Mold and its Effect on Thyroid Health
The thyroid is a butterfly-shaped gland in the lower front of the neck that produces hormones that regulate many body functions, including metabolism, heart function, digestion, muscle control, brain development, mood regulation, and bone maintenance. It is an important part of your endocrine system, and it is vital to your overall function and wellness.
What does mold have to do with the thyroid?
So what is the connection between mold and the thyroid? As we’ve been discussing, mold is a powerful, but often overlooked, stress on the body and can dysregulate the immune system, especially if one is genetically susceptible to mold. When the immune system and gastrointestinal system are stressed from pathogens (like mold), this can lead to autoimmune conditions, like AITD.
Photo by Lucija Ros on Unsplash
One of the clues we have that mold might play a role in someone’s thyroid health is when someone’s health begins to fall apart after a move. In a 2015 survey of 2232 people who had Hashimoto’s, 20% reported that their health declined after a move (1), possibly indicating a new mold exposure or other environmental toxin exposure. Additionally, we know that if a person is immunosuppressed, we need to be on the lookout for toxic mold. Aspergillus, a mold commonly found in food and in the indoor environment, is a threat to thyroid health, especially of those who are immunosuppressed. Approximately 20% of those with aspergillosis, a condition where the Aspergillus mold infects the body’s tissue, have Aspergillus infiltrating their thyroid (1,2).
What we have seen in our practice:
Clinically, the patients we see who have had mold exposure almost always have thyroid conditions. This may include AITD, hypothyroidism, or non-thyroidal illness syndrome (NTIS), which is also known as Euthyroid Sick Syndrome (ESS).
Autoimmune Thyroid Disease (AITD)
Autoimmune thyroid disease includes Hashimoto’s and Graves’ Disease. In our practice, we consider those with thyroid antibodies above lab range (or even close to lab range) to have AITD. These people are very sensitive to mold exposure and often have significant mold exposure. A significant mold exposure could mean regularly being exposed to mold (home, workplace) or even small exposures over long periods of time. On ultrasound imaging, they present with an enlarged thyroid gland, with heterogenous (diverse, abnormal) edges.
Hypothyroidism and Subclinical Hypothyroidism
Hypothyroidism is the most common effect we see after mold exposure. Hypothyroidism does NOT have thyroid antibodies present, but it does have low thyroid hormone. In functional nutrition, we look at thyroid hormones using functional ranges (optimal lab ranges for thyroid function). They are typically tighter ranges for thyroid markers, and they vary depending on the person’s age and sex. Patients that fall within this category are considered to have subclinical hypothyroidism.
Non-Thyroidal Illness Syndrome (NTIS)/Euthyroid Sick Syndrome (ESS)
NTIS is defined as abnormal thyroid lab findings that are actually normal in illness. It can also be described as “‘normal’ thyroid function found in sick patients.” (3)
Our thyroid gland produces both T4 (Thyroxine) and T3 (Triiodothyronine) based on the stimulus it receives from the pituitary hormone TSH. Most of the hormone released is T4, with a very small portion being T3. Because T4 is INACTIVE, T4 must be converted to T3 as it circulates through the body. T3 is the ACTIVE form of the hormone. When we are ill, Reverse T3 (RT3) increases and less T3 is made from T4. This happens with the common cold or flu, but can happen for longer periods of time in chronic illness.
Patients who have NTIS tend to have low T3 (active form of thyroid) and high reverse T3 (RT3), which is an inactive form of T3 that the body is unable to use. RT3 tends to be high with mold exposure (as it is with infections, blood sugar issues, and stress). As the mycotoxins are reduced in the body as well as the mold exposure, RT3 decreases, which allows more of the hormone to go into the active T3 form.
People who are inflamed or ill, which includes those who are affected by mold, DO NOT convert T4 to T3 well. Because of this, if they are only given a T4 medication, they often do not do well, even if their blood work looks better on paper. T4 influences TSH, so when T4 increases through medication, TSH will often drop, which may inaccurately lead a physician to believe that their thyroid health is improved. Instead, they only have improved T4 hormone, which is the inactive form and unable to be used by the body.
Instead of only giving T4 medication, mold-exposed thyroid patients can benefit from a combination of both T4 and T3 medication, while also working to reduce their mycotoxin levels and reducing mold exposure.
What are some mechanisms that allow mold exposure to lead to thyroid disease?
In our second article in the mold series, we looked at how mold causes immune system dysregulation, creating a condition known as CIRS (Chronic Inflammatory Response Syndrome). Here are some specific mechanisms by which mold exposure can lead to thyroid disease:
Low MSH and leaky gut
One of the things that mold exposure can lead to is low MSH production. MSH stands for melanocyte stimulating hormone. Low levels of this hormone can lead to a widening of the tight junctions in the intestines, which increases intestinal permeability. This is also referred to as leaky gut. Leaky gut can lead to autoimmune conditions, such as Hashimoto’s or Graves’ disease. It’s also important to note that having low MSH can also lead to staph bacteria colonizing in the deep nasal passages. This condition is known as MARCoNS. This infection releases toxins that exacerbate the inflammatory cycle (4).
Increased production of TGF Beta-1
Another mechanism of CIRS that may lead to a thyroid autoimmune condition is the increased production of the cytokine, TGF (transforming growth factor) Beta-1. As TGF Beta-1 increases, regulatory T cells decrease. Regulatory T cells play a big role in keeping autoimmune disease at bay, and if a person has a low number of these important cells, they become more susceptible to developing an autoimmune condition like AITD (4).
Increased sensitivity of the immune system
As we’ve discussed in our mold series, mycotoxins that are released from molds are actually neurotoxins. These toxins are able to pass through the blood-brain barrier and disrupt neurological function. This can also allow the opportunity for new allergies and sensitivities to occur, which further taxes the immune system. The increase in stress of the immune system and body gives space for autoimmune conditions to occur (5).
Is the thyroid sensitive to other toxins?
The thyroid tends to be sensitive to compounds that are “disruptive” to healthy endocrine function. This includes mold but also includes various chemicals and toxins (6,7). Examples of these chemicals/toxins include pesticides, bisphenol- A (BPA), phthalates, and flame retardants, to name a few. Regarding pesticides, organochlorine (OC) pesticides tend to have a structure that resembles those of T3 and T4. Therefore, they may mimic the activity of thyroid hormones, which leads to thyroid dysfunction. With BPA and phthalates, research has found that high urinary concentrations of these compounds lead to altered levels of T3, T4, and TSH. Emerging evidence shows that flame retardants have also had altering effects on thyroid hormone levels and function (8).
As noted, mold is also a thyroid disruptor, which can destroy this vital gland. Additionally, those who already have a thyroid condition may be more sensitive to a mold exposure.
We specialize in working with patients who have had mold exposure and those living with thyroid conditions. If you suspect that mold may be affecting your thyroid or other function, please give us a call.
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