The Thyroid Gland and Hormones
The thyroid gland is a butterfly-shaped two-inch long, brownish red, highly vascular gland found inside the neck, under the larynx or voice box. It has two lobes located on each side of the windpipe that are both connected by a tissue called the isthmus.
A normal thyroid gland weighs somewhere between 20 and 60 grams. The thyroid is responsible for producing three types of hormones crucial for metabolism and many other bodily functions. The hormones produced by the thyroid are: Tri-iodothyronine (T3), Thyroxine (T4), Di-iodothyronine (T2).
These hormones, when selected, interact with all other hormones in the body, including insulin, cortisol, and sex hormones like oestrogen, progesterone, and testosterone. The fact that these hormones are all tied together and are in constant communication explains why a less-than-optimal thyroid status is associated with so many widespread symptoms and diseases. Almost 90 percent of the hormone produced by the thyroid is the form of T4, the inactive form. This form, with a help of an enzyme, is converted by the liver to T3, the active form. T2, on the other hand, is currently the least-understood component of thyroid function and the subject of a number of ongoing studies.
In normal physiological conditions the thyroid produces correct amounts of T3 and T4, which control the metabolism of every cell in the body. If there are inadequate levels of T3, either by scarce production or not converting properly from T4, the whole system would be compromised. T3 is critically important because it directs the nucleus of the cells to send messages to the DNA to restore the metabolism by burning fat. This is how T3 lowers cholesterol levels, regrows hair, and helps keep us lean. In pathological conditions T3 levels are disrupted, mainly by nutritional imbalances, toxins, allergens, infections and stress. This would lead to a series of complications; including thyroid cancer, hypothyroidism, and hyperthyroidism, which today are three of the most prevalent thyroid-related diseases.
Hypothyroidism occurs when the thyroid produces too little thyroid hormone, a condition that is often linked to iodine deficiency. The most common symptoms of hypothyroidism are:
- Lethargy - Fatigue and lack of energy are typical signs of thyroid dysfunction and would manifest with feeling of having not enough energy to exercise, heavy or tired head and sleepy feeling.
- Weight gain – Easy weight gain or difficulty losing weight, despite an aggressive exercise program and watchful eating, is another indicator.
- Rough and scaly skin and/or dry, coarse, and tangled hair
- Hair loss - Unexplained hair loss occurs could be a sign of thyroid deficiency
- Sensitivity to cold – Feeling cold all the time is also a sign of low thyroid function. Anyone diagnosed with hypothyroidism is slow to warm up, even in a sauna, and don't sweat with mild exercise.
- Low basal temperature
An overactive thyroid secretes too much T4, causing some of the body functions to accelerate. This condition is more common in women and can occur at any age – about eight in 100 women and one 1 in 100 men develop hyperthyroidism at some point in their lives. Symptoms associated with hyperthyroidism are:
- Feeling restless, nervous, emotional, irritable, sleeping poorly
- Difficulty concentrating
- Frequent bowel movements
- Irregular menstrual periods in women
- Weight loss (or weight gain, in rare cases)
- Rapid, forceful, or irregular heartbeat
- Lack of menstrual periods in women
- Protruding eyes
Untreated hyperthyroidism can lead to heart problems like atrial fibrillation, cardiomyopathy, angina, heart failure and infertility in women.
What disturbs thyroid function
Gluten – Gluten could be a major risk factor for thyroid dysfunction, as a result of inflammation. Gluten causes autoimmune responses in many people and can be responsible for Hashimoto's thyroiditis, a common autoimmune thyroid condition. Approximately 30 percent of the people with Hashimoto's thyroiditis have an autoimmune reaction to gluten. Gluten sensitivity can cause malfunction in the gastrointestinal system, in which case the foods would fail to be digested, often leading to a leaky gut syndrome. These food particles can then be absorbed into the bloodstream, where the body misidentifies them as antigens (substances that shouldn't be there) produces antibodies against them. These antigens are similar to the molecules in the thyroid gland. Because of this, the body accidentally attacks the thyroid. This is known as an autoimmune reaction, in which the body attacks itself.
Soya – Unfermented soya products such as soy meat, soy milk and soy cheeses have been linked to various health concerns such as: digestive stress, immune system weakness, cognitive decline, reproductive disorders, infertility, and thyroid dysfunction. The phytoestrogens found in soya are potent anti-thyroid agents that cause hypothyroidism. In infants, consumption of soya formula has been linked to autoimmune thyroid disease.
Bromines – Bromines are a common endocrine disruptor. Because bromide is also a halide, it competes for the same receptors that are used in the thyroid gland to capture iodine. This will inhibit thyroid hormone production resulting in a low thyroid state. When ingested or absorbed bromine can displace iodine and this iodine deficiency could lead to an increased risk for cancer of the breast, thyroid gland, ovary, and prostate. Thyroid dysfunction caused by bromine would lead to skin rashes, severe acne, loss of appetite, abdominal pain, fatigue, a metallic taste in the mouth, and cardiac arrhythmias.
Stress and Adrenal Function – Stress is one of the worst thyroid offenders. The thyroid function is intimately tied to the adrenal function, which is intimately affected by how we handle stress. Many of us are almost always under chronic stress, which results in increased adrenaline and cortisol levels, and elevated cortisol has a negative impact on thyroid function. Thyroid hormone levels drop during stressful times. In the case of chronic stress, the flood of stress chemicals – adrenaline and cortisol – produced by the adrenal glands interfere with the thyroid hormones, causing many health-related issues like obesity, high blood pressure, high cholesterol, unstable blood sugar levels. A prolonged stress response can lead to adrenal exhaustion, which is also known as adrenal fatigue and which is often found alongside thyroid disease.
How to improve thyroid function
Maintain healthy Iodine levels – Iodine is essential for healthy thyroid function and efficient metabolism. It is also a potent anti-bacterial, anti-parasitic, anti-viral and anti- cancer agent. It has four significant roles in the body, namely to maintain weight and metabolism, to develop brain and cognitive function in children, to optimise fertility, and to strengthen the immune system.
Selenium - The thyroid is the organ with the highest amount of Selenium per gram of tissue. The selenium is crucial for normal thyroid function. The selenium in the thyroid gland is incorporated into Selenoproteins which have an important antioxidant activity.
The antioxidant function of selenoproteins is to remove oxygen free radicals generated during the production of thyroid hormones. In the thyroid, Selenium is also incorporated into Iodothyronine Deiodinases (enzymes important in the activation and deactivation of thyroid hormones) in the form of an amino acid Selenocysteine, through which it plays an essential role in the metabolism of thyroid hormones. The iodothyronine deiodinases catalyse the conversion of T4 to its biologically active form T3, through the removal of an iodine atom from the external ring.
Get adequate amounts of sleep - Inadequate sleep contributes to stress and prevents the body from regenerating fully.
Exercise - Exercise directly stimulates the thyroid gland to secrete more thyroid hormone and increases the sensitivity of all other tissues to thyroid hormone. It is even thought that many of the health benefits of exercise stem directly from improved thyroid function.
BSc Alternative Medicine; MSc Pharmacology
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