Condition - How do I know if I am hypothyroid?
One question I am frequently asked in my practice is how to improve energy and combat tiredness. While there is an array of causes of fatigue, one organ worth paying attention to is our thyroid. An under-functioning thyroid will frequently present with these symptoms, among many others.
The thyroid is a small, butterfly-shaped gland located in the neck. It releases two hormones, thyroxine (T4) and triiodothyroxine (T3). These hormones control the metabolic rate of all cells throughout the body. Many people believe that the thyroid simply influences our weight, but it has a much more far-reaching role in our body. Metabolism refers to all the chemical reactions of the body and, also, how energy is made available. Therefore, the thyroid influences every system, organ and muscle in the body. Problems with an under-functioning thyroid gland, known as hypothyroidism, can be the cause of many recurring symptoms and fatigue. Diminished thyroid activity decreases metabolic rate, affecting every cell in the body, and so can influence virtually all bodily functions.
The release of hormones by the thyroid gland is controlled by an ingenious feedback mechanism. The hypothalamus in the brain tells the pituitary gland to release thyroid-stimulating hormone (TSH). The TSH in the bloodstream then signals the thyroid to make and release thyroid hormones. However, this feedback loop can be affected by emotions, stress and nutritional status.
The hormones produced by the thyroid gland are transported to their site of action, bound to a carrier protein. It is only when the hormones are freed from their transport protein that they become active, or free. Free T3 is the hormone that is chemically active, while T4 is a non-active form requiring conversion to T3, the active form. T3, however, has an extremely short life span, so the thyroid produces more T4 than it does T3. Most synthetic thyroid hormones, such as thyroxine, are primarily T4. If certain nutrients are in short supply, the body may have difficulty converting T4 to T3, which can also create further difficulties for doctors in getting the levels of synthetic thyroxine adjusted appropriately.
Symptoms of an underactive thyroid are many and varied, but can include fatigue, especially on waking, feeling the cold easily, cold hands and feet, dry skin and hair, depression, poor memory, insomnia, muscle and joint weakness and stiffness, poor immune function, high cholesterol, heavy periods, constipation and weight gain.
Low thyroid function may be the result of a number of factors:
Inflammation of the thyroid, resulting from a viral infection, or an autoimmune reaction or surgical removal of part of the thyroid gland – a treatment often used for an overactive thyroid gland – may ultimately result in an under-functioning thyroid.
Whiplash and similar injuries to the neck can disturb the nerves and blood vessels that supply the thyroid, causing the gland to become gradually less efficient.
Oestrogen levels can be related to thyroid function, as it appears oestrogen competes with thyroxine, preventing it from exerting its effect. Many women approaching the menopause, who may have an imbalance of oestrogen, begin to experience symptoms of hypothyroid.
When pregnant, the immune system is depressed, in order to reduce the risk of rejecting the foetus. This may result in the body actually attacking the thyroid. The problem often resolves itself in time, but some women develop long-term hypothyroidism after giving birth.
Thyroxine contains the mineral iodine, which has a similar chemical structure to chlorine and fluorine found in water and toothpaste. These minerals can interfere with iodine metabolism.
Thyroid function can be affected by imbalances in our adrenal or stress glands, often the result of chronic stress, which can cause a high production of adrenal hormones. This has been shown to suppress the production of thyroid hormones and to affect the conversion of T4 to T3.
Stress, illness, nutritional deficiencies and toxic metals, such as lead and mercury, can also affect the conversion of T4 to T3. In other words, circulating levels of thyroid hormones can appear normal, but the body is unable to utilise them efficiently.
Nutritional deficiencies can adversely affect both the production of thyroid hormones and their ease of use by the body.
Thyroxine is composed of the amino acid tyrosine and the mineral iodine. A deficiency of either in the diet can, therefore, lead to low thyroid function. Conversely, an excess of iodine can inactivate the production of thyroid hormones. Iodine is found in seaweed, such as kelp, and seafood. Look for a supplement that contains these important nutrients to support optimal thyroid function.
Vitamin E is involved in the production of TSH, while manganese is necessary for transporting the hormone through the bloodstream.
Selenium, copper and zinc are important for the conversion of T4 to T3, while the metabolism of tyrosine requires vitamins B3, B12, C and E, folic acid and iron.
Goitrogens are foods that contain a substance that can reduce the uptake of iodine by the thyroid. Goitrogenic foods include raw cabbage, cauliflower, broccoli, sprouts, kale, swede, turnip, tapioca, soya, sweetcorn, millet, peanuts, pine nuts, almonds and walnuts. However, these foods only pose a problem when they dominate the diet. Goitrogens are usually inactivated with cooking, so cooked versions are fine.
In order to support your thyroid, make sure you are including plenty of the above nutrients in your diet, as well as eating small, regular meals containing some protein, such as nuts, seeds, fish, poultry, eggs, lentils or beans. This will help to stabilise blood sugar levels.
I normally recommend that patients avoid fluoridated toothpaste, switch to filtered water and practice relaxation techniques, such as yoga, deep breathing exercises, massage and meditation, which can help manage stress.