|The Benefits of Whole |
When it comes to thyroid therapy, nature’s product beats synthetic drugs
By Dr. Edward R. Rosick
First appeared in the January 2004 issue
. . . the results [of whole thyroid], as a rule, are most astounding—unparalleled by anything in the whole of curative measures.
— Sir William Osler
Principles and Practice of Medicine, 1898
he pharmaceutical options available to doctors of today are certainly different from those available to their peers of just a hundred years ago. It seems that new drugs are being introduced every day, and most people assume that these new drugs are better than the old ones. But what if that’s not always true? Are some older medications being driven off the store shelves and the pages of medical journals for economic reasons rather than new scientific evidence? In the case of thyroid hormone replacement therapy, some physicians—especially those who tend to have a holistic medical philosophy—would say yes.
Fortunately for us, the human body is a redundant system in many ways: we have two arms, two legs, two lungs, two kidneys, etc. However, we have only one thyroid gland, and we’d better watch carefully for any sign of thyroid trouble, because this small, bowtie-shaped organ found just below the larynx has profound and wide-ranging effects on our health.
Thyroid Hormones—Vital to Health, and Life Itself
The thyroid gland exerts its powerful actions through at least four hormones, two of which—thyroxine (T4) and triiodothyronine (T3)—are predominant. Two other hormones (appropriately called T1 and T2) are known to be secreted by the thyroid gland, but their functions are not yet clear. The secretion of thyroid hormones is controlled, via a biochemical feedback loop, by the pituitary gland and a hormone it secretes known as thyroid-stimulating hormone, or TSH. If the pituitary detects low levels of thyroid hormones in the bloodstream, it secretes more TSH, which stimulates the thyroid to increase its output.
Although this output consists mainly of T4, the more physiologically active thyroid hormone is actually T3, about 80% of which is produced by conversion from T4 in the liver and other organs (the other 20% is produced by the thyroid gland itself). T3 plays a central role in regulating normal growth and development in infancy and childhood, as well as regulating the body’s energy metabolism throughout life. In terms of overall physiology, the thyroid hormones affect everything from your weight and mood to your cholesterol levels and heart function. Without thyroid hormones, you would not just feel bad—you would die.
Hypothyroidism Can Be Overlooked but Is Easy to Treat
With merely subnormal levels of thyroid hormones, however—a disease called hypothyroidism (or just “low thyroid”)—you could still feel pretty bad. The most common symptoms are dry skin, fatigue, dulling of mental faculties, depression, weight gain, constipation, aching joints, low blood pressure, high cholesterol, low libido, brittle nails, hair loss, and sensitivity to cold. Most cases of hypothyroidism, it is believed, go undiagnosed because the symptoms can so easily be ignored, regarded as normal aspects of aging, attributed to something else, or not even noticed because they develop so slowly and subtly. In a word, they’re ambiguous.
What’s even worse is that hypothyroidism predisposes the patient to more serious disorders, such as heart disease, in part through its cholesterol-elevating effect. The good news, though, is that low thyroid is easy to treat by administering thyroid hormones, preferably in the form of whole natural thyroid. The virtue in this approach is that whole thyroid, by definition, contains all the hormones produced naturally by the thyroid gland, in their biologically normal proportions. Since the actions of all these hormones and their interrelationships with each other and with other bodily systems are not fully understood, it’s reasonable to think that providing all of them is preferable to providing just one (T4), as is customary in modern medical practice.
Subclinical Hypothyroidism Can Be Very Subtle
A problem that has been described in the medical literature for over a century yet is still being debated today is subclinical hypothyroidism. As the word subclinical implies, this is a form of hypothyroidism that does not manifest itself clinically. For one thing, the lab tests for thyroid hormone levels are normal (although typically near the lower end of the normal range). The giveaway that something is amiss, however, is that the individual’s TSH levels are elevated, indicating a greater than normal need for more thyroid hormones.
But what about symptoms? The traditional view has been that, by the very definition of the word subclinical, there are no symptoms with this disorder. Indeed, many people with subclinical hypothyroidism, as determined by the lab tests, feel fine and have no symptoms. Others do have symptoms, however, although most of the symptoms can so easily arise from other causes, or from no apparent cause at all, that it’s often difficult, at least without the TSH test, to ascribe them reliably to subclinical hypothyroidism.
Subclinical Hypothyroidism—To Treat or
Not to Treat?
In any case, subclinical hypothyroidism is believed to have an overall incidence of 4–10% in the general population and 7–26% in the elderly population; it’s especially common in elderly women. Despite the prevalence of this condition, however, there are still physicians who believe that treating it is a waste of time. In fact, a recent, widely cited paper by researchers at the Stanford University School of Medicine was provocatively entitled, “The Treatment of Subclinical Hypothyroidism Is Seldom Necessary.” (To be fair and balanced, however, the journal printed an opposing point of view back-to-back with this paper.)
One of the reasons cited for believing that this is a disease not in search of a treatment is the ambiguous nature of its symptoms. And it’s true that people with normal thyroid function often have similar complaints, especially as they grow older. Yet there have been studies (see the sidebar) showing that people with subclinical hypothyroidism experience these symptoms at a significantly greater rate than those who do not have the condition. Furthermore, recent studies have shown that people with subclinical hypothyroidism have a greater incidence of peripheral arterial disease, hyperlipidemia and coronary artery disease, and musculoskeletal disorders.
Subclinical Hypothyroidism Should Be Treated
Mainstream physicians who believe that subclinical hypothyroidism does not need treatment often state that there have been no large-scale studies that would justify such treatment. The fact is, however, that there have been several large-scale studies showing that people with subclinical hypothyroidism suffer from a myriad of symptoms.
One of the largest such studies, the Colorado Thyroid Disease Prevalence Study, measured serum TSH levels and conducted symptom surveys in over 25,000 Colorado residents. The 2336 people diagnosed with subclinical hypothyroidism reported, significantly more often than people without this condition, that they had the following symptoms: dry skin (28%), poor memory (24%), slow thinking (22%), muscle weakness (22%), fatigue (18%), muscle cramps (17%), cold intolerance (15%), constipation (8%), and hoarseness (7%). This and other similar studies should lay to rest any controversy over the potentially debilitating effects of subclinical hypothyroidism and the need for prