Thyroid Health. Naturopathic Approaches to Strengthening the Thyroid

Transcription

1 Thyroid Health Naturopathic Approaches to Strengthening the Thyroid by Tanya Lee, H.BSc., N.D Bloor St. W, Suite 201 Toronto, ON M6G 1K Health Centre of Milton 420 Main St. E Unit Milton, ON L9T 1P Introduction The thyroid gland is an endocrine organ responsible for metabolism in the body, regulating functions such as energy use, body temperature, and heart rate. The thyroid gland first produces and secretes the hormone thyroxine (T 4 ), generally an inactive hormone, which is then converted to its active form, triiodothyronine (T 3 ). Our pituitary gland secretes a hormone called thyroid stimulating hormone (TSH), which mediates the release of T 4 from the thyroid gland through a negative feedback signal when thyroid hormones are at good levels, this signals the pituitary gland to stop releasing TSH; when thyroid levels are low, the pituitary gland releases TSH in response. Hypothyroidism is a condition where the thyroid gland fails to produce adequate amounts of thyroid hormone. This could be due to a problem with the thyroid gland (primary), the pituitary gland (secondary), or the hypothalamus (tertiary), with primary making up 99% of hypothyroid cases. [1] Hypothyroidism is present in all parts of the world and is the most common endocrine disorder seen by family physicians today. [2] It is typically characterized by symptoms including fatigue, dry, cool skin, constipation, brittle nails, hair loss, and weight gain, but overall, symptoms can be very general and vague. If left untreated, hypothyroidism can lead to enlargement of the thyroid, hoarseness, water retention, and thickening of skin, and can contribute to dyslipidemia, infertility, hypertension, and cognitive impairment. [3] Primary hypothyroidism is generally diagnosed when blood

2 concentrations of thyroid hormone, T 4, is low, and TSH is high. There are a number of causes of hypothyroidism, the most common being thyroiditis, inflammation of the thyroid, caused by autoimmunity, viral infection, medications, birth defects, or pituitary gland defects. [4] Women are more likely to develop hypothyroidism than men, with its incidence increasing with age, especially in those over 50 years of age. [1] Hypothyroidism, however, is not an overnight process, with many people suffering from symptoms of hypothyroidism, but with blood concentrations of thyroid hormone coming back within the normal ranges. Subclinical hypothyroidism (SCH) is a condition where some symptoms of hypothyroidism are present and TSH is read high, but T 3 and T 4 concentrations are within normal range. The prevalence of SCH in the general population is 4 8%, [5] and SCH can progress to overt hypothyroidism in 2 4% of the cases annually. [1] TSH is therefore the hormone used to diagnose and monitor treatment of subclinical hypothyroidism. Currently, most Canadian laboratories set TSH range between mu/l, but it is routine practice not to treat SCH until TSH measures about 10 mu/l. [6] It is general practice for most forward-thinking clinicians to screen for SCH in patients within this range lowering this upper limit as part of a screening process in those experiencing hypothyroid symptoms can guide clinicians to start supportive treatment in order to avoid progression to overt hypothyroidism. [7, 8] Not only do those with SCH experience symptoms of hypothyroidism, but has also been found to be at increased risk of other metabolic diseases, such as cardiovascular disease and infertility/pregnancy loss. [9, 10] Current treatment for hypothyroidism is treating with a synthetic version of T 4 (thyroxin or levothyroxin). [2] This treatment is extremely effective in stabilizing the overt hormone imbalance found in hypothyroidism with minimal side effects, stabilizing TSH and T 4 blood concentrations. However, many clinicians report that patients, although they feel better while on the therapy, still feel symptoms of hypothyroidism, despite the stabilization of hormone levels. Naturopathic Approaches to Hypothyroid Symptoms In clinical practice, it is imperative for naturopathic doctors to be able to catch symptoms of suboptimal thyroid function. From there, a treatment can be recommended that will stabilize and optimize thyroid function which does not involve hormone replacement. By optimizing thyroid function before it reaches

