by Tianyu Tang, M.S. and Sat Bir Singh Khalsa, Ph.D.
Sitting in front of our neck below the Adam’s apple is a butterfly-shaped gland named the thyroid. Small but important, it regulates numerous metabolic processes in our body by producing two main hormones: thyroxine (T4) and triiodothyronine (T3). The function of the thyroid gland is regulated by a feedback mechanism that involves the hypothalamus and the pituitary gland in the brain. When thyroid hormones are low, the hypothalamus produces thyrotropin releasing hormone (TRH), which then signals the pituitary gland to release thyroid stimulating hormone (TSH), causing the thyroid to produce more T4.
Problems with any of the three components of the hypothalamus-pituitary-thyroid (HPT) axis may cause thyroid disorders. Over 12 percent of the total U.S. population will develop a thyroid disease over their lifetime. The two most common thyroid disorders are hypothyroidism (underactive thyroid) and hyperthyroidism (overactive thyroid), which occur in about 5 percent and 1 percent of the U.S. population, respectively, and are most common in women. Hypothyroid symptoms include fatigue, depression, joint and muscle pain, cold intolerance, weight gain, slowed heart rate, and menstrual irregularities.
Common causes include Hashimoto’s disease, an autoimmune disorder, iodine deficiency, thyroid nodules, thyroiditis, and congenital hypothyroidism. The excessive thyroid hormones in hyperthyroidism cause metabolic processes to speed up with symptoms including irritability, trouble sleeping, muscle weakness, heat intolerance,weight loss, diarrhea, rapid heartbeat, and menstrual irregularities. Graves’ disease, another autoimmune disease, is the most common cause, but other causes include thyroid nodules, thyroiditis, and excessive intake of iodine, and thyroid hormones.
Traditional treatments for thyroid disorders are medications or surgery. Hypothyroidism is usually treated with levothyroxine, a hormone replacement medication. Hyperthyroidism is most often treated with antithyroid medicines and beta blockers to manage symptoms. Another common and effective treatment is radioactive iodine, whereas surgery to remove part of the thyroid is the least-used option. People with thyroid disorders sometimes choose complementary and integrative medicine (CIM) to help manage the side effects and anxiety that come with traditional treatments. Some scientists have suggested that yoga and meditation may lead to neuroendocrine changes that affect thyroid function. Werner et al. suggested in the journal Psychosomatic Medicine in 1986, that meditation could affect the secretion of hypothalamic factors and pituitary hormones, leading to more efficient functioning of the HPT axis.
More recently, Singh et al. stated in Complementary Therapies in Clinical Practice in 2011, that yoga is well-suited to the needs of thyroid patients. Specific yoga practices have been recommended for maintaining thyroid gland function and metabolic processes as a complementary therapy. The intricate interplay between stress and thyroid hormones is especially important for autoimmune thyroid disorders, such as Grave’s and Hashimoto’s diseases. These disease symptoms are often worsened due to inflammatory responses triggered by chronic stress. Lifestyle changes, which incorporate strategies to counteract chronic stress suchas physical exercises, diet, restful sleep, and relaxation techniques including deep breathing and yoga, can help in the long-term management of thyroid disorders.
Studies showing the benefit of yoga practice for those with abnormal thyroid conditions have been positive. Maske and Barnwal conducted two consecutive studies in India, which showed yoga to be effective adjunct therapy to medication in treating hyperthyroidism. In their study published in the International Journal of Applied Research, 40 patients with clinical hyperthyroidism were assigned to either yoga practice or control, and both groups were kept on medication for 6 months. After practicing hatha yoga 30-minutes daily for 3 months, participants showed significant improvement in T3 level, whereas the control group experienced no change. In their other study published in the International Journal of Medical and Health Research, 40 female patients with hyperthyroidism were assigned to either yoga or control. After 3 months, participants experienced a significant decrease in T4 level, whereas the control group experienced no change.
Studies have also shown the positive effect of yoga in treating hypothyroidism or its related symptoms. In a study published by Nilakanthan in 2016, 22 women with hypothyroidism underwent 6 months of yoga practice for 1 hour a day, 4 days a week, and continued to take thyroxine during intervention. Measurements post-intervention showed improvement in lipid profile as well as thyroxine medication dosage, despite no significant reduction in serum TSH.
In another study conducted by Banerjee in 2019, 150 women with obesity-induced hypothyroidism experienced improvement in both body weight and TSH level after 45-min daily yoga and diet intervention for 4 months, as opposed toa medication and diet intervention. This study therefore recommended yoga for women in metro cities in India to reduce obesity and hypothyroidism.
