The Carnivore Diet and Low Thyroid

Thyroid hormones play a crucial role in managing the body’s metabolic speed, which is why they have become a primary point of discussion among some mainstream wellness influencers and figures regarding nutritional ketosis. 

 

It’s well-documented that transitioning to a diet low in carbohydrates can lead to alterations in thyroid hormone concentrations for certain individuals. So, how exactly would a low-carb diet such as the carnivore diet impact thyroid hormone markers?

 

With significant nuance regarding this topic, let’s explore the relationship between low-carb diets, specifically the carnivore diet, and low thyroid markers, as well as other considerations you’ll need to explore. 

 

Background On the Thyroid

 

 

The thyroid is a small, butterfly-shaped gland located at the front of your neck underneath the skin. It produces and releases hormones and is also a part of your endocrine system. Thyroid hormones are responsible for controlling the speed of your body’s metabolism.  

 

Hormones are vital chemical messengers that play an important role in regulating various bodily functions by transmitting signals through your bloodstream to organs, muscles, and tissues. These chemical signals instruct your body on its operational tasks and timing.

 

Metabolism describes the intricate process through which your body converts the food you eat into the energy needed by every cell to operate effectively.

 

What Is Thyroid Hormone?

 

 

The term “thyroid hormone” encompasses two primary hormones released by your thyroid gland: thyroxine (T4) and triiodothyronine (T3). Although often referred to collectively due to T4’s mostly inactive state—which means it does not directly affect your cells—T3 is the active form that influences your cells and metabolism. Following its release, T4 is converted into T3 by specific organs, enabling it to actively participate in metabolic processes.

 

Additionally, your thyroid secretes a hormone known as calcitonin, which plays a distinct role in managing blood calcium levels by reducing them. Unlike T3 and T4, calcitonin is not considered part of the “thyroid hormone” group and does not influence your metabolic processes.

 

How Are Thyroid Hormone Levels Managed?

 

 

The synthesis and secretion of thyroid hormone—T4 and T3—are governed by a regulatory feedback loop that includes:

 

• Hypothalamus
• Pituitary gland
• Thyroid gland
• Various hormones

 

The hypothalamus, a vital area within your brain, regulates essential bodily functions such as blood pressure, heart rate, body temperature, and digestion.

 

Located just beneath the hypothalamus at the brain’s base, the pituitary gland is a tiny, pea-sized organ that produces and releases eight different hormones.

 

The pituitary gland connects to the hypothalamus via a structure known as the pituitary stalk, composed of blood vessels and nerves. This connection enables the hypothalamus to send signals to the pituitary gland to release specific hormones.

 

The feedback mechanism initiates when the hypothalamus emits thyroid-releasing hormone (TRH), which prompts the pituitary gland to generate and release thyroid-stimulating hormone (TSH). TSH, in turn, stimulates the thyroid gland to produce T4 and T3. Out of the total hormones produced by the thyroid in response to TSH, approximately 80% is T4 and 20% is T3. The thyroid also requires sufficient iodine and tyrosine, obtained from your diet, to synthesize T4 and T3.

 

Iodine is an essential mineral that’s a key component of thyroid hormones. The thyroid gland absorbs iodine from the bloodstream and incorporates it into the T4 and T3 hormones. Each molecule of T4 contains four iodine atoms while T3 contains three iodine atoms.

 

Tyrosine is an amino acid that serves as the foundation for thyroid hormone synthesis. Tyrosine combines with iodine in the thyroid gland to form the precursor molecules that are eventually converted into T4 and T3. 

 

The synthesis process involves several sweets, starting with the uptake of iodine by the thyroid gland, followed by the combination of iodine with tyrosine to form iodothyronine. The iodothyronine is then coupled to produce T4 and T3, which are released into the bloodstream to regulate metabolism and other essential bodily functions.

 

Pro-Tip: The best sources of iodine and tyrosine are animal-based foods. Iodine is abundantly found in seafood, dairy products, eggs, and liver. While seaweed contains the highest source of iodine, its bioavailability can vary drastically based on the species, digestibility, and cooking methods. Tyrosine is one of the 20 amino acids your body requires to make protein—complete protein sources such as meat, poultry, fish, and dairy are ideal.        

