special report THYROID HEALTH
Feed your thyroid
Your thyroid gland produces hormones that impact such fundamental aspects of your life as sleep, body temperature, metabolism, fertility and mood. With one in three Australians suffering from low thyroid hormone levels, we dig into how your thyroid works and how you can keep it healthy.
Words LISA GUY
Photography Getty Images
The thyroid gland is one of the most important glands in the human body. It controls nearly all of your cells and is vital for healthy metabolism, growth and development. This tiny butterfly-shaped gland, which makes up part of your endocrine system, produces hormones that help regulate many vital functions in the body. A disturbance in thyroid function can greatly impact your physical and mental health and wellbeing. This is why, when the thyroid is not working optimally, it can affect the functioning of almost every system of the body, including your emotional state.
Thyroid hormone regulation
Located at the base of the neck, the thyroid gland is regulated by what is called a negative feedback loop, which includes the hypothalamus, pituitary gland and the thyroid gland. The hypothalamus secretes thyrotropin-releasing hormone (TRH), which stimulates the pituitary gland to produce thyroid-stimulating hormone (TSH), which in turn stimulates the thyroid gland to make and secrete thyroid hormones.
The thyroid produces two main types of hormones: triiodothyronine (T3) and thyroxine (T4). T3 is the active form of thyroxine. The liver, gut and kidneys convert T4 into its active T3 form that can be used by cells in the body. There is a third hormone produced by the thyroid called calcitonin, which is involved in calcium and bone metabolism.
If your T3 or T4 levels are too high the hypothalamus and pituitary gland will stop secreting hormones. If your T3 and T4 levels are too low the hypothalamus and pituitary gland will increase thyroid hormone secretion to help bring the body back into balance. If your thyroid function test results show high TSH levels, this may indicate that your thyroid is underactive and not producing enough thyroid hormones. Low TSH on the other hand may indicate that your thyroid is overactive and producing too much thyroid hormone.
Role of thyroid hormones
Thyroid hormones play a major role in metabolism and how nutrients from the foods you eat are converted into energy to fuel the body. They regulate body temperature, heart rate and digestive function, and they can also affect fertility.
Thyroid hormones influence your sleep, and your brain function and development. They also help regulate your “feel-good” neurotransmitters like serotonin and dopamine that control your mood.
Additionally, these hormones also play a role in maintaining healthy bones, and they assist the liver with breaking down cholesterol and controlling triglyceride levels.
Photography Getty Images
Hypothyroidism
Hypothyroidism is the most prevalent thyroid disorder in Australia, affecting one in three Australians. Hypothyroidism is a condition where the thyroid gland is unable to make and release enough thyroid hormones. Women, particularly women over 60, are more vulnerable to developing hypothyroidism than men. People with pre-existing autoimmune diseases such as rheumatoid arthritis, coeliac disease and type-1 diabetes are at a greater risk of hypothyroidism.
Common
causes
of
hypothyroidism
In Australia, Hashimoto’s thyroiditis is the most common cause of hypothyroidism. Hashimoto’s is an autoimmune disease where the immune system starts mistakenly attacking the thyroid gland, causing inflammation and thyroid cell destruction.
Other causes of hypothyroidism include poor diet lacking in iodine and selenium, radiation therapy or surgery and genetic disorders. Issues with the pituitary can affect TSH production and can result in hypothyroidism.
Common
symptoms
of
hypothyroidism
One of the most notable symptoms of hypothyroidism is sluggish metabolism. When your metabolism slows down you put on weight easily and feel tired all the time.