A case-study published by Gowda et al. in 2017 reported a 50-year-old man who underwent a tailored yoga and naturopathy intervention, and successfully managed his metabolic syndrome and hypothyroidism. At the end of 6 weeks, he experienced improvements in all physical measures including TSH level, went off medications, and reported better overall health. These positive effects were sustained after 12 weeks, as he continued the prescribed diet and yoga, implying that lifestyle changes are safe and effective interventions.
In a study conducted by Swami et al. in 2009, 20 females with hypothyroidism underwent 6 months of 45-minutes daily pranayama and meditation. Their pulmonary function tests and TSH level were significantly improved. The authors suggested that the changes in pulmonary function may be due to improved respiratory muscle strength and air entry.
In a study conducted by Singh et al. in 2011, 20 female hypothyroid patients reported significantly improved quality of life across all domains using the WHO QoL Scale, after practicing 1-hour daily yoga for 1 month. The study showed that yoga is helpful in managing hypothyroid disease symptoms, such as those related to energy levels, weight changes, physical appearance, and psychological motivation. Studies conducted in populations with normal thyroid functions show mixed results on the effect of yoga on thyroidfunction.
An early prospective study published by Gordon et al. in 2008 investigated the effect of yoga and physical training on 231 patients with Type II diabetes randomized into three groups: yoga, physical training, and control, and found no changes inthyroid hormones in any group over the 6-month period. In a 2018 study published in the Journal of Physical Activity and Hormones, 20 young, healthy women in Iran were randomized into a yoga group, where they practiced hatha yoga 90-minutes daily, 3 timesa week for 8 weeks, and a control group where they continued routine activities. Results showed no effect of yoga intervention on any thyroid hormone levels.
A 2016 study conducted by Chaturvedi et al. in India compared the effect of hatha yoga and physical exercise on a range of biophysical indicators in 216 perimenopausal women. Despite changes in other parameters, TSH levels did not change in either group and did not differ between groups. In another study published in 2017 in India, researchers recruited 50 healthy volunteers to practice yoga 75-minutes daily, 6 days a week for 41 days, and again no change in thyroid function was observed after short-term yoga practice.
On the other hand, two studies have reported TSH reduction with yoga and meditation in populations with normal thyroid functions. In a study by Werner et al., 11 healthy young men with an average of 7 years of meditation practice experienced a continuous decline in TSH level, with no consistent changes in serum T3 or T4 levels over a 3-year period of Transcendental Meditation practice. In a randomized control trial conducted by Rani et al. in India, 126 women of reproductive age with menstrual irregularities underwent either medication plus Yoga Nidra or medication only. They performed yoga for 35-40 min a day, 5 days a week for 6 months. Results showed a significantly higher decrease in TSH level along with other reproductive hormones in the yoga group, compared to the control group, suggesting that Yoga Nidra was helpful in reducing symptoms of menstrual abnormalities and hormone imbalances.
In summary, existing studies have demonstrated the positive effect of yoga and meditation as complementary therapies for thyroid disorders. The benefits are most likely brought about by increased physical activity and relaxation, leading to improved regulation of the HPT axis and better management of disease symptoms. Yoga practice improves the regulation of the psycho-neuro-endocrine and immune systems and results in a more balanced state of health. Future studies that utilize a large sample size, more generalized populations, and randomized study designs are warranted to confirm and extend these findings.
Tianyu Tang grew up in China with a childhood love for singing, dancing, and reading. After gaining a liberal arts education from the U.S., she continued her graduate training in public health and epidemiology with a focus on cancer research. She stumbled across Kundalini Yoga in 2014, and has since found tremendous peace, creativity, and self-expression in this practice. She has worked in private research, international NGO, and academia. Currently she lives in Beijing and is exploring venues for her passion in teaching, writing, and working withchildren.
Sat Bir Singh Khalsa, Ph.D. is the KRI Director of Research, Research Director for the Kripalu Center for Yoga & Health, and Assistant Professor of Medicine at Harvard Medical School. He has practiced a Kundalini Yoga lifestyle since 1973 and is a KRI certified Kundalini Yoga instructor. He has conducted research on yoga for insomnia, stress, anxiety disorders, and yoga in public schools. He is editor in chief of the International Journal of Yoga Therapy andThe Principles and Practice of Yoga in Health Careand author of the Harvard Medical School ebook Your Brain on Yoga.