 

A feedback loop controls this sequence of hormonal interactions: elevated levels of T3 and T4 inhibit the release of TRH (and consequently TSH). Conversely, when T3 and T4 levels decrease, the feedback loop reactivates. This regulatory system ensures a steady concentration of thyroid hormones in the body.

 

Any disruptions in the functioning of the hypothalamus, pituitary gland, or thyroid can lead to an imbalance in the critical hormones of this system, including T3 and T4.

 

What Is the Role of Thyroid Hormone In the Body?

 

 

Thyroid hormone begins its action once the thyroid gland releases T4 into the bloodstream. In a process known as de-iodination, specific cells in the body convert T4 into T3. T3 is more readily utilized by cells that possess thyroid hormone receptors, making T4 primarily an inactive precursor, while T3 serves as the active form of the hormone.

 

The conversion of T4 to T3 occurs in various tissues and organs, including:

 

• Thyroid 
• Liver
• Kidneys
• Pituitary gland
• Muscles
• Central nervous system
• Brown adipose tissue, which generates heat to regulate body temperature under cold conditions

 

Thyroid hormones, T3 and T4, influence virtually every cell and organ in your body. Their functions include:

 

• Modulating your metabolic rate, which can influence weight loss or gain
• Adjusting your body temperature, either raising or lowering it
• Altering your heart rate, either slowing it down or speeding it up
• Playing a critical role in brain development
• Impacting the rate at which food is digested
• Regulating muscle contractions
• Overseeing skin and bone turnover by managing the rate at which your body renews cells, a natural part of cellular maintenance

 

How Do You Test Thyroid Levels?

 

 

 

There are different laboratory blood tests available to determine thyroid hormone levels and evaluate the functionality of your thyroid. These tests are commonly referred to as thyroid function tests and they consist of:

 

• Total T4 (Thyroxine) test 
• Free T4 (FT4) test
• Total T3 (triiodothyronine) test
• Free T3 (FT3) test
• Thyroid-stimulating hormone (TSH) test

 

Additionally, the following may also be requested as further tests to examine your thyroid health:

 

• Reverse T3 (rT3)
• Thyroid antibodies 
• Thyroglobulin 

 

What Do Thyroid Markers Mean for Testing?

Let’s take a closer look at what these markers mean in terms of testing:

 

Total T4 and Free T4 Test

There are two forms of T4 in your blood: free T4 and bound T4. Free T4 is the active form that enters your tissues when needed. Bound T4 is attached to certain proteins that prevent it from entering your tissues.

 

Total T4 measures both free and bound T4 levels together. A free T4 test will only measure the levels of free T4 in your blood. Free T4 tests are believed to be more accurate compared to total T4 tests for assessing thyroid function.

 

A T4 test is generally used to check how well your thyroid is working as well as diagnosing or monitoring thyroid conditions. 

 

• Low T4: Levels of total and free T4 lower than normal may indicate hypothyroidism (underactive thyroid), thyroiditis (thyroid inflammation), too little iodine in your diet, or side effects from certain drugs. Many variables including certain autoimmune conditions such as Hashimoto disease can cause hypothyroidism. Some symptoms associated with low T4 include:
  • Fatigue
  • Low heart rate
  • Cold intolerance
  • Weight gain
  • Constipation 

 

• High T4: Levels of total and free T4 higher than normal may indicate hyperthyroidism (overactive thyroid), thyroiditis, toxic goiter, toxic thyroid nodule, too much iodine in the diet, pregnancy, or a noncancerous tumor in your pituitary gland. Hyperthyroidism may be a symptom of autoimmune conditions such as Graves’ disease or another chronic condition that causes your thyroid to produce too much T4. Some symptoms associated with high T4 include:
  • Increased bowel movements
  • Irregular or rapid heartbeat
  • Unexplained weight loss
  • Anxiety and irritability 
  • Heat sensitivity      

 

Pro-Tip: Biotin supplementation can cause several thyroid tests to appear abnormal— we recommend stopping all biotin supplementation at least 72 hours before getting labs drawn. Some medications can also impact thyroid markers, making it important to discuss this with your trusted healthcare provider.

