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Addressing Mold Toxicity: a root cause of diseases and symptoms
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The World Health Organization (WHO) reported that indoor dampness effects upto 50% of the indoor environments in North America predisposing them to the effect of mold. Twenty-five percent of the world's crops are contaminated by mold. Molds are significant source of a wide variety of health problems including digestive issues, allergies and histamine related symptoms, respiratory issues, immune dysfunction, kidney diseases, cancer, chronic fatigue syndrome, neurological symptoms as well as Multiple Chemical Sensitivity. Unfortunately, most of us are unaware of being exposed to mold in our homes, schools, and work environments. This blog provides an overview of how mold toxicity affects our health and how to address it.

How does mold grow indoors?


When excessive moisture interacts with building materials, mold growth occurs.  Molds grow best in warm, damp, and humid conditions. They spread and reproduce by making spores. These spores can survive harsh environmental conditions, such as dry conditions, and will stay dormant until they come in contact with dampness or moisture. Then they start becoming active and produce more spores. Sick building syndrome is a term that refers to acute and chronic symptoms and illnesses that are directly a result of time spent in a building. The complainants may be localized in a particular room or zone or may be widespread throughout the building. Mold toxins are an important cause of this syndrome.


Common mold and mold related toxins


Toxins released by molds are known as mycotoxins and these lead to profound adverse health effects including death in humans and other animal groups in low concentrations. 


What are the health effects of mold?


1. Digestive issues


Mycotoxins have been known to cause adverse effects to the digestive tract. These include


  • Increasing intestinal permeability (Leaky gut)

  • Increase in intestinal permeability lead to transmission of toxic bacteria and bacterial products in the blood stream with adverse outcomes.

  • They change the bacterial flora in the gut

  • They enhance the growth of bad bacteria

  • The interaction of mycotoxin with the gut bacteria leads to the development of liver cancer.


2. Histamine related disorders of the lung and skin


Mold spores in the environment can be inhaled and induces allergic airway diseases such as lung inflammation (Pneumonitis), inflammation of the airways (Asthma),chronic cough, and  inflammation of the nasal cavity and sinuses (post nasal drip, rhinitis, and sinusitis). In addition, they can also cause skin reactions such as rashes, urticaria and fluid retention. It can also cause headaches and eye itching. These symptoms are mediated by mast cells. Mast cells are immune cells that can activate the process of inflammation through the release of histamine and other inflammatory mediators (cytokines). 



3. Immune dysfunction


Macrophages are immune cells which play an important role in our ability to fight infections. Exposure to mold toxins has been found to directly reduce the viability of these immune cells. The decrease was seen immediately after exposure to mold toxin, within 24 hours and continued for a long period of time. The effect was directly correlated to the concentration of the toxin and led to the death of these macrophages. These changes explain the ability of molds to reduce immunity and prevent our bodies' ability to protect us from foreign invaders such as bacteria and viruses.


4. Kidney Disease


Both Citrinin and Ochratoxins have been found to be extremely toxic to kidneys. Experiments with rats showed that even 1 dose of these toxins led to increased urination, leakage of sugar and protein in the urine, reduced ability to concentrate urine, decreased kidney function as well as microscopic structural changes in the kidneys. These changes persisted for days after the exposure. These toxins can also cause destruction of large parts of kidneys leading to kidney failure.


5. Cancer


Two mycotoxins, aflatoxin and sterigmatocystin are known to cause cancers in primates. Many other mycotoxins (aflatoxin, sterigmatocystin, ochratoxin, fumonisin, and zearalenone) have been found to cause mutations, These mutations can be the triggers for initiation of cancer. These toxins damage the DNA of cells leading to abnormal protein formation and or processing leading to organ dysfunction. Aflatoxin is a well known cause of liver cancer, while ochratoxin has been found to cause formation of DNA adducts - a phenomena linked to initiation of cancer. Zearalenone has potent estrogenic activity with the potential for stimulating estrogen-sensitive tumors such as breast and cervical cancers. Zearalenone has been found to cause multiple reproductive issues in exposed animals. There is a link between esophageal cancer and Fumonisin mycotoxins. 


