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Mold Genes: How Do Mycotoxins Affect You?

We are all exposed to mold on a daily basis. Fungi are essential to life: they dwell on our skin, make our soil fertile, and help decompose organic matter. However… some molds give off microscopic toxins that can harm you.

For some people, exposure to specific types of mold can result in long-term health problems.

This article explores the research on mold toxins and how these molecules affect our health. I’ll explain the genetic variants involved in the body’s detoxification process before concluding with what clinical trials reveal about supplements and lifestyle changes for mold toxicity recovery.  Members will see their genotype report below, plus additional solutions in the Lifehacks section. Join today

How can mold harm your health?

Molds are everywhere! From the green fuzz on an old loaf of bread to the essential fungi found throughout healthy soil, mold is a general term for the types of fungi that are filamentous. Yeast are also classified as fungi, but they are single-celled and don’t produce filaments.

Exposure to certain types of mold – the kind that produce mycotoxins – can cause chronic health-related problems, gut health issues, immediate injury, or even death.

What are mycotoxins?

Mycotoxins are microscopic mold metabolites that can cause harm. They are naturally occurring toxins produced by filamentous fungi (molds). They are classified as toxins because even at very low doses, they can cause ill effects or even death in humans and other animals.[ref]

They differ from the toxins found in poisonous mushrooms (which are the fruiting bodies of fungi). Instead, mycotoxins are found in trace amounts on moldy nuts, grains, coffee, and dried fruits. Molds growing on damp building materials can also produce mycotoxins.

Aflatoxins, ochratoxins, trichothecenes, zearalenone, fumonisins, and ergotamine are more commonly studied mycotoxins, but more than 300 mycotoxins are known to exist. Some of these mycotoxins are produced by more than one type of fungus, while others are specific to a single fungal species.[ref]

The World Health Organization estimates that up to 25% of crops are contaminated at some point with mold or fungal growth.[ref] Many human food processing methods, though, reduce mold or mycotoxin contamination.

How are we exposed to mycotoxins?

Mycotoxins are produced by fungi that grow on crops, in preserved foods, and in the soil. It’s a problem in areas with warm and humid conditions favorable for fungal growth.

The main routes of exposure to mycotoxins include:[ref]

  • ingestion (most common route of exposure)
  • inhalation
  • via the skin (dermal)

Food can be contaminated by mycotoxins either in the field or during drying and processing. In general, good quality control with harvesting, drying, and processing food prevents the formation of mycotoxins.

In other words, every ear of corn or coffee bean you consume isn’t going to be contaminated with mycotoxins. Instead, contamination with mycotoxins is more of a problem when agricultural processes and food handling procedures are poor.[ref]

Mycotoxins pose a two-fold problem: they are toxic at extremely low levels and are chemically stable, allowing them to survive food processing and cooking.[ref]

Specific mycotoxins:

Ochratoxin A is produced by Aspergillus and Penicillium species of mold. Ochratoxin A is toxic and likely carcinogenic, especially in the kidneys and liver.[ref]

Ochratoxin A is found in cereals, coffee, wine, dried fruits, beer, and grape juice. It also occurs in animal organs (kidneys, liver) of grain-fed animals. In humans, ochratoxin A can have a severe immunosuppressant effect at low and high exposure doses.[ref] Ochratoxin A also changes the absorption of nutrients in the intestines.[ref]

Zearalenone is produced by Fusarium species. It can bind to estrogen receptors (mimic estrogen) and is a reproductive toxin in animal studies. Additionally, zearalenone is toxic to the liver and leads to cell death.[ref]

One study describes zearalenone as: “It is a non-steroidal compound that exhibits oestrogen-like activity in certain farm animals such as cattle, sheep and pigs.”[ref]

Aflatoxins are produced by a couple of different Aspergillus species. There are multiple types of aflatoxins, with aflatoxin B1 being one of the most toxic and carcinogenic.