 

Total T3 and Free T3 Test

Similar to T4, there are two forms of T3 in your blood: free T3 and bound T3. Free T3 represents approximately 8-10% of circulating T3 in the blood. Total T3 measures both free and bound T3, while free T3 only measures the levels of free T3 in your blood. 

 

The tests for free T3 are generally less accurate than for total T3. T3 testing is usually ordered to help diagnose hyperthyroidism or to monitor T3 levels if you’re taking any thyroid hormone replacement therapy.

 

• Low T3: Levels of total and free T3 lower than normal may indicate hypothyroidism, side effects from certain medications such as steroids, starvation, or severe illness. Many variables including autoimmunity can cause hypothyroidism. Some symptoms associated with low T3 and hypothyroidism include:
  • Fatigue
  • Memory problems
  • Thinning hair
  • Puffy face
  • Weight gain
  • Cold sensitivity
  • Muscle weakness

 

• High T3: Levels of total and free T3 higher than normal may indicate hyperthyroidism, thyroiditis, thyrotoxic periodic paralysis, toxic nodular goiter, and pregnancy. In rarer cases, high T3 may also signify high levels of protein in the blood, thyroid cancer, or thyrotoxicosis. Many variables can cause hyperthyroidism including autoimmunity and certain medical conditions. Some symptoms associated with high T3 and hyperthyroidism include:
  • Twitching or trembling
  • Feeling nervous or anxiety
  • Mood swings
  • Difficulty sleeping
  • Unexplained weight loss
  • Rapid or irregular heartbeat

 

TSH Test

TSH, also referred to as thyrotropin, is a hormone released by the pituitary gland. It triggers your thyroid to produce and release T4 and T3. TSH testing is used to measure how well your thyroid is working. It’s often ordered in tandem with T4 and T3 testing.

 

However, similar to T4 and T3 testing, a TSH test can’t show the root cause of the thyroid problem.  

 

• Low TSH: Low levels of TSH generally indicate that your thyroid gland is making excess thyroid hormone. Since thyroid hormone suppresses TSH release, high levels of thyroid hormone can cause lower-than-normal levels of TSH. In rare cases, issues with the pituitary gland may also cause low TSH levels. Symptoms associated with low TSH and hyperthyroidism include:
  • Heart palpitations
  • Feeling anxious or shaky
  • Diarrhea and more frequent bowel movements
  • Unexplained weight loss with a heightened appetite
  • Irregular periods
  • Swelling of the neck from enlarged thyroid gland

 

• High TSH: High levels of TSH generally indicate that your thyroid isn’t making enough thyroid hormone. Inversely, since thyroid hormone suppresses TSH release, low levels of thyroid hormone can cause the pituitary to make excess TSH. In rare cases, genetic conditions and pituitary gland issues may cause high TSH levels as well. Symptoms associated with high TSH and hypothyroidism include:
  • Tingling and numbness in your hands
  • Fatigue
  • Constipation
  • Depression
  • Unexplained weight gain
  • Decreased libido 
  • Heavy and frequent periods

 

RT3 Test

Reverse T3 (rT3) is an anti-thyroid metabolite that acts to completely block your thyroid from working. As a metabolite of T4, your body can either turn T4 into T3 or rT3 based on what it needs.

 

While this can be a rarer test in the standard care setting, it is an important marker for evaluating thyroid function. We usually include this marker in our thyroid panels for a more holistic view, especially in patients who continue to have thyroid symptoms despite having normal TSH levels. 

 

RT3 is created by your body as a way to manage and control the levels of thyroid hormone your body can use at any time. 

 

This important mediator can unfortunately become hijacked under certain conditions, causing your thyroid to artificially slow down. 

 

RT3 testing illuminates how well your body is using thyroid hormone. 

