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Mycotoxins & Neurotoxicity Series

Mycotoxins and Neurotoxicity Part 2: When Mycotoxins Reach the Brain

January 31, 2023

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Explore The Series

Part 1

Part 2

Part 3

Part 4

When Mycotoxins Reach the Brain

There is some debate on how and when mycotoxins reach the brain.  The two most common pathways are: 1) via penetrating Blood Brain Barrier (“BBB”) 2) Directly through inhalation via sinus tissue.  The BBB is a physiological barrier that separates the brain and the cerebrospinal fluid in the central nervous system from the circulating blood. It is composed of tight junctions between the endothelial cells that line the blood vessels in the brain, which prevent the passage of many molecules, ions, and cells from the bloodstream into the brain tissue.

When Mycotoxins Reach the Brain-Blood Brain Barrier

Mycotoxins are secondary metabolites produced by molds.  They are potent chemical or gaseos neurotoxins that must reach the brain to cause the headaches, cognitive issues, motor function impairment, and psychological symptoms associated with mold sensitivity.  These symptoms are amongst the most concerning to patients and contribute to debilitating symptoms that can prevent wellness and greatly reduce productivity at work and in the home. The home contains many toxic chemicals used to manufacture construction materials and add flame retardants.  Moisture issues such as water damage from leaks or flooding will cause mycotoxin producing molds to reproduce on these materials when exposed to moisture. Because symptoms of mold toxicity mimic other chronic diseases, a precise diagnosis is often elusive and takes time.  Read “The Toxic Mold Mystery” HERE.

Additional symptoms:

  • Dizziness
  • Brain fog
  • Memory issues-forgetfulness
  • Motor dysfunction
  • Sensitivity to light

Mycotoxin Exposure Sources

Mycotoxins enter our bodies via dermal exposure, digestion, ocular or other membrane exposure, and inhalation. Detoxification efforts require many bodily systems to protect, expel, metabolize, and excrete toxic elements.  These systems are efficient; but, they are not fully capable of protecting the body from all toxic elements.

Mycotoxin producing molds also infiltrate food supplies.  Unfortunately, several common molds reproduce when moisture reaches grains production.  Mold is ubiquitous throughout the world.  Controlling moisture is key to preventing amplified growth. Moisture is often determined by weather. Add a result, food sources are regularly exposed to moisture where mold can reproduce.  Common bulk foods where mycotoxins have been found include nuts, peanut butter, coffee, and improperly dried teas and spices.

Mycotoxins Are Neurotoxins

Compared with the amount of research on digestive, urinary, immune, and reproduction systems, there are few reports of the effects of mycotoxins in brain tissues. One particular article published in 2011 provided a comprehensive look at mycotoxins that are known neurotoxins and their impact on rodent brains. The article focused on four mycotoxins known to induce neurotoxicity in rodents, including T-2 toxin, macrocyclic trichothecenes, fumonisin B(1) (FB(1)) and ochratochin A (OTA).  While these are just a small number of mycotoxins, the comprehensive investigation of these neurotoxins on rodent brain tissue provides evidence of the toxic effects on the brain. 

There are several mycotoxins that are known to be neurotoxins, including:

  • Aflatoxins: produced by the fungi Aspergillus flavus and Aspergillus parasiticus, which can contaminate crops such as peanuts, corn, and wheat. Aflatoxins have been linked to a number of health problems, including liver cancer and neurological damage.
  • Ochratoxins: produced by the fungi Aspergillus ochraceus and Penicillium viridicatum, which can contaminate crops such as grains, coffee, and wine. Ochratoxins have been linked to kidney damage and neurological effects.
  • Ergot alkaloids: produced by the fungus Claviceps purpurea, which can infect cereal crops such as rye and wheat. Ergot alkaloids have been linked to a number of neurological effects, including hallucinations and convulsions.
  • Trichothecenes: produced by various species of Fusarium, which can infect a wide range of crops including cereals, corn, and peanuts. Trichothecenes have been linked to a variety of health effects, including neurological effects and suppression of the immune system.

It is important to note that mycotoxins can be found in many types of food and feed products, and that they can cause serious health problems when ingested in large amounts. 

Brain Toxicity Due to Inhalation

Scientific studies relating the effects of inhaling mycotoxins on the brain are limited.   It is commonly understood and accepted that inhalation of toxins and pollutants produce health effects.

The following image identifies the BBB, the position of sinuses in relation to the BBS, and demonstrates the potential impact of mycotoxin poisoning because of inhaling mycotoxins.

When Mycotoxins Reach the Brain-Neurotoxicity in brain due to mold inhalation

Inhalation of dangerous substances can cause toxicity in humans and animals. The toxicity caused by inhalation can depend on the specific substance, the concentration, and the duration of exposure.

