of the Fusarium species are generally of two types:
- Nonestrogenic trichothecenes such as
ZEN is a nonsteroidal, estrogenic mycotoxin and has been shown to be able to bind competitively to estrogen receptors.
Fusarium Toxins In Food
Fusarium toxin production in food largely depends on environmental conditions, such as temperature and humidity. This means fusarium toxin contamination can not be avoided completely. Therefore, exposure to these toxins are a permanent health risk for both humans and farm animals.
Two Notable Fusarium, Tricothecene Mycotoxins Found In Food
- Deoxynivalenol (DON) - also called vomitoxin
- Zearalenone (ZEN)
These two mycotoxins are common contaminants of grains given to farm animals, and for some people in their food supply. They largely grow on the grains prior to harvest. There are regulatory limits on the amounts of both of these mycotoxins allowed in food by many countries.
Deoxynivalenol has been shown to inhibit protein synthesis and modulate the immune responce. It can cause acute effects of nausea, vomitting and diarrhea in humans. Chronic effects are not well known. In animals chronic ingestion has been shown to cause anorexia, growth retardation, immunotoxicity, reproductive impairment, and impaired fetal development. On a pathophysiological level, problems with neuroendocrine signaling, induction of proinflammatory genes, altered gut integrity and growth hormone axis disruption is seen.
In humans DON is thought to be primarily excreted in the urine. In the UK it has been determined that about 72% of DON is excreted in the urine and in a study I read with one person who ingested DON, he excreted 68% in his urine. Not a big study but how many people are willing to consume food knowingly contaminated with DON? I would guess that 72% is about right. As this one person was at 60% the first day and then up to 71% the second three days. DON urinary metabolites disappeared 21.5 hours after the last dietary exposure. The most highly contaminated urine samples showed up 3-5 hours after the contaminated meal. The glucuronidation rate was 76% which is similar to UK results in prior research. Glurucronidation is used to conjugate and remove it from the body.
Zearalenone is thought to be one of the most hazardous natural endocrine disruptors in our environment. It has been shown to produce reproductive disorders in animals and humans.
Zearalenone has a more complex metabolism than does DON. It has a variety of degradation and conjugation products. In a study of one person ingesting ZEN about 10% of it was excreted in urine 3-10 hours after eating. I am in the process of writing up a full page article on this mycotoxin.