• Low rT3: If your rT3 levels are low, this often indicates that your body isn’t having any trouble producing the active T3. Having a low rT3 can be a good indicator in certain contexts. 
• High rT3: If your rT3 levels are high, this often means that your body is having trouble converting T4 into the active T3. With high rT3 and high TSH, these elevated markers together can mean that there is a need for more T3 but an issue lies within conversion.     

 

You can read more about interpreting thyroid labs here.

 

Thyroid Antibodies

Thyroid antibody tests measure the level of thyroid antibodies in your blood. This is generally a follow-up test if the thyroid markers above indicate that your thyroid isn’t working properly. Thyroid antibody testing helps determine if an autoimmune condition is causing the issue. 

 

Thyroid antibodies that may be impacting your thyroid function include: 

• Thyroid peroxidase antibodies (TPOAb): High levels can be a sign that Hashimoto’s disease is causing hypothyroidism.
• Thyroglobulin antibodies (TgAb): High levels can be an indicator of Hashimoto’s disease.
• Thyrotropin receptor antibodies (TRAb): Present levels can indicate Graves’ disease.

 

Thyroglobulin

Thyroglobulin testing is a type of tumor marker test used to diagnose thyroiditis (inflammation of the thyroid) and for monitoring thyroid cancer treatment.

 

Now that we’ve covered thyroid function testing, let’s explore how low-carb diets such as the carnivore diet can impact these thyroid markers.

 

What Is the Carnivore Diet?

 

 

The carnivore diet, often called Carnivore or the carnivorous way of eating, involves consuming exclusively animal products and eliminating all plant-based foods and grains. This diet stands apart from ketogenic and other low-carbohydrate diets by offering a genuine zero or near-zero carbohydrate nutritional plan, concentrating mainly on sources of animal protein and fat. 

 

Variants of the carnivore diet exist, each with its own set of rules regarding what foods are allowed or excluded. Gaining knowledge about these different versions enables individuals to choose a diet that not only aligns with their long-term sustainability but also fits their personal health and lifestyle objectives.

 

You can learn more in-depth about the carnivore diet here.

 

The Carnivore Diet and Thyroid Hormone

 

 

Individuals on a carnivore diet often report lower thyroid hormone levels. This seems to be a shared experience among those on a low-carb diet—so, why exactly does this happen? 

 

Various factors can influence thyroid activity. For instance, consuming fewer calories than your body uses, leading to weight loss, can cause a reduction in thyroid function to slow metabolism. This occurs because the body perceives calorie restriction as a potential famine signal, prompting it to decrease metabolic rates by 5-15% to conserve energy. 

 

Additionally, a ketogenic diet such as Carnivore, which is not restricted in calories, can still lead to significantly lower levels of active thyroid hormone in the bloodstream. This reduction occurs even when energy is abundant, and body weight is stable, potentially due to low carbohydrate intake or the presence of ketones affecting levels of circulating active thyroid hormone. 

 

Some interpret the drop in active thyroid hormone (T3) as evidence that carbohydrate limitation hampers thyroid function. Some suggest that carbohydrate intake should not drop below 100 grams per day to avoid this impact. Others recommend taking occasional breaks from low-carb eating to restore thyroid function to standard levels. But how do you account for the hundreds of thousands of people thriving long-term on a low-carb diet? 

 

Why the Carnivore Diet May Cause Low Thyroid Markers

 

 

Another perspective suggests that when stable in weight on a low-carb, high-fat (LCHF) diet such as Carnivore, the body may actually become more responsive to thyroid hormones due to beneficial changes in cell structure and function from being in nutritional ketosis. Consequently, the body may operate efficiently at lower T3 levels. This suggests that a ketogenic diet may enhance thyroid hormone sensitivity, meaning less hormone is needed to achieve the same effects, thereby reducing the strain on the thyroid gland for producing thyroid hormone (T4) and its conversion to T3 in the liver.

 

Specifically reported across Dr. Stephen Phinney and Dr. William Yancy’s clinical studies regarding keto diets, a reduction in free T3 was observed across the approximately 350 individuals enrolled in these various peer-reviewed studies. 

