Why Screening and Commonly Prescribed Thyroid Drugs Often Fail to Relieve Symptoms

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May 31, 2017 | 41,923 views

Story at-a-glance

  • Thyroid hormones influence nearly every cell in your body, regulating metabolism, growth and affecting the development of fibromyalgia, autoimmune disorders and irritable bowel syndrome
  • The U.S. Preventive Services Task Force recommends avoiding screening for thyroid cancer as it often leads to dramatic treatments for cancers that would not have developed into life-threatening tumors
  • Suboptimal thyroid function may be a result of exposure to environmental toxins, such as fluoride and flame-retardant chemicals; your thyroid function may be supported using easily integrated strategies

By Dr. Mercola

Your thyroid gland, located in the front of your neck, influences almost every cell in your body. Thyroid hormones regulate your metabolism, and are required for growth and development in children and nearly every physiological process in your body.

When your thyroid levels are unbalanced, it can spell trouble for your overall health and wellness. Evidence suggests nearly 60 percent of people with suboptimal thyroid function are unaware of their condition.1 While prevalent, it is often easily treatable and may reverse symptoms of other health conditions.

Poor thyroid function is linked to health conditions such as fibromyalgia, irritable bowel syndrome, eczema, gum disease and autoimmune disorders. Symptoms of low function and the health conditions affected by low levels are varied, as the hormone is used throughout your body.

Women are five to eight times more likely than men to have low thyroid function and 1 in 8 women will develop a thyroid disorder in her lifetime.2 Understanding the basics of how your thyroid functions and what may cause a dysfunction is important to your overall health.

Thyroid Function

Your thyroid gland is shaped like a butterfly on your neck just under your voice box and secretes four hormones: T1, T2, T3 and T4. The number indicates the number of molecules of iodide attached to the hormone. These hormones interact with other hormones, such as insulin, cortisol and sex hormones.

Your hypothalamus secretes thyrotropin-releasing hormone (TRH) that triggers the pituitary gland to release thyroid stimulating hormone (TSH) that then causes your thyroid to release T4. Almost 90 percent of your thyroid hormone is released in an inactive form of T4. Your liver then converts T4 to T3 with the help of an enzyme. T2 is currently the least understood form of thyroid hormone and is the subject of a number of ongoing studies.

When everything is working properly, your body makes enough T4 that is converted to T3 to control the metabolism of every cell in your body. T3 is critical in the communication of messages to your DNA to increase your metabolism by burning fat. In this way, it helps keep you lean. Nutritional imbalances, toxic exposures, allergens, infections and stress can disrupt this hormonal balance, leading to a series of health complications including hypothyroidism, hyperthyroidism and thyroid cancer.

Thyroid Cancer Acts Differently Than Other Cancers

You may have been swayed by advertisements from an industry-funded foundation3 to be screened for thyroid cancer, but the U.S. Preventive Services Task Force has added this screening process to their "don't-do-it category" in recommendations published in the Journal of the American Medical Association.4

The task force believes the consequences of thyroid cancer screening far outweigh the benefits. Although most cancer screenings help detect early disease and increase the potential for successful treatment, in this case early screening may actually backfire.

In many cases thyroid cancer screening will yield a false positive result, finding cancers that would never grow into life-threatening tumors.5 However, once discovered, most physicians feel obligated to recommend treatment, which often includes removal of the thyroid gland, and which may have significant side effects.

Surgeons may accidently sever nerves that control speech and swallowing, or remove the parathyroid gland that regulates calcium levels in your body. In an accompanying editorial, Dr. H. Gilbert Welch, of Dartmouth Institute for Health Policy and Clinical Practice, discussed problems with overdiagnosis of thyroid cancer.

Data from the SEER program demonstrated the incidence of thyroid cancer had remained relatively stable until 1990, after which it tripled.6 However, more interesting is that despite this rapid increase, mortality from thyroid cancer has remained stable, an indication cancers are identified and treated that don't require treatment. Welch said:7

"Patients with newly diagnosed thyroid cancer typically have been treated aggressively. As of 2013 in the United States, over 80 percent underwent total thyroidectomy and subsequently required lifelong thyroid replacement therapy."

