7 hidden causes for thyroid dysfunction
Lots of people experience hypothyroid symptoms when they are dealing with a chronic illness whether they have Hashimoto’s, autoimmune hypothyroidism or not.
That usually happens because many things influence thyroid function, such as the hormones leptin, cortisol, estrogen, and micronutrients such as selenium, iodine, B12, iron, zinc, and vitamin D.
But that's not all, many other things influence your thyroid function.
Let's find out 7 hidden causes for Thyroid dysfunction
1- Dietary components⠀
Suboptimal quality & poor nutrient density foods we consume and the ability of the body to digest the food to absorb the necessary vitamins and minerals needed for thyroid function. There is also exposure to chronic immune irritants in consuming food additives/preservatives aka “fraken-foods” as they can disrupt thyroid function.
Long term dietary caloric restriction, yoyo dieting can impair the function of the pituitary gland. The pituitary gland is where numerous endocrine hormones are produced:
Adrenocorticotrophic hormone (ACTH)
Thyroid-stimulating hormone (TSH)
Luteinising hormone (LH)
Follicle-stimulating hormone (FSH)
Growth hormone (GH)
Melanocyte-stimulating hormone (MSH)
The thyroid is responsible for the metabolic rate of the body, if the body perceives a chronic negative energy balance, it will lower the metabolic rate, the body temperature, and limit the extraneous functions of the body such as those hormones related to fertility.
Evolutionarily this was adventageous I suspect; if a society was experiencing famine it would be a suboptimal time to be pregnant as a woman.
Also, super worthy mentioning, even more now that everyone is either fasting or jumping on a keto diet….
If done incorrectly, doing a ketogenic diet or fasting can negatively impact your adrenal function, thyroid function and fertility. When someone is metabolically inflexible, meaning the ability of the body to mobilize stored fat for fuel is impaired eating a diet high in fat and low in carbohydrates, or fasting can be perceived by the body as a significant stressor. This stress depending on on your individual state of health can result in negative consequences should the body be pushed beyond its limits.
If you have a history of thyroid, adrenal, or sex hormone imbalance, I highly recommend working with a trained specialist prior to engaging in one of these types of practices. And if you decide to try the ketogenic diet or fast and end up with the “Keto flu” or “symptoms of hypoglycemia” please know, it’s time to eat some “slow” carbs, such as a sweet potato, those symptoms are your body struggling to utilize ketones to produce energy.
2- Molecular mimicry
Due to molecular mimicry food items when broken down can resemble thyroid hormone and bind to thyroid hormone receptor site.
Common culprits in the susceptible individual include:
Remember this is just a trigger, the other components of autoimmunity must be present as well to create the “perfect storm,” genetic susceptibility & intestinal permeability,
How do infections potentially cause autoimmune thyroid disease?
Molecular mimicry: This is when the infection proteins looks very similar to the thyroid proteins as such the immune system attacks the thyroid as a case of mistaken identity.
Bystander Effect: When the infection resides in the actual thyroid gland the immune system will attack the gland in hopes of destroying the infection.
Leaky gut induced by infections of the gums, sinuses or gut: When an infection induces a disruption of the mucosal lining the tissue in that area become increasingly permeable allow the infection to enter the bloodstream resulting in further immune activation and potential autoimmunity.
Known infectious triggers for Hashimoto’s:
The entire herpes family of virus is believed to be a trigger for autoimmunity, however simplex types 1 & 2 the (oral and genital herpes) and Epstein Barr (the virus causing mono) have been researched the most.
Lyme disease and lyme co-infections such as Borrelia burgdorferi
Chronic streptococcus infections (strep throat)
Chronic bacterial overgrowth of the gut, such as SIBO
Chronic yeast infections in the mouth, nose, ears, vagina, or gut
* This list is not extensive just those currently identified to be more common in those diagnosed with autoimmune thyroid disease.
The body produces the very same chemical response to stress whether it is a physical, emotional or psychological. Chronic elevation in stress hormones such as cortisol impairs the hypothalmic pituitary adrenal axis and thyroid axes, HPA / HPT axis.
In the HPT axis, thyrotropin releasing hormone, TRH is produced in the hypothalamus and it is what stimulates the and thyroid releasing hormone to be produced by the pituitary gland. TSH is then what ultimately stimulates the thyroid to produce active T3 and inactive T4 hormones. The downregulation of these HPA axis causes decreased thyroid receptor sensitivity, creating a negative feedback loop to the hypothalamus telling it to produce less TRH.
HPA axis dysregulation is also more commonly known as adrenal fatigue or adrenal dysfunction, another feature of this dysregulation can be an excess estrogen. Both elevated estrogen from HPA axis dysregulation aka, “cortisol steal” and environmental estrogens can lead to increased binding of thyroid binding globulin, TBG.
The function of TBG is to carry the thyroid hormones hormones thyroxine (T4) and triiodothyronine (T3) in the bloodstream.
Leaving these thyroid hormone “taxi’s” unavailable for transport, and you feeling all the symptoms of hypothyroidism.
5- Excessive exercise
Excessive exercise, can be perceived as another form of “stress” and lead to HPA axis dysfunction and in turn induce hypothyroidism.