 

Since thyroid hormone requires a holistic view, it’s essential to compare TSH levels because of the negative feedback loop addressed above. If the body senses a reduction in available energy, then it should increase TSH to make more T4 which will eventually make more free T3. However, that was not observed in all these individuals in the clinical keto studies. This is the basis of the argument that the body may be finding a new homeostasis among free T3 levels. 

 

There is considerable evidence that keto diets can significantly enhance insulin sensitivity, especially in individuals with insulin resistance or type 2 diabetes. There is also strong support for the notion that brain sensitivity to leptin, a hormone that regulates satiety, also improves during nutritional ketosis. Therefore, an enhanced response to thyroid hormones while on the carnivore diet would align well with these other documented increases in hormone sensitivity.

 

Another argument comes from the nuance regarding thyroid hormone activity and its sensitivity in peripheral tissues. This is a significant aspect of thyroid physiology yet is not detectable via standard bloodwork:

 

• One study found that reduced sensitivity to thyroid hormone in peripheral tissues can result from defects in thyroid hormone transport to cells, intracellular metabolism, and various cytosolic and nuclear mechanisms.
• Another study reported that biological markers such as plasma fibronectin, serum procollagen-III-peptide, and sex hormone-binding globulin (SHBG) can reflect thyroid hormone effects at the peripheral tissue level. Changes in these markers can indicate discrepancies between pituitary and peripheral tissue responses to thyroid hormone therapy.
• Transporters, deiodinases, and receptor coregulators regulate the intracellular availability and action of thyroid hormone. These factors can significantly influence tissue-specific sensitivity to thyroid hormone, indicating that circulating hormone levels don’t fully represent intracellular hormone activity.

 

These various studies show that peripheral tissue sensitivity to thyroid hormone is influenced by complex mechanisms not detectable through bloodwork. This leads to a theoretical deduction that thyroid hormone function on a low-carb diet may also differ in terms of its effects on peripheral tissue. Low-carb individuals may have full thyroid functionality at lower ranges because there is potentially improved thyroid hormone function in the periphery tissues. Still, more research needs to be done on ketogenic diets and thyroid function to know with better certainty.    

 

Despite these arguments, recommendations frequently surface online advising a daily carbohydrate intake of at least 100 grams to sustain “normal thyroid function.” Such an intake level, even of low-glycemic carbohydrates, would typically inhibit nutritional ketosis in most adults, consequently raising blood thyroid hormone levels. 

 

What About Keto Studies Showing T3 Reduction In the Short Term?

Studies reflect the initial reduction of T3 when adopting a keto diet, aligned with our explanation above about how various factors including calorie restriction and weight loss can temporarily reduce thyroid activity. T3 levels can lower with just four days of undereating and exercise.

 

• Short-term studies show a significant reduction in T3 levels within three weeks of starting a keto diet due to the initial adaptation to ketosis which influences thyroid hormone metabolism.
• A four-week keto study observed a significant decrease in T3 levels and an increase in T4 levels, indicating a shift in thyroid hormone production and conversion during the early phases of the keto diet.
• This is a commonly-cited, fearmongering study showing the initial drop of T3. Note the sample size of 11 men and the timeframe of 11 days, making this a very limited, short-term study. Thyroid medications can take months, even years to achieve better thyroid hormone balance—this study fails to consider these nuances despite arguing that carb deprivation causes endocrine and metabolic dysregulation. 

 

Long-term keto studies in adult populations do not show a continued reduction in T3 levels. During the weight-maintenance phases of these long-term studies, concentrations of T3 were increased when carbohydrate calories were fully substituted for fat in the diet. This means that once calorie restriction was stopped and adequate fat was consumed, T3 levels increased naturally.

 

Conflicting Keto and T3 Studies In Pediatric Epilepsy Cases

Another study often cited as an argument that carbs are needed for proper thyroid health is this pediatric study of 120 children using keto diets therapeutically for pharmacoresistant epilepsy. Of the 120 children, ages four to 10 years old, eight, seven, and five patients (20 patients total) were diagnosed with hypothyroidism and given L-thyroxine medication at one, three, and six months of the keto diet, respectively.  