Do You Have Underactive Thyroid Function?

This is a requirement for normal thyroid hormone function. In this video Dr. Jorge Flechas discusses the rampant iodine deficiency that plagues industrialized nations and the doses that may be necessary to reverse this trend.

Avoid sources of bromine

Bromine appears to play a large role in the rising number of people suffering from iodine insufficiency. Bromines are found in pesticides, plastics, baked goods, soft drinks and fire retardants.

Vitamins and amino acids

Vitamins B1227 and A28 with amino acid tyrosine29 have demonstrated beneficial effects in people who suffer from suboptimal thyroid function.


This is an extract of the sap from an Indian myrrh tree, which enhances the conversion of T4 to T3 in your body.30 Traditionally, the supplement was used to treat low metabolism, a symptom of suboptimal thyroid function. In an animal model, researchers found rats given guggul had increased uptake of iodine from their food and increased activity of thyroid enzymes with increased oxygen consumption.31

The supplement also demonstrated increased blood concentration of T3 hormone from T4 conversion,32 and increased the activity of the enzyme responsible for converting T4 to T3.33 It is likely unsafe during pregnancy and you should thoroughly evaluate the interactions with your physician before using it.34

Korean ginseng

This is an adaptogen like ashwagandha and contains properties that block production of excessive amounts of reverse T3 (rT3). Asian practitioners developed a fermented ginseng preparation that was absorbed better, faster and stayed in your body longer.35

A human study looked at the impact of this preparation on thyroid hormone levels and found that treatment by injection resulted in better clinical outcomes, healthy increase of T3 and T4 levels and a reduction in rT3.36

[+]Sources and References [-]Sources and References

  • 1, 2 American Thyroid Association, Prevalence and Impact of Thyroid Disease
  • 3 Light of Life Foundation, Sponsors and Partners
  • 4 Journal of the American Medical Association 2017; 317(18):1882
  • 5 NPR, May 9, 2017
  • 6, 7 Journal of the American Medical Association, May 9, 2017, Cancer Screening, Overdiagnosis and Regulatory Capture
  • 8 New England Journal of Medicine, April 3, 2017 Thyroid Hormone Therapy for Older Adults with Subclinical Hypothyroidism
  • 9 QuinteilesIMS Medicines Use and Spending in the U.S. – A Review of 2015 and Outlook to 2020
  • 10 Journal of the American Medical Association, 2016;176(4):473
  • 11 New York Times, April 21, 2017
  • 12 Medicine Net, April 11, 2017
  • 13 KAWC, May 18, 2017
  • 14 Endocrine Web, How Your Thyroid Works
  • 15 Research Gate, C. Loren Buck
  • 16 Organic Chemistry Portal, Finkelstein Reaction
  • 17 Newsweek February 24, 2015
  • 18, 19 WebMD, February 25, 2015
  • 20 U.S. Environmental Protection Agency, Questions and Answers on Fluoride
  • 21, 22 Thyromate, August 3, 2016
  • 23 Global Healing Center, February 27, 2015
  • 24, 25 Very Well, April 20, 2017
  • 26 New England Journal of Medicine, 1999; 340:424
  • 27 American Journal of the Medical Sciences 2006;332(3):119
  • 28 Journal of the American College of Nutrition 2012; 31(4):268
  • 29 University of Connecticut Health Center, Thyroid Hormone Synthesis
  • 30 Life Extension Do You Suffer from Suboptimal Thyroid Function?
  • 31 Planta Medica, 1984;50(1):78
  • 32 Life Sciences, 1999; 65(12): PL137
  • 33 Phytotherapy Research 2005 Jan;19(1):78-80
  • 34 WebMD, Guggul
  • 35 Journal of Ethnopharmacology 2012 Jan 31;139(2):664-7
  • 36 Zhongguo Zhong Xi Yi Jie He Za Zhi. 1999 Apr;19(4):209-11