The Importance of Thyroid Health
The Importance of Thyroid Health
What is the Thyroid?
The thyroid is a butterfly-shaped gland located at the base of the neck that secretes hormones including thyroid hormones (thyroxine, or T4, and triiodothyronine, or T3) and calcitonin (calcitonin is involved in calcium balance but for the purposes of this blog we will focus on thyroid hormones).
The thyroid gland is part of our endocrine, or hormonal system, that has far-reaching effects on overall health and wellbeing. Thyroid hormones are essential for normal growth and development, especially of the nervous system, as well as for metabolic regulation, which controls many functions including energy expenditure and body temperature. Learning about the thyroid can be a complex endeavor, this blog will provide the simplified background necessary to understand what is clinically relevant.
Thyroid hormones are made and stored within the thyroid gland. They are made from the amino acid tyrosine and contain the element iodine (T4 contains 4 iodine molecules whereas T3 contains 3). Thyroid peroxidase, or TPO, is the primary enzyme involved in the production of thyroid hormones. The majority of thyroid hormone produced in the thyroid gland is T4, the inactive form, which is released into the bloodstream attached to a transporter protein until ready for use. When ready for use, T4 is converted in various tissues (predominantly the liver) into T3, the active form that can be used by tissues for its purpose. Thyroxine 5-deiodinase is the enzyme responsible for this conversion by removing 1 iodine molecule from T4 to make T3.
Like other hormones, thyroid hormone production is regulated by a negative feedback system involving the hypothalamus (a region of the brain above the pituitary gland), anterior pituitary (front portion of the pituitary gland), and thyroid gland. If thyroid hormones are low, the hypothalamus releases a hormone called thyrotropin-releasing hormone, or TRH, which stimulates the anterior pituitary to release a hormone called thyroid stimulating hormone, or TSH, which stimulates the thyroid gland to increase release of T4 and T3. Conversely, if thyroid hormones are high, TRH release from the hypothalamus is inhibited, which suppresses the entire pathway downstream leading to decreased release of T4 and T3 from the thyroid gland.
Hypothyroidism vs. hyperthyroidism
Every cell in the body has thyroid hormone receptors, which means that thyroid hormones have some degree of influence on all cellular functioning in the body, affecting practically every organ system. This explains why disorders that affect the amount of thyroid hormone produced, whether it be too much or too little, have such profound and wide-ranging consequences on the body.
In hypothyroidism, the thyroid gland is underactive and under-produces thyroid hormone (less than what the body needs). In hyperthyroidism, the thyroid is overactive and over-produces thyroid hormones (more than what the body needs). This blog will focus on the primary causes of both hypo- and hyper-thyroidism.
Let’s start with hypothyroidism because it is the most common thyroid disorder. According to the NIH, nearly 5 out of 100 Americans ages 12 and older have hypothyroidism. There are several causes of hypothyroidism, but the number 1 cause is Hashimoto’s thyroiditis, or HT. HT is an autoimmune disorder that affects the thyroid gland; antithyroid antibodies lead to destruction of the thyroid’s hormone-producing cells causing a subsequent decline in thyroid hormone production. Common risk factors for the development of HT include being a female and older than 60.
Hyperthyroidism on the other hand is less common than hypothyroidism, although still a prevalent thyroid disorder. According to the NIH, about 1 out of 100 Americans ages 12 and older have hyperthyroidism. There are several causes of hyperthyroidism, but the number 1 cause is Grave’s disease, or GD. GD is an autoimmune disorder that affects the thyroid gland; antithyroid antibodies lead to upregulation of the thyroid’s hormone-producing cells causing a subsequent rise in thyroid hormone production. Common risk factors for the development of GD include being a female and younger than 40.
Symptoms of Thyroid Disorders
Symptoms of both hypo- and hyper-thyroidism can vary greatly depending on the severity of disease. Abnormal levels of thyroid hormone have significant impacts on both physical and mental performance and can have detrimental complications on health if left un-treated. Since thyroid hormones control metabolism, hypothyroidism decreases metabolic rate and causes many body functions to slow down, whereas hyperthyroidism increases metabolic rate and causes many body functions to speed up. Note that both conditions can cause a goiter (an enlarged thyroid gland). Here is a non-exhaustive list of signs and symptoms that highlights the differences between hypo- and hyper-thyroidism:
If thyroid dysfunction is suspected, it is important to see a doctor to rule out hypo- or hyper-thyroidism. Full evaluation of the thyroid should include a medical intake, physical examination, laboratory testing, and if indicated, diagnostic testing. Let’s discuss lab testing further, as this is a critical part of diagnosis and management of thyroid disorders. Here is a brief description of the primary blood markers tested:
TSH: this is the most common marker used to assess thyroid function. A high TSH may indicate hypothyroidism. A low TSH may indicate hyperthyroidism.