 

It’s important to consider the following: 1) Does this apply to adults? 2) Does this apply to the population of people without epilepsy? According to the CDC, about 1% of US adults have active epilepsy. 

 

Another consideration is this retrospective chart review study of 28 pediatric patients who followed a keto diet for more than six years at Johns Hopkins Hospital. It contains a smaller sample size population but follows patients that were aged seven to 23 years old at the time of review. The diet duration ranged from six to 12 years, with 19 of the patients remaining on the diet currently. Documentation of lab markers was presented approximately every six to 12 months with no incidences of hypothyroidism. 

 

So, this further illuminates additional discussion needed when it comes to pediatric epilepsy cases. These significant factors need to be considered as we simply can’t infer that keto diets are the cause of some of the adverse events observed. 

 

Lastly, there are currently no published human studies or literature showing hypothyroidism as a long-term consequence in adults following a keto diet. 

 

Are Low Thyroid Markers On a Carnivore Diet Problematic?

The critical question remains: Are the elevated thyroid hormone levels among those who eat carbs genuinely normal, or do they represent an overactive thyroid state induced by excessive carb consumption? 

 

Could the lower T3 levels observed with a carnivore diet actually reflect optimal T3 sensitivity and therefore represent the true physiological norm for humans?

          

Another suggested “solution” for addressing this supposed issue is to periodically indulge in high carb consumption, whether a few days each week or one week per month. This approach leads to a metabolic fluctuation that can have adverse effects. 

 

It is established that adapting fully to nutritional ketosis takes several weeks, but this adaptation is largely undone by just a few days of consuming 100 grams or more of carbohydrates daily. Why encourage the body to adapt to ketosis only to frequently disrupt this state with high carb intake? 

 

Considering that sustained levels of beta-hydroxybutyrate, a marker of nutritional ketosis, help reduce oxidative stress and inflammation, why would one choose to intermittently halt this beneficial effect? 

 

If low-carb diets such as Carnivore adversely affect thyroid function, you would expect to see a significantly higher incidence of thyroid failure (hypothyroidism) among individuals adhering to any keto diet. (We don’t see this in our practice and often see the reversal of hypothyroidism and Hashimoto’s.) 

 

There might be a subset of individuals particularly sensitive to carbohydrate restriction who could experience such effects. But how can we determine if this is the case? Over the past decade, several extensive randomized studies lasting three months or longer have examined the effects of low-carb and keto diets. Let’s review these studies to see if there were any instances of hypothyroidism caused by a low-carb diet. 

 

 

Studies referenced:

• A Randomized Trial of a Low-Carbohydrate Diet for Obesity
• A low-carbohydrate, ketogenic diet versus a low-fat diet to treat obesity and hyperlipidemia: a randomized, controlled trial
• Long-term use of the ketogenic diet in the treatment of epilepsy
• Comparison of the Atkins, Zone, Ornish, and LEARN diets for change in weight and related risk factors among overweight premenopausal women: the A TO Z Weight Loss Study: a randomized trial
• Weight Loss with a Low-Carbohydrate, Mediterranean, or Low-Fat Diet
• Comparison of low fat and low carbohydrate diets on circulating fatty acid composition and markers of inflammation
• A Randomized Pilot Trial of Moderate Carbohydrate Diet Compared to a Very Low Carbohydrate Diet in Overweight or Obese Individuals with Type 2 Diabetes Mellitus or Prediabetes
• Effects of low-carbohydrate and low-fat diets: a randomized trial
• Effect of Calorie-Unrestricted Low-Carbohydrate, High-Fat Diet Versus High-Carbohydrate, Low-Fat Diet on Type 2 Diabetes and Nonalcoholic Fatty Liver Disease

 

Although the studies in question were not specifically designed to investigate thyroid health, it is difficult to overlook cases of overt hypothyroidism. These studies were conducted under the supervision of highly qualified physicians, ensuring that any new occurrence of hypothyroidism would have been noted as a “serious adverse event” linked to the low-carbohydrate, high-fat (LCHF) diet. 

