Wellness Tips

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Other/Organ Health

Thyroid function and dysfunction

In last week's tip I began a mini-series on the endocrine system by trying to explain the role of cortisol in our bodies, and trying to get across the fact that problems with cortisol, either lack of, too much of, or an inappropriate circadian rhythm, can cause a very wide variety of symptoms because of its interaction and effect on our other hormones. Because cortisol is the hormone that is released when we are stressed, and considering we have not evolved very much from the time of primitive man when stressful events were almost always life-threatening, our brains prioritize the role of cortisol over the other hormones. Like I said last week, if you are running from a lion, reproduction, digestion and sleep are not high on the priority list, so why waste the body's resources on those hormones! Same thing in today's modern world, except our "acute lion stress" is now chronic work stress, time stress, relationship stress, chronic pain etc. The body only sees the stress, and figures you don't need much of the other hormones because cortisol is needed now in order to save your life.

But to be healthy and to function well, we DO need those other hormones. For example, the thyroid hormones are in charge of our metabolism or our energy production, which in turn helps regulate our body temperature. Our body chemistry works best at 37 degrees Celsius or 98.6 degrees Fahrenheit, and if the temperature isn't right, enzyme and catalyst activity is compromised.  Pretty important stuff!  We hear of people say they have "sluggish thyroids", and frequently they have difficulty controlling their bodyweight.  Or we say "that person has a high metabolism - they can eat absolutely anything and they won't gain a pound."  People that know me know that I am always cold.  I wear long underwear until about May, and really struggle to stay warm in the winter no matter how many layers of clothes I'm wearing.  I like it hot - 25 to 28 degrees Celsius and I'm happy.  It only occurred to me very recently that maybe I have a thyroid issue. I have a few of the other symptoms - very dry, scaly skin generally, and "chicken skin" on the upper arms and legs (yuck)!  Other symptoms of thyroid problems include  fatigue, depression, osteoporosis, infertility, muscle weakness, too hot, hair loss, memory problems, constipation, inability to sweat, heart-rate disturbances, increased homocysteine and C-reactive protein levels which are both risk factors for heart disease.

The thyroid gland sits on the front of the neck and secretes calcitonin which is needed for calcium absorption into the bones, which is why impaired thyroid function can lead to osteoporosis. The thyroid also secretes thyroxine (T4) at the urging of thyroid stimulating hormone (TSH) which comes from the pituitary gland.  T4, the inactive form, is made up of four iodine molecules.  It goes to the liver, which through liver enzyme activity, converts it into T3 by dropping an iodine molecule.  T3 is the active form of thyroid hormone which regulates metabolism and body temperature.  If for some reason the liver does not have enough of the enzymes needed, Reverse T3, another inactive form of T3 is made. If too little T3 is made, one has hypothyroidism, and if too much is made, one has hyperthyroidism.  Thyroid problems can stem from prioritizing cortisol so T3 does not get made, from inadequate iodine in the diet, or from a liver that is struggling in its detoxification role and can't make the enzymes necessary to convert T4 to T3.  The other halogens like chlorine and fluorine have a higher affinity for the iodine receptors than iodine does, so drinking chlorinated and fluoridated water may be responsible for an inability to absorb iodine, and thereby affect thyroid function. Another important reason to filter our water!  Goitrogens like processed soy and peanuts also block the absorption of iodine.  Omega 6 vegetable oils are usually already rancid when consumed, and the oxidative processes seem to damage enzyme activity, increase inflammation, and block production of thyroid hormone.  Coconut oil, a medium-chain fatty acid seems to aid thyroid function.  Mercury in the body displaces selenium, which is needed to convert T4 to T3.

To diagnose thyroid issues, the doctor must do more than simply measure Thyroid Stimulating Hormone (TSH), as even if TSH is below 2, thyroid problems may exist. Request that your doctor also measure free T3 and free T4 levels, as then it is easier to figure out where in the chain the problem is occurring.  It is quite possible that T3 is low and T4 is normal.  In this case, the body is unable to convert T4 into T3, so the problem may be due to a liver or an adrenal/cortisol issue.  Treating with a drug like Synthroid is completely useless in this scenario, as it only provides T4 and does nothing to aid the conversion into T3.  Taking one's temperature 3, 6 and 9 hours after rising for a few days can also be helpful to your physician in determining thyroid problems.  If you are getting your thyroid checked, to me it makes sense to also run a circadian cortisol test, because treating the thyroid if the cause is poor adrenal function is an exercise in futility.

Much of the info in this tip came from Bev Maya, a medical herbalist in the Vancouver area that practices functional medicine.

Related Tips
How hormones, neurotransmitters and steroids work
Mind and body; psyche and soma
Adrenal Fatigue
Cortisol, our stress hormone
Acute vs. chronic stress
Allopathic vs. functional medicine

Lecture by Bev Maya, Westcoast Women's Clinic, July 11, 2007
O'Reilly, Denis Thyroid function tests - time for reassessment BMJ 2000; 320: 1332-1334.
Wilson, James Adrenal Fatigue, 21st Century Stress Syndrome Smart Publications, Petaluma, CA 2001.
Shoman, Mary Living Well with Hypothyroidism HarperCollins New York, NY. 2000.
Doerge, DR et al. Inactivation of thyroid peroxidase by soy isoflavons, in vitro and in vivo J Chromatogr B Analyt Technol Biomed Life Sci. 2002 Sep 25;777(1-2):269-79.
Canaris, G et al. The Colorado thyroid disease prevalence study Arch Intern Med. 2000 Feb 28;160(4):526-34.
Adrenal and Metabolic Interpretive Guide, Biohealth Diagnositcs Inc. 2006
Chronic Stress - The Number 1 Source of Illness
Chronic Stress Response Chart
Steroidal Hormone Pathway Chart

Copyright 2007 Vreni Gurd