Do you find yourself eating healthy, exercising regularly only to not see the slightest shift on the scale? It could most likely be due to a little troublemaker known as your thyroid.
Where does it all start?
The thyroid gland is part of the endocrine system. It is a small bow-shaped gland, located in the front of the neck, below the voice box or larynx (Adam’s apple). It is important as it plays a vital role in supporting numerous body functions such as controlling body temperature, metabolic rate (the rate at which the body burn calories from the food we eat) and energy levels.
The gland is controlled by the hypothalamus and pituitary gland at the base of the brain. The pituitary produce thyroid stimulating hormone (TSH) that travels through the blood to stimulate the production of the thyroid hormones called thyroxine (T4) and triiodothyronine (T3). The thyroid gland uses iodine from our diet to produce these hormones.
The most common thyroid disorder is hypothyroidism or an underactive thyroid function. Hypothyroidism is usually caused by an autoimmune response known as Hashimoto's disease or autoimmune thyroiditis.
As with all autoimmune diseases, the body mistakenly identifies its own tissues as an invader and attacks them until the organ is destroyed. This chronic attack eventually prevents the thyroid from producing adequate levels of T3 and T4, which are necessary to keep the body functioning properly.
The lack of these hormones can slow down the metabolism and cause weight gain, fatigue, dry skin and hair. Hyperthyroidism or an overactive thyroid function is another common thyroid condition. The most prevalent form is Graves' disease in which the body’s autoimmune response causes the thyroid gland to produce too much T3 and T4. Symptoms of hyperthyroidism can include weight loss, high blood pressure, diarrhoea and rapid heartbeat.
How can nutrition help regulate your thyroid?
Many nutrients play a role in optimising thyroid function. However, both nutrient deficiencies and excesses can trigger or exacerbate symptoms.
Working in collaboration with an endocrinologist is vital to determine thyroid function and obtain the best treatment possible. A dietitian is the person to guide you towards selecting the correct type of foods for optimal thyroid health.
Note: If you have hypothyroidism, you will need to take thyroid hormone replacement medication – usually on an empty stomach as certain foods and supplements may interact with the medication.
Selenium is a necessary component of the enzymes responsible for converting T4 into T3, and without adequate levels of selenium there would be no activation of thyroid hormone. Some researchers suggest that selenium supplementation will improve conversion of T4 to T3, and in some trials a dosage of 200 mcg per day has been found to reduce thyroid antibodies.
Some other studies have shown that selenium caused a reduction of the antibodies by 50% over the course of three months. Selenium also plays a role in protecting the thyroid gland itself. The cells of the thyroid generate hydrogen peroxide to produce thyroid hormones, and selenium protects the thyroid gland from the oxidative damage caused by these reactions.
Selenium balances iodine, as too high iodine levels lead to destruction of the thyroid cells. It is important to include selenium-rich foods daily into your diet such as brazil nuts, canned tuna, fatty fish such as salmon, mackerel, pilchards, sardines etc.
Should I avoid soya?
Soya does not have to be avoided as according to research one can safely consume soy foods, especially if daily iodine intake is adequate. Studies have indicated that phytoestrogens in soybeans and soy-rich foods may inhibit the activity of an enzyme that makes thyroid hormones. It is therefore important that soy should always be consumed after taking thyroxin medication to prevent any possible interactions.
Goitrogens? Say what?
Many websites claim that people with thyroid disorders should avoid cruciferous vegetables like cabbage, kale, Brussels sprouts, broccoli and cauliflower. This is because they contain natural chemicals called goitrogens (producing goitres) that could interfere with thyroid hormone production. The risk however is low if you are consuming these types of vegetables in moderation. It is also recommended that you cook or steam the vegetables as it deactivates the goitrogens.
Adequate vitamin D levels have been associated with a lower likelihood of developing Hashimoto’s. Vitamin D levels should be checked at regular intervals. Research shows that blood levels of 25-hydroxyvitamin D [25(OH)D] should be between 60-80ng/l for optimal thyroid receptor and immune system function. Sources of Vitamin D include cod liver oil, fatty fish, fortified dairy, eggs and sunlight. Despite dietary interventions and sunlight, many people may still require an oral vitamin D3 supplement to reach their target levels.
What about a gluten free diet?
To date, no studies have evaluated the effects of a gluten free diet in people who have autoimmune thyroid disease (ATD). This remains an area of controversy, as the results are inconsistent. A gluten free diet is advisable only for patients with co-existing coeliac disease or gluten intolerance. It is suggested that if you are interested in trying a gluten free diet, you should be tested for coeliac disease before going gluten free, even in the absence of gastrointestinal symptoms. Once a gluten free diet is adopted, the autoimmune markers for the disease disappear, so it is critical that the testing precedes dietary changes to insure accuracy. If, however, the test is negative, a trial gluten free diet emphasising naturally gluten free foods (for example, fruits and vegetables, pulses, quinoa, corn, rice, nuts, seeds, fish, chicken, red meat) followed for several months will allow you to observe potential benefits.
If you’re interested in checking your thyroid, you can get the whole picture by asking your endocrinologist to look at all of these levels: TSH, Free T4, Free T3, Reverse T3, and Thyroid Antibodies & Vitamin D.
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