 

Remarkably, among 543 closely observed participants, there were no reported cases of hypothyroidism.

 

A Deeper Look Into the Science Behind Low-Carb Diets

 

 

 

Each year, tens of thousands, if not hundreds of thousands, of people in the US and other developed countries earnestly commit to a low-carb diet. Oftentimes, individuals turn to this diet as a last resort after traditional diets fail to yield results. 

 

It’s reasonable to assume that some of these people might already be experiencing early, mild symptoms of thyroid conditions such as Hashimoto’s thyroiditis and choose a low-carb diet in response. Their symptoms of hypothyroidism may become more pronounced over time, which could mistakenly suggest an increase in diagnosed hypothyroidism post-adoption of an LCHF diet, creating an apparent correlation that does not equate to causation. 

 

However, based on the current review of published data, there appears to be minimal evidence that a properly managed keto diet such as Carnivore leads to significant thyroid issues.

 

Additionally, based on our clinical practice, patients with existing thyroid issues often report reduced symptomology when they switch to the carnivore diet.

 

Addressing the Root Cause of Thyroid Issues

 

 

 

If you’re healthy and thriving on a carnivore diet and happen to receive low thyroid markers on your blood work, we recommend considering the above hypothesis. If you feel better and don’t have symptoms of hypo or hyperthyroid, our best recommendation is not to go looking for problems.

 

Bloodwork reference ranges are typically established based on statistical averages derived from a large sample of the general population. These ranges represent what is considered normal for a healthy individual within that population. It’s important to note that these averages may not always account for individual variations such as age, sex, ethnicity, and specific health conditions. While reference ranges provide a useful guideline for interpreting lab results, they should always be considered alongside a patient’s overall clinical context and personal health history. 

 

Most Americans are overweight and unwell, so maybe the numbers we are targeting aren’t ideal ranges. Our practice never looks at bloodwork or functional tests alone. A person’s medical history is one of the most important pieces for personalized care. (Treat the patient that has the disease, not just the disease).

  

Now if you are experiencing related symptoms or have a history of thyroid issues, it’s time to get to the root cause.   

 

Here are some root causes of thyroid disorders:

 

Iodine Deficiency

 

 

The most common cause of thyroid issues globally is iodine deficiency which can develop into hypothyroidism and goiter. Many iodine-rich foods are from the animal kingdom including fish, shellfish, dairy, eggs, chicken, and beef liver.

 

Tyrosine Deficiency

Tyrosine deficiency is less common but is associated with reductions in thyroid hormone levels. As the precursor for thyroid hormone, healthy levels of this non-essential amino acid (because the body can make tyrosine from the amino acid phenylalanine) are required. This deficiency was observed most significantly in vegans which comes as no surprise considering tyrosine (and phenylalanine) are most abundant and bioavailable from animal proteins. The competition for amino acid absorption comes from incomplete plant protein sources, making it essential to eat adequate amounts of animal protein. 

 

Pro-Tip: Phenylalanine is one of the aromatic amino acids that helps block some of the damage from glyphosate in the body. If you eat a lot of GMO plants sprayed with glyphosate, you use up a lot of the phenylalanine (along with tyrosine and tryptophan).  Since phenylalanine is a precursor for tyrosine, the need for tyrosine then becomes more essential. Simply sticking to fatty meat is ideal. 

 

Autoimmune Disease

In iodine-sufficient areas, the most prevalent cause of thyroid disorders is autoimmune disease. Conditions such as Hashimoto’s thyroiditis and Graves’ disease are common autoimmune conditions that impact thyroid function. 

 

The caveat here is that autoimmune disease isn’t always a root cause—if you suffer from impacted thyroid function due to autoimmunity, there may be deeper issues at play. Certain medical conditions such as Chronic Inflammatory Response Syndrome (CIRS) and leaky gut syndrome are believed to trigger autoimmunity. 