T4: high levels may indicate hyperthyroidism and low levels may indicate hypothyroidism.
Total: total T4 measures both bound and unbound T4.
Free: free T4 measures only unbound T4.
T3: high levels may indicate hyperthyroidism and low levels may indicate hypothyroidism.
Total: total T3 measures both bound and unbound T3.
Free: free T3 measures only unbound T3.
Reverse T3 (rT3): rT3 is converted from T4 typically in cases of extreme stress (such as trauma, surgery, or chronic stress) and is inactive. A high rT3 may contribute to hypothyroidism, as it shunts the conversion from T4 to rT3 instead of T3.
Antibodies (Ab): antibodies are immune proteins (immunoglobulins) that recognize molecules as foreign and target them for destruction. Thyroid antibodies indicate autoimmunity.
TPO Ab: these antibodies are typically elevated in HT.
TG Ab: these antibodies are typically elevated in HT.
TSI Ab: these antibodies are typically elevated in GD.
Note that most conventional doctors only test TSH and possibly free T4 to screen for thyroid disorders. However, this does not account for the entire picture and thyroid disorders can be present with a normal TSH and/or free T4. If you would like additional markers tested, it is recommended to advocate for yourself or visit a naturopathic/integrative doctor. Additionally, there are other markers that can be tested not listed above as well as different patterns of thyroid markers/dysfunction to be identified, both of which are beyond the scope of this post.
Treatment of Thyroid Disorders
The basic treatment goal for hypothyroidism is to increase thyroid hormones and enhance their effect in the body. Conventionally, this is done by replacing thyroid hormone with pro-thyroid medications (such as Levothyroxine, a synthetic form of T4). The basic treatment goal for hyperthyroidism is to decrease thyroid hormones and diminish their effect in the body. Conventionally, this is done by procedures/surgeries (that destroy thyroid cells or remove thyroid tissue) and anti-thyroid medications. Complications of either condition are addressed individually. This conventional approach is necessary and lifesaving in many situations.
However, if we also look at thyroid dysfunction through a functional lens, we see that there are often more pieces to the puzzle as well as less invasive methods available. For example:
- Replacing thyroid hormone may restore bodily functioning, however it does not address the root cause, such as the autoimmunity of HT
- Hormone replacement therapy may not fix downstream or upstream problems, such as an issue with conversion of T4 to T3 or miscommunication between the hypothalamus-pituitary-thyroid axis
- Standard hormone replacement therapy consists of synthetic hormones, however natural sources of these hormones exist in the form of desiccated thyroid from animals
- Thyroid surgeries/procedures can be invasive and have long-term consequences, such as the induction of hypothyroidism from destruction or removal of thyroid tissue
- There are numerous aspects that can be targeted to support thyroid health and resolve thyroid dysfunction, such as gut and liver health, adrenal function, nutritional status, environmental exposures and detoxification, underlying infections, immunity, and inflammation
- Natural modalities that can be used safely and effectively in the treatment and management of thyroid disorders include diet and lifestyle modification, nutritional supplementation, herbal medicine, glandular medications, and much more!
Nutrition for the thyroid
The importance of nutrition for the thyroid warrants its own discussion, and here’s why. Under- or over-nutrition can contribute to the development of thyroid disorders (e.g. an iodine deficiency can cause hypothyroidism). Thyroid disorders each have their own associated nutritional deficiencies (e.g. vitamin B12 is often deficient in both HT and GD). Nutrition has a great impact on the immune system (e.g. vitamin D status and leaky gut). Certain nutrients are necessary for the synthesis (e.g. tyrosine and iodine) of thyroid hormones and conversion (e.g. selenium and zinc) of T4 to T3. Certain foods may aggravate thyroid disorders (gluten has been shown to exacerbate HT, goitrogenic foods have been shown to inhibit thyroid hormone synthesis). Shall I keep going or have I convinced you?
The causes of HT and GD are not fully understood although they are thought to involve interactions between environmental and genetic factors. Regardless, there are many things that can be done to reduce your risk of developing a thyroid disorder, relieve the signs/symptoms of an active thyroid disorder, and possibly even reverse an active thyroid disorder. Clearly, having a naturopathic doctor (ND) in your healthcare team crucial, whether they are your sole or adjunctive provider. NDs have such a variety of tools to offer that can be tailored to your specific needs and wants. Call LIVV today to schedule an appointment and address any concerns regarding your thyroid health! Always contact your medical or naturopathic doctor before trying something new for your health/thyroid condition.
Written by Jordan Valdez
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