Thyroid dogma under siege
Hypothyroidism is one of the most common conditions in the United States. No one really seems to understand why there is such an epidemic of underactive thyroid function.
Some chalk it up to normal aging or genetics. Others blame it on as-yet-unidentified environmental factors such as infection or toxins.
Regardless of the cause, most doctors have been taught for decades that the diagnosis and treatment of hypothyroidism is straightforward. A blood test for thyroid stimulating hormone (TSH) determines whether the body is trying to make more thyroid hormone. Elevated TSH indicates that the thyroid gland is not making enough. In such cases most doctors prescribe synthetic thyroid replacement hormone (levothyroxine, also sold as Synthroid, Tirosint and Unithroid).
Many patients respond well to such treatment, but some continue to have hypothyroid symptoms such as fatigue, depression, brain fog, weakness, dry skin, constipation and inability to lose weight despite treatment with levothyroxine (aka T4). They may be told that their lab tests are normal. The doctor may conclude that these complaints are psychological and such patients need to see a psychologist or take an antidepressant.
Despite the conventional dogma that patients with underactive thyroids need treatment with T4 alone, there is growing resistance to this concept. Some physicians point out that the healthy thyroid gland produces small amounts of T3 hormone (triiodothyronine) as well as T4. It is actually T3 that is active in tissues throughout the body, regulating energy use. Although muscles and organs in people with healthy thyroid activity are able to convert T4 to active T3, this may not be the case for everyone.
That’s why some physicians prescribe desiccated (dried) thyroid extract from pigs. This natural medication contains both T4 and T3.
A recent study at Walter Reed National Military Medical Center produced some intriguing results (Journal of Clinical Endocrinology & Metabolism, May, 2013). This is the first randomized controlled trial comparing Armour Thyroid to Synthroid. Almost half of the subjects preferred the extract containing both T3 and T4. They lost more weight (4 pounds on average), felt better and even scored better on a cognitive test.