3 hypothyroid state, we may be able to avoid the use of hormone replacement therapies, as well as improve day-to-day symptoms of suboptimal thyroid function. There are a number of naturopathic treatments that also work synergistically with T 4 replacement, improving its function and helping to relieve symptoms at the lowest dose possible. Minerals In order T 4 to be optimally converted to T 3, it must go through a series of chemical reactions. These chemical reactions utilize minerals to drive these reactions, primarily iodine and selenium. Iodine is a mineral that is taken up by thyroid cells and serves as a backbone for thyroid hormone production. Iodine is incorporated into thyroid proteins, which go through a series of reactions to create T 4 and T 3. Therefore thyroid hormone synthesis cannot happen if there is no iodine to utilize. Iodine deficiency has been found to be a major cause of hypothyroidism and subclinical hypothyroidism, and has been found to be climbing rapidly in developing countries. [11, 12] A recent study had found that prophylactic iodine supplementation in children with subclinical hypothyroidism improved overall metabolic health. [13] Another study found that administration of iodine in the form of powdered kelp restored thyroid function and urinary iodine concentrations. [11] Iodine is not made by the body, so it is imperative that we take in foods that are rich in iodine in order to achieve optimal iodine status. The recommended daily intake of iodine is 150 mcg daily in healthy adults. Foods that are rich in iodine include seafood (seaweeds like kelp and dulce), and fortified foods such as salt, dairy, and bread, though these may not be the healthiest choices. [13] If diet is not rich in these foods, then supplementation for those who experience hypothyroid symptom is recommended. However, it is important to consult with a health-care practitioner who is educated in iodine dosing, as excessive intake has been found to exacerbate symptoms of hyperthyroidism. Selenium is a mineral that is greatly utilized by the thyroid gland. Selenium is used by thyroid enzymes involved in the conversion of T 4 to T 3, mainly glutathione peroxidase, thioredoxin, and all three iodothyronine de iodinases. Selenium is also an antioxidant which protects the thyroid from damage by free radicals such as hydrogen peroxide, which are produced during the conversion of T 4 to T 3. Selenium deficiency can lead to poor functioning of the thyroid, as the lack of selenium will slow down the function of these

4 enzymes; this can eventually lead to chronic issues of the thyroid, such as inflammation, and eventually the production of autoimmune antibodies. Selenium deficiency has also been linked to worsening iodine deficiency. [14] A recent study found that adults with SCH responded favorably to selenium supplementation, with TSH decreasing by 31% compared to subjects not receiving selenium supplementation. [15] Selenium supplementation also seems to work more favorably in those with hypothyroidism due to autoimmunity. [15, 16] Rich sources of selenium include seafoods such as fish, scallops, and shrimp, as well as mushrooms, asparagus, mustard seeds, and meat products, particularly turkey, lamb, chicken, and beef. The current recommended daily intake of selenium is 55 mcg/d for adults, with toxic doses being difficult to ingest daily. [17] Studies have found supplementation of iodine and selenium can optimize thyroid function. A study performed in 2000 found that supplementation of iodine in children with thyroid goiters and selenium deficiency decreased the size of the goiter and optimized levels of TSH after 50 weeks of treatment. This study also found that the more depleted the children were in selenium, the less responsive they were to iodine supplementation. [18] This shows that concomitant supplementation with selenium may improve and optimize iodine supplementation. Exercise and Herbs Exercise is important for maintaining good health in every individual. In those with hypothyroidism or SCH, exercise becomes even more important in order to counteract the effects of slower metabolism in those affected this can help prevent and improve metabolic diseases associated with hypothyroidism and SCH such as obesity and cardiovascular disease. [19] It is recommended that those with hypothyroidism or SCH participate in invigorating, heart rate accelerating activities in order to maintain optimal metabolic rate, especially in those who are dieting. [20] Fucus vesiculosis (bladderwrack) is a seaweed found on the coasts of the Atlantic and Pacific oceans. Though it has not been extensively researched on its direct effect on the thyroid, it has been traditionally used to treat goiter due to its high iodine content. The British Herbal Pharmacopoeia advocates for the use of Fucus vesiculosis for thyroid condition for its ability to stimulate T 4 production and improve basal metabolic rate, due to its high, bioavailable iodine content. [20]