The exercise itself can induce elevations in TSH, thereby leading to reduced free T4 &3 overtime if adequate recovery time does not occur.
Excessive exercise can also lead to suboptimal stores of thyroid supportive minerals such as low iodine, selenium, iron, zinc, magnesium and copper, and vitamins such as vitamin A, B’s, C, and D.
There is some evidence that intense exercise in the person who already had hypothyroidism that exercise elevates lactate dehydrogenase & creatine kinase and this population and could even be used as a means to better identify the person with subclinical hypothyroidism.
6- Toxic chemicals⠀
Pollutants in our air, food, water, cleaning and self care products may all potentially impair thyroid function.
It is not an extensive list, just a few examples of those with research backing the increased incidence of thyroid impairment with their elevated levels in those with thyroid disease:
Heavy metals such as lead, mercury, cadmium and aluminum in cooking equipment, water, the pipes in our homes, teeth fillings have all been associated with impaired thyroid function.
Bisphenol-A (BPA) found in household products such as furniture containing flames retardants, dishware and food packaging.
Phthalates, parabens, oxybenzone, “fragrance,” & triclosan found in cleaners, detergent, soaps, lotions, make-up, nail polish
Pesticides and herbicides have been associated with decreased thyroid function such as the organophosphates organochlorines and carbamate pesticides, herbicide paraquat and fungicide benomyl and manebzeb mancozeb.
Chlorine in the air we breathe inside the home (toilet flushing and aerosolization of chlorine in the water to gas) or consumption of chlorine in the water we drink may also play a role in impaired thyroid function.
7- Impaired digestion
A common feature of hypothyroidism is impaired digestion.
Symptoms often include:
Slow gastric emptying
The reasons for these symptoms often include inadequate stomach acid production. Improperly digested food from the stomach entering the intestine may lead to low pancreatic enzyme release and bile production.
The improperly digested food in the intestine leads to mucosal lining disruption, aka “leaky gut.” If food does not move through the intestine at the appropriate rate this can cause overgrowth of non-beneficial bacteria, aka dysbiosis of the microbiome, or gastrointestinal infections.
The rate at which the intestines move is governed by the proper digestion of the food and the stimulation of migratory motor complexes, MMC’s.
MMC’s are triggered by serotonin. The gut is also the sight of the vast majority of serotonin production.
Serotonin’s is produced from amino acids, amino acids come from protein.
When protein is not properly digested the amino acids needed for serotonin production are suboptimal.
Serotonin not only aids mood stability and feeling happy and motivated, but it also plays a critical role in allowing for adequate daily elimination.
Now that you know the 7 hidden causes for thyroid dysfunction, you might be questioning yourself…
“What happens when my TSH and T4 look “fine” but I have ALLLLLL the symptoms of hypothyroidism?”
This is one question I hear in my practice ALLLLLL the time. (and for good reason too!)⠀
To start with: do you have any of the following symptoms or diagnoses?⠀
Long history of yo-yo dieting⠀
Chronic fatigue syndrome⠀
Leptin resistance (blood test)⠀
Autoimmune disease (other than Hashimoto’s)⠀
If so, you may have a cellular hypothyroidism, meaning the conversion of the thyroid hormone into the active form is impaired.⠀
What is central hypothyroidism?
It is hypothyroidism caused by insufficient stimulation by thyroid stimulating hormone (TSH) while having a perfectly normal functioning thyroid gland.
It has an estimated prevalence 1:80,000 to 1:120,000.
It can be secondary hypothyroidism (pituitary) or tertiary hypothyroidism (hypothalamus) in origin.
Traditionally speaking these are RARE conditions caused in children, by things like craniopharyngiomas, previous cranial irradiation for brain tumors or hematologic malignancies. In adults, it is usually due to pituitary macroadenomas, pituitary surgeries or post-irradiation. These conditions are very rare!
Fatigue and peripheral edema are the most common symptoms.
Diagnosis is established by the presence of normal to low-normal TSH, free T3 and T4. The diagnosis is usually confirmed by the thyrotropin releasing hormone stimulation test.
Standard of care after addressing the primary cause is use of levothyroxine to improve symptoms with a goal to keep free T4 in the upper limit of normal reference range.
What isn’t discussed regularly is how central hypothyroidism could be caused by poor cellular concentrations of active thyroid hormone in these tissues.
As a result labs look “fine” and many people suffer from subclinical hypothyroidism.
So why is it that my conventional medical doctor didn’t order a full thyroid panel?⠀
Conventional testing is aimed at deciding if someone is a candidate for thyroid replacement therapy, which typically is T4 only medication (synthroid or levothyroxine) and thus only a TSH and maybe a T4 is performed because treatment will not change by ordering the other tests.⠀
In functional medicine we aim to find the cause of the symptoms and imbalance is function and therefore I recommend testing ( ) indicate the range for optimal function:⠀
TSH (0.5 -2.0 U/mL)
Free T3 (5-7 pmol/L)
Free T4 (15-23 pmol/L)
Reverse T3 (11-18 ng/dL)
TPO antibodies (<2 IU/mL)
TGB antibodies (<2 IU/mL)