The Body’s Metabolic Powerhouse
The thyroid gland, a small butterfly-shaped organ located at the base of your neck, plays an outsized role in regulating your body’s metabolism and overall energy levels. Though it’s small in size, the thyroid’s influence is vast, impacting nearly every cell, tissue, and organ in your body.
At its core, the thyroid is responsible for producing hormones that control the speed at which your body’s systems operate. The two primary hormones produced by the thyroid are thyroxine (T4) and triiodothyronine (T3).
These hormones are vital for regulating metabolism, which includes the conversion of food into energy, controlling body temperature, and maintaining proper heart rate, muscle strength, and digestive function.
The thyroid doesn’t work alone. It’s part of a larger feedback loop involving the hypothalamus and pituitary gland, located in the brain. Here’s a simplified look at how it all works:
Hypothalamus: This region of the brain monitors the body's needs and sends a signal, in the form of thyrotropin-releasing hormone (TRH), to the pituitary gland.
Pituitary Gland: In response to TRH, the pituitary releases thyroid-stimulating hormone (TSH) into the bloodstream. TSH is the hormone that tells the thyroid gland to produce and release T4 and T3.
Thyroid Gland: The thyroid responds to TSH by producing T4 and T3. T4 is the inactive form, which is converted into the more active T3 in tissues like the liver and kidneys. T3 then enters cells to regulate the body's metabolic rate.
Feedback Loop: As levels of T4 and T3 increase, they signal back to the hypothalamus and pituitary to reduce TRH and TSH production, ensuring a balanced and stable metabolism.
A healthy thyroid is essential for overall well-being. When the thyroid produces too much or too little hormone, it can lead to significant health issues:
Hyperthyroidism: This condition occurs when the thyroid is overactive, producing excessive amounts of thyroid hormones. Symptoms can include weight loss, increased heart rate, anxiety, and heat intolerance.
Hypothyroidism: When the thyroid is underactive and doesn’t produce enough hormones, it leads to symptoms such as weight gain, fatigue, depression, and cold intolerance.
Goiter: An enlargement of the thyroid gland, often visible as a swelling at the base of the neck. This can occur with both hyperthyroidism and hypothyroidism.
Thyroid Nodules: Small lumps or growths within the thyroid gland, which are usually benign but can sometimes be cancerous or cause imbalances in hormone production.
Supporting Your Thyroid:
Unfortunately, one of the worst disruptors of this delicate thyroid pathway are seed oils (“vegetable” oils). Most Americans have unknowingly eaten these their entire lives, slowly damaging their thyroid function and putting them into a state of “subclinical hypothyroidism.” Most Americans continue to consume these by consistently eating out at restaurants and eating ultra processed foods. Low thyroid function raises estrogen and cortisol, which are stress hormones that feedback to lower thyroid hormones even further.
The thyroid and the liver work together to convert T4 to T3 (the active form), but only when you have enough glucose. As we have discussed before, most Americans have impaired glucose burning capabilities, are in a state of slow fat burning/high fat storage (hibernation) and would benefit greatly from some thyroid supplementation, which we will get into next time in greater detail.