Dr. Laura: How does your thyroid function?

Feeling tired, loosing hair, bring fog, brittle nails, constipated,  periods heavy and cholesterol rising? Perhaps your thyroid is to blame.

What does thyroid hormone do?

Thyroid hormone keeps:

  • our metabolism humming
  • hair and skin smooth and silky
  • muscles and tendons well lubricated
  • mood bright
  • digestion moving along
  • brain firing on al cylinders
  • LDL cholesterol at healthy levels

How do you measure thyroid function?

General practitioners assess Thyroid Stimulating Hormone (TSH), and if it is out of range, T4 and T3 is measured. Sometimes an ultrasound is done to visualize the size and health of the gland, to assess nodules or help diagnose thyroid cancer.  Naturopathic doctors, functional medicine doctors and endocrinologists will be more likely the ones to run a full thyroid panel (freeT4, freeT3, TSH, TPO, Anti-Thyroglobulin and reverse T3).

How does the body naturally balance thyroid hormone?

T3 is the active hormone in the body and is made from T4. Although the T4 is made in the thyroid, conversion to T3 happens mostly in the liver and the gastrointestinal tract.   A normal functioning thyroid gland works with the hypothalamus in the brain using a negative feedback system to indicate when there is enough active thyroid hormone in the system.

How does the medical doctor balance thyroid?

Traditionally synthroid or levothyroxine is prescribed to treat inadequate levels of thyroid hormone and treatment is geared to reach a desired TSH level. Direct T3 therapy (Cytomel) is rarely prescribed due to lack of research and clinical experience. Typically the family doctor will  treat to normalize the TSH, but recent research, and numerous patient complaints may indicate that this is not enough.

More research is required to support T4 and T3 combination therapy, whether it is levothyroxine plus cytomel or natural desiccated thyroid, alone or in combination.

Research finds TSH monitoring is not enough to determine adequate thyroid functioning and some medical doctors agree a 4:1 ratio of T4:T3 predicts patient satisfaction and better health.

What does the naturopathic doctor do to balance the thyroid?

Naturopathic doctors seek to support the thyroid in making T4 and the body’s ability to convert the T4 to the active form of thyroid known as T3.   A naturopathic doctor offers support to people on pharmaceuticals like synthroid or levothyroxine, and is also able to additionally or solely prescribe advice for nutraceutical  support and natural desiccated thyroid.

A naturopathic doctor will:

  • look at the full thyroid panel
  • adrenal health
  • cholesterol panel
  • sex hormone health
  • the function of the liver
  • health of gastrointestinal tract,
  • nutrient balance of things like selenium, zinc, iron and iodine

How is cholesterol linked to thyroid function?

T3 levels are also inversely linked to LDL Cholesterol. When thyroid levels are low, LDL cellular reception is reduced, leaving more LDL in the blood stream.  Emerging research finds treatment with T4 alone (synthroid, levothyroxine) does not always correct the high levels of cholesterol induced by poor thyroid function. Rising levels of LDL cholesterol in peri-menopausal women with symptoms of fatigue should trigger an investigation into the balance of T4 and T3, not just TSH.

What drives T3 levels down?

  • Body shuttles T3 to reverse T3 in times of starvation and stress
  • Poor feedback function in the hypothalamus
  • Thyroiditis
  • High levels of natural and environmental estrogens
  • Epstein Barr Virus

T3 levels are increasingly challenged as xenoestrogens (environmental contaminants) rise in developed countries.  Peri-menopausal women also experience challenges. This is because estrogen (unopposed by progesterone as ovulation slows down), or estrogen mimickers like xenoestrogens (from plastics, pesticides and insecticides) have the ability to bind up Thyroid Binding Globulin and somehow affect the T4 to T3 conversion ratio. Some research points to Epstein Barr Virus impacting the genome and ultimately the function of the thyroid.

For more help optimizing your thyroid function, book an appointment with Dr. Laura M. Brown, ND.