 

Environmental Factors

Various environmental factors can also play a significant role in developing thyroid disorders. Environmental factors such as selenium and vitamin D deficiency, radiation exposure, cigarette smoking, viral infections, chemical contaminants, and drugs can also play a role in developing autoimmune thyroid diseases. 

 

Mold exposure is also linked to thyroid dysfunction. If mold is the root cause or contributing to your thyroid condition, it’s imperative to get out of exposure. Individuals suffering from mold illness are advised to look into CIRS and the Shoemaker protocol—the only peer-reviewed, clinically replicable treatment for mold toxicity and other biotoxin illnesses.

 

The pituitary gland is impacted by CIRS through the biotoxin pathway. Since the pituitary gland is responsible for signaling TSH to release, once impacted by CIRS, there can be deeper structural issues acting as a root cause for thyroid issues.  

 

Mold exposure results in thyroid lab patterns known as non-thyroidal illness syndrome (NTIS). NTIS refers to thyroid lab changes that can be caused by multiple medical conditions. It’s important to find what’s causing this lab pattern. 

 

However, the problem is that to determine the NTIS pattern, the standard testing of TSH and free T4 is not adequate. Further testing for free T3 and rT3 will also be needed. 

 

NTIS will have the following thyroid lab pattern:

• Low free T3
• Normal to high rT3
• Low to normal free T4
• Normal TSH

 

Pro-Tip: Taking T3 thyroid hormone medication instead of T4 has been shown to improve symptoms in patients with mold-related thyroid dysfunction. This acts as a temporary band-aid for symptom relief while patients pursue root-cause healing from mold exposure.

 

Certain Viruses

If you’ve ever suffered from Epstein-Barr Virus (EBV) or mononucleosis (mono), it can be the root cause of Hashimoto’s thyroiditis or other thyroid diseases. EBV is known for its ability to remain dormant in the body and can reactivate later in life, potentially triggering autoimmune conditions. Hashimoto’s thyroiditis, an autoimmune disorder where the immune system attacks the thyroid gland, has been linked to previous EBV infections. 

 

People with a history of EBV or mono who are experiencing thyroid symptoms may want to consider getting tested for EBV activation. This can involve blood tests to check for EBV antibodies, which can indicate whether the virus is active or reactivated in the body. Identifying an EBV connection can be crucial for addressing the underlying cause of thyroid issues.

 

Closing Thoughts On the Carnivore Diet and Low Thyroid

Similar to how you become insulin-sensitive on the carnivore diet and other low-carb diets, you can also become thyroid-sensitive with this way of eating. If you’re healthy, don’t have any of the thyroid dysfunction symptoms listed above, and are on Carnivore, we wouldn’t worry about chasing numbers. 

 

However, if you are experiencing thyroid disorder symptoms, it’s up to you if you want to try thyroid medication as a temporary support until you find your root cause. If you’re on a particular thyroid medication for about three months and don’t feel incrementally better, the diagnosis or protocol is likely wrong.

 

And if your practitioner is telling you that low T3 heightens your risk for dementia, this requires a more nuanced view as well. First and foremost, it doesn’t take into account individuals on low-carb diets. While some studies indicate that hypothyroidism is associated with an increased risk for dementia, others report no association and that thyroid hormone therapy can actually increase the risk.

 

Getting to the root cause should always be the priority when it comes to thyroid dysfunction and any other health concern. We always recommend working with a trusted practitioner who can with a more holistic view while helping you determine the root cause of your symptoms and conditions. 

 

Work With Our Trusted Carnivore Diet Functional Nutritional Therapy Practitioners

The Nutrition with Judy practice is honored to be a trusted carnivore diet practitioner support serving clients from around the globe. We’re passionate about helping our clients achieve root-cause healing in order to lead the best quality of life possible that’s nearly symptom-free. Our team is dedicated to debunking mistruths and providing better context around nuanced topics. We welcome you to explore our free resources and are always available to support you through personalized protocols. Our Symptom Burden Assessment (SBA) is the perfect starting point for discovering your root cause and is required to work with our team— you can learn more in-depth about this powerful tool here.