5 Withania somnifera (ashwagandha) is a flowering plant belonging to the Solanaceae family, mainly found in Africa and the Middle East, and is a staple herb in Ayurvedic medicine. It has been traditionally used as an adaptogen and tonic, improving muscular energy, recovery from illness, and promoting the growth of children. [20] The effect of Withania on the thyroid has been represented in animal studies, where the root extract has been found to increase serum concentrations of T 4 in female mice after 20 days. [21] Discussion Hypothyroidism is a condition that is prevalent in many parts of the world and can lead to generalized symptoms that many people can feel on a daily basis. Overt hypothyroidism can be detected through routine blood tests and is treated by replenishing T 4 through a synthetic derivative. However, it is important to understand that subclinical hypothyroidism is also a prevalent condition and, if left untreated, can lead to overt hypothyroidism, and can also lead to metabolic and hormonal conditions such as cardiovascular disease and infertility. Due to the health impacts of SCH, it is important to seek out a medical professional who practices well-researched screening protocols for thyroid disorders, especially if symptoms are present, despite normal blood levels of thyroid hormones. If SCH is diagnosed early enough, they could avoid progression to overt hypothyroidism through treatments which optimize thyroid function. Naturopathic treatments such as mineral supplementation and medicinal herbs, as well as exercise, can help one experience relief of hypothyroid symptoms and restore optimal functioning of the thyroid gland. References 1. Khandelwal, D., et.al. Overt and subclinical hypothyroidism: who to treat and how. Drugs Vol. 72, No. 1 (2012): Qari, F. Hypothyroidism in clinical practice. Journal of Family Medicine and Primary Care Vol. 3, No. 2 (2014): Gaitonde, D., et. al. Hypothyroidism: an update. American Family Physician Vol. 86, No. 3 (2012): A.D.A.M Medical Encyclopedia. Bronchitis - acute. Reviewed Accessed Muller, A.F., et al. Thyroid function disorders Guidelines of the Netherlands Association of Internal Medicine. The Netherlands Journal of Medicine Vol. 66, No. 3 (2008): British Columbia Ministry of Health. Thyroid Function Tests in the Diagnosis and Monitoring of Adults thyroid.html Reviewed Accessed Andersen, S., et. al. Narrow individual variations in serum T 4 and T 3 in normal subjects: a clue to the understanding of subclinical thyroid disease. The Journal of Clinical Endocrinology and Metabolism Vol. 87, No. 3 (2002): Eastman, C.J. Screening for thyroid disease and iodine deficiency. Pathology. Vol. 44, No. 2 (2012): Duntas, L.H., et. al. Cardiovascular risk and subclinical hypothyroidism: focus on lipids and new emerging risk factors. What is the evidence? Thyroid Vol. 17, No. 11 (2007): Khalid, A., C. Joyce, and K. O Donoghue. Prevalence of subclinical and undiagnosed overt hypothyroidism in a pregnancy loss clinic. Irish Medical Journal Vol. 106, No. 4 (2013): Takeuchi, T., et. al. Treatment of hypothyroidism due to iodine deficiency using daily powdered kelp in patients receiving long-term total enteral nutrition. Clin Pediatr Endocrinol. Vol. 20, No. 3 (2011): Zimmermann, M.B., et. al. Iodine treatment in children with subclinical hypothyroidism due to chronic iodine deficiency decreases thyrotropin and C peptide concentrations and improves the lipid profile. Thyroid Vol. 19, No. 10 (2009): Leung, A.M., et. al. Consequences of excess iodine. Nature Reviews. Endocrinology Vol. 10, No. 3 (2014):

6 14. Kvícala, J., et. al. Correlations between parameters of body selenium status and peripheral thyroid parameters in the low selenium region. The Analyst Vol. 120, No. 3 (1995): Nordio, M., et. al. Combined treatment with myo-inositol and selenium ensures euthyroidism in subclinical hypothyroidism patients with autoimmune thyroiditis. Journal of Thyroid Research Vol (2013): Köhrle, J. Selenium and the thyroid. Current Opinion in Endocrinology, Diabetes, and Obesity Vol. 20, No. 5 (2013): The George Mateljan Foundation. Selenium. The World s Healthiest Foods Reviewed 2014 Accessed Zimmermann, M., et. al. Effect of oral iodized oil on thyroid size and thyroid hormone metabolism in children with concurrent selenium and iodine deficiency. European Journal of Clinical Nutrition Vol. 54, No. 3 (2000): Garces-Arteaga, A., et. al. Influence of a medium-impact exercise program on health-related quality of life and cardiorespiratory fitness in females with subclinical hypothyroidism: an open-label pilot study. Journal of Thyroid Research Vol (2013): Hechtman, L. Clinical Naturopathic Medicine, Revised ed. Australia: Elsevier, Panda, S., et. al. Withania somnifera and Bauhinia purpurea in the regulation of circulating thyroid hormone concentrations in female mice. Journal of Ethnopharmacology Vol. 67, No. 2 (1999):