Aflatoxins are often found in peanut products and in milk from cows fed with contaminated grain. Aflatoxin B1 is also found in cottonseed oil.[ref]

“Aflatoxicosis is a toxic hepatitis leading to jaundice and, in severe cases, death.”[ref]

Chronic dietary exposure to aflatoxins is linked to liver cancer.[ref]

Fumonisins are metabolites produced by Fusarium species. Certain fumonisin subtypes are linked to an increased risk of esophageal cancer, and in general, fumonisins are considered a WHO class 2B carcinogen.[ref]

An interesting observation by researchers is that fumonisins interact with folate uptake in cells: “Because fumonisin B1 reduces uptake of folate in different cell lines, fumonisin consumption has been implicated in neural tube defects in human babies”.[ref]

Trichothecene mycotoxins encompass about 100 subtypes of metabolites from Fusarium species. Trichothecenes can contaminate corn, wheat, barley, oats, rice, rye, vegetables, and other crops. They are a common cause of poisoning in animals eating contaminated feed. Trichothecenes are easily absorbed and then distributed throughout the animal’s tissues. Human exposure comes from consuming meat, milk, and eggs from animals fed contaminated grains.[ref]

Consumption of trichothecene-contaminated foods can cause gastrointestinal issues. This mycotoxin affects actively dividing cells, such as in the intestinal or oral mucosa, and causes cell death.[ref]

Ergot alkaloids are compounds created by Claviceps species, which are fungal pathogens that attack grasses such as rye. Ergot poisoning has been known for centuries. It was described as a “slow nervous fever” that occurred in the summer after a wet winter in the Middle Ages. Modern grain processing methods eliminate ergot as a problem in human food sources, but it can still affect animals that graze on grasses or contaminated grains.[ref]

St. Anthony’s fire refers to an illness caused by consuming ergot-contaminated grain (usually rye). The symptoms recorded throughout history include convulsions, sores, hallucinations or mania, headaches, nausea, gangrene, and burning extremities.[ref] The gangrene occurs because ergot is a vasoconstrictor, and too much constriction cuts off blood circulation to the extremities. The neuroactive components in the ergot alkaloids are similar to precursor molecules for LSD. Interestingly, a couple of Parkinson’s drugs are derived from ergot.

Deoxynivalenol is a mycotoxin produced by Fusarium species. It is found on wheat, beans, and some spices. Deoxynivalenol causes severe gastrointestinal issues when consumed via contaminated foods.[ref]

What happens when you are exposed to mycotoxins?

Exposure to mycotoxins can produce various responses, depending on the toxin, exposure route, amount, and individual genetic differences.

Lung inflammation, mitochondrial function: An inflammatory response occurs when lung tissue is exposed to airborne trichothecenes. Il-1B increases in a manner dependent on NLRP3 activation. This mycotoxin can impair mitochondrial function and inhibit the synthesis of certain proteins.[ref]

Organ damage: From airborne exposure, the mycotoxins can travel to the liver, kidneys, and spleen. It causes inflammatory cytokines to increase in all of these organs. Specifically, researchers found higher levels of IL-1B, IL-6, and TNF-alpha.[ref]

Another mycotoxin that increases inflammation in the lungs is aflatoxin G1. It increases not only inflammatory cytokines but also induces specific detoxification genes.[ref]

Genetic variants can influence how strong the inflammatory response may be. For example, TNF-alpha variants may cause some individuals to produce more of this cytokine in response to a stimulus.

Read more about inflammatory genetic variants.

It is not as simple, though, as mycotoxin = inflammation.

Suppressed immune response: Zearalenone is a mycotoxin that suppresses the normal inflammatory response that cells should produce against pathogenic bacteria. Zearalenone exposure tamps down the proinflammatory cytokines (TNF-alpha, IL1B, IL6) that should be produced in response to gram-negative bacteria. This ‘tamping down’ suggests a reduction in the innate immune response, which could leave someone vulnerable to infections after exposure to zearalenone.[ref]

Kidney damage: Oral exposure to ochratoxin A from contaminated food is linked to kidney injury. Animal studies show that ochratoxin A increases inflammatory cytokines and up-regulates genes related to fibrosis in the kidneys. Blocking NLRP3, an inflammatory activator, was able to suppress the kidney injury.[ref]

Gut microbiome interaction: Exposure to mycotoxins through foods can impact the gut microbiome in several ways. First, some gut microbes can metabolize mycotoxins – sometimes creating more toxic metabolites. Mycotoxins can also impact the composition of the gut microbiome. Interestingly, certain mycotoxins affect the way nutrients are absorbed.[ref]

Types of mold exposure:

Exposure to mycotoxins can be either acute or chronic:

  • Acute exposure will bring quick and severe poisoning symptoms for someone exposed to higher levels of mycotoxins at one time (e.g., eating a bunch of moldy nuts).
  • Chronic exposure is more common. Very low-dose exposure over long periods can result in various health consequences, including an increased risk of certain cancers.

Acute exposure by consuming foods containing mycotoxins can cause food poisoning type symptoms. Researchers think that a percentage of food poisoning cases each year are actually due to mycotoxins.