These Substances Include:

  • Carbon monoxide (CO): This colorless, odorless gas is produced by burning fossil fuels and can be found in the exhaust of vehicles and other combustion sources. Inhaling high concentrations of CO can cause headaches, dizziness, confusion, nausea, and in severe cases, unconsciousness and death.
  • Nitrogen oxides (NOx): These gases are produced by burning fossil fuels and can be found in vehicle exhaust and industrial emissions. Inhaling high concentrations of NOx can cause respiratory irritation, bronchoconstriction, and increased risk of respiratory infections.
  • Volatile organic compounds (VOCs): These are a large group of chemicals that can be found in many products such as paints, cleaning supplies, and building materials. Inhaling high concentrations of VOCs can cause irritation of the eyes, nose, and throat, as well as headaches, dizziness, and nausea.
  • Particulate Matter (PM): This is a mixture of solid particles and liquid droplets found in the air, which can come from various sources such as forest fires, construction sites and human activities. Inhaling high concentrations of PM can cause respiratory and cardiovascular problems.
  • Asbestos: asbestos is a naturally occurring mineral that was widely used in construction materials, and inhaling asbestos fibers can cause lung cancer, mesothelioma, and asbestosis.

It’s important to note that some people may be more sensitive to the effects of inhaled toxins than others, such as people with pre-existing respiratory conditions. To minimize the risk of toxicity from inhalation, it is important to avoid exposure to known toxins, use personal protective equipment and to properly ventilate indoor spaces.

Current Scientific Literature 

There have been some scientific communities that suggest mycotoxicosis cannot occur from inhalation of mold spores.  One publication modeled possibilities of high doses of mycotoxins that could be inhaled during a continuous exposure to mold spores.  These molds were reported to contain toxic concentration of mycotoxins. These scientists calculated doses and came to a blanket conclusion that inhalation of mycotoxins is not likely possible in sufficient amounts to cause health effects.  This suggests that there is a lack of association between mold exposure and mycotoxicosis in indoor environments. This paper further suggests that cases of human mycotoxicosis is implausible following inhalation exposure to mycotoxins in mold-contaminated home, school, or office environments.

Practical Evidence on Mycotoxin Paths to the Brain

I have discussed these issues with building scientists and Indoor Air Quality specialists.  It is generally believed that mycotoxicosis is primarily caused by inhalation of mycotoxins due to water damaged homes.  The cause-and-effect evidence from customers over decades of their professional careers clearly explains how patients get better when homes are remediated and IAQ is clean.

When Mycotoxins Reach the Brain-Sources of Indoor Pollution

In addition to chemical pollutants causing harm, it is common for Ear Nose and Throat Physicians to encounter abundant microbial colonies, “fungal balls”, in the sinuses that must be removed.  These patients often exhibit neurotoxicity adverse effects that correct themselves when the fungal ball(s) have been surgically removed and sinuses are properly remediated and medicated using antifungal medicines.

Jack Thrasher Ph.D. Providing Evidence of Mycotoxins Reaching the Brain

Dr. Jack Thrasher (1938-2017), a well-known immunotoxicologist, was a trailblazer in the field of environmental toxicology.  His toxicology and immunotoxicology work regarding ground water contamination, indoor air issues, smog, solvents, pesticides, implantable devices and many different chemicals and chemical compounds had made Dr. Thrasher renowned in his field. He became a thought leader and published numerous publications surrounding environmental illness including groundbreaking research around mycotoxicosis and multiple chemical sensitivity.

Dr. Thrasher worked with ENT physicians to access tissue removed from sinuses to be tested for mycotoxins.  His publications “Surgical and Medical Management of Sinus Mucosal and Systemic Mycotoxicosis” demonstrated that tissues removed from fungal sinusitis patients tested positive for mycotoxins.  Neurological symptoms were specifically addressed.  His collaboration further confirmed that maximum detoxification therapy would help these neurotoxicity patients.

Dr. Thrasher worked with numerous physicians investigating the presence of fungi from chronic sinusitis patients.  However, positive results from urine testing were inconclusive with cohorts delivering positive results in as few as 22% of patients with mycotoxins present in sinus tissues.  His various publications address the toxic potential of mycotoxin fragments, mycotoxin presence in biofilm contributing to the chronic nature of Chronic Rhinosinusitis (CRS), and the fact that mycotoxin poisoning can be present in patient for several years.


  1. Doi, Kunio et. al. “Mechanisms of Mycotoxin-Induced Neurotoxicity through Oxidative Stress-Associated Pathways.” International Journal of Molecular Science. August 15, 2011
  2. Carnahan, Jill. MD.  “Mycotoxins and Your Brain: How Invisible Fungus Can Cause Brain Fog and More”  October, 9, 2017.
  3. Bruce J Kelman et. al. “Risk from inhaled mycotoxins in indoor office and residential environments.” 2004 Jan-Feb;23(1):3-10 
  4. Dennis Thrasher J.  “Surgical and Medical Management of Sinus Mucosal and Systemic Mycotoxicosis” J Oto Res Sur.  Jan. 2017.
  5. Joseph H. Brewer *, Jack D. Thrasher “Chronic Illness Associated with Mold and Mycotoxins: Is Naso-Sinus Fungal Biofilm the Culprit?” Toxins 2014, 6, 66-80

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