6. Chronic fatigue syndrome


Brewer et al. conducted a research study to investigate the role of mold exposure amongst 112 patients with a prior diagnosis of CFS by assessing the presence of mycotoxins in their urine. Urine was tested for aflatoxins, ochratoxin A and macrocyclic trichothecenes. Almost 93% of patients were positive for at least one mycotoxin. Upto 30% of the cases had more than one mycotoxin in their urine. Ochratoxin A was the most prevalent mycotoxin detected in 83%, followed by tricothenes found in 44% of cases. Over 90% of patients had  a history of current and/or past exposure to water damaged buildings. Environmental testing of the water damaged buildings indicated by a subset of these patients revealed the presence of these molds and mycotoxins. No mycotoxins were found in the urine samples of the healthy control population with no history of exposure to a moldy environment.


7. Neurological symptoms


Individuals exposed to mycotoxins experience a wide variety of neurological and psychiatric symptoms including pain syndromes, movement disorders, delirium, dementia, and disorders of balance and coordination. In one study, patients exposed to mold had a variety of cognitive impairments,in the areas of verbal learning, visuospatial learning and memory, and psychomotor speed. Patients also had emotional dysfunction including depression, anxiety, lack of concentration, brain fog and sleep disorders .


Children exposed to mold toxins were found to have low IQ, neurodevelopment and behavioral abnormalities. Mycotoxins have also been strongly associated with autism spectrum disorder and the mechanism of action is an increase in the permeability of blood brain barrier, allowing penetration of toxins, leading to inflammation and disruption of neuronal connections. Mycotoxins Aflatoxin M1, ochratoxin A, and fumonisin B1 were found to be significantly higher in the urine of children with autism. Ochratoxin reduces the function of mitochondria (an important structure in the nerve cell responsible for energy production) and causes the destruction of neurons (nerve  cells).


8. Multiple Chemical Sensitivity


Multiple Chemical Sensitivity (MCS) is a condition when a person experiences a complex array of recurrent non-specific symptoms attributable to low dose of chemicals that are well tolerated by most people. There is no single-specific diagnostic laboratory test to diagnose this condition although many inflammatory markers may be elevated in individuals suffering from MCS. A Finish study clearly demonstrated a direct connection between exposure to indoor mold toxins and MCS. The study concluded that toxic molds cause severe morbidity and mortality in adults and children, even domestic pets. A relatively short stay in a damaged building is a potential hazard to health and life. Individuals exposed to Mycotoxins develop a cluster of autoimmune diseases such as thyroid disorders, Sjogren's disease etc. and cancers at an alarmingly high rate compared to those not exposed. 


A Functional Approach to indoor Mold toxicity


A functional approach requires a thorough history to identify and connect potential exposure and Mycotoxins associated with the outcome.


  1. Identify the Mycotoxins in the urine

  2. Avoid exposure ASAP

  3. Remove everything that could be contaminated with mold spores.

  4. Follow the protocol for removing mold toxins as prescribed by your functional physician. It is important that you work closely with a physician with an expertise in the area.








  5. Bennett JW, Klich M. Mycotoxins. Clin Microbiol Rev. 2003;16(3):497–516. doi:10.1128/cmr.16.3.497-516.2003.

  6. Kumar P, Mahato DK, Kamle M, Mohanta TK, Kang SG. Aflatoxins: A Global Concern for Food Safety, Human Health and Their Management. Front Microbiol. 2017;7:2170. Published 2017 Jan 17. doi:10.3389/fmicb.2016.02170.!po=3.26087












  18. Kuhn DM, Ghannoum MA. Indoor mold, toxigenic fungi, and Stachybotrys chartarum: infectious disease perspective. Clin Microbiol Rev. 2003;16(1):144–172. doi:10.1128/cmr.16.1.144-172.2003

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