Mycotoxins often contaminate coffee beans and tea leaves at low levels. Drinking contaminated coffee or tea every morning is one way we can be chronically exposed to trace levels of mycotoxins.[ref]

In addition to being consumed in foods, mycotoxins can be airborne and enter your lungs when you breathe. Some mycotoxins can also enter through your skin.

Detoxifying mycotoxins:

We are all regularly exposed to mycotoxins at trace levels, and our bodies have ways of getting rid of mycotoxins. The key is to not overwhelm the detoxification system through either an excess of toxins or by not having enough of the cofactors needed for detoxification.

Let’s look at some examples of the pathways involved in mycotoxin elimination:

Aflatoxin can be combined in the body with glutathione, making it easy for the body to excrete. Having enough glutathione available to handle mycotoxins is essential, and the GST family of genes is important here.[ref]

Ochratoxin A increases oxidative stress. It can be counteracted on a cellular level by the Nrf2 pathway, which is necessary for upregulating genes that combat reactive oxygen species.[ref]

Glucuronidation is a phase II detoxification process by which a glucaric acid molecule is added to a toxin to make it more easily excreted and less reactive. Zearalenone mycotoxins are excreted via the glucuronidation pathway, specifically utilizing UGT1A1, UGT1A3, and UGT1A8.[ref]

Additionally, methylation, hydroxylation (addition of a hydroxyl group), hydrolysis, and sulfation reactions are utilized for transforming mycotoxins for excretion from the body.[ref]

My take-away: Knowing the specific mycotoxin involved is important for understanding which detoxification pathway to target.

“Mold Genes” — are the HLA types in 23andMe?

One question that I get asked fairly often is how to find the mold genes in 23andMe data… There is a lot of confusion and over-simplification being promoted on the internet about “mold genes”.

In general, some natural health websites write about mold genes and refer to certain HLA types. Practitioners identified these HLA types more than a decade ago as being likely to have mold reactions. Listed symptoms of mold illness include fatigue, muscle pain, headaches, sinus problems, vision problems, brain fog, mood swings, vertigo, joint pain, weakness, and more.

I’m going, to be honest here… I can’t find any quality research studies on this. There are research-backed links between asthma and mold sensitivity in children[ref], but asthma isn’t one of the ‘mold symptoms’ being talked about in alternative circles. There are thousands of research studies on the poisoning-type symptoms from mycotoxins. But the multitude of mold illness symptoms and common HLA types doesn’t have much in the way of published research.

Does a lack of peer-reviewed research mean that people don’t really have mold illness or mold toxicity? Of course not. Clinicians make valid discoveries about health all the time, and not everything is written in a peer-reviewed journal.

But, I am not a clinician, and thus I’m sticking with just explaining what high-quality research studies show us, which, in this case, is not a lot.

Could mold symptoms be related to mycotoxin exposure? Quite possibly. Instead of being able to tell you if you have ‘the mold gene’, I would rather invite you to read about the different ways your genetic variants impact your ability to handle mycotoxins.

Mycotoxin Reaction Genotype Report:

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Lifehacks for mycotoxins: Supplements, lifestyle changes, environmental factors

The big picture with mycotoxins is avoidance and counteracting the effects of exposure.

Avoiding contamination:

Food sources of mycotoxins:
Pigs that eat foods contaminated with ochratoxin A are a continuing dietary source of ochratoxin for people who regularly eat pork products.[ref] Many countries do periodic testing for contamination, so this isn’t a problem with all pork. But this is a reason to choose high-quality pork or pork from a known local farmer when possible.

In general, food production and storage are important in avoiding mold contamination, especially in humid climates. Coffee is frequently a source of mycotoxin contaminants.[ref][ref] Peanuts, especially in tropical regions, are a source of aflatoxin exposure.[ref][ref]

Check your environment:

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Why join Genetic Lifehacks?

~ Membership supports Genetic Lifehack's goal of explaining the latest health and genetics research.
~ It gives you access to the full article, including the Genotype and Lifehacks sections.
~ You'll see your genetic data in the articles and reports.

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About the Author:
Debbie Moon is the founder of Genetic Lifehacks. Fascinated by the connections between genes, diet, and health, her goal is to help you understand how to apply genetics to your diet and lifestyle decisions. Debbie has a BS in engineering from Colorado School of Mines and an MSc in biological sciences from Clemson University. Debbie combines an engineering mindset with a biological systems approach to help you understand how genetic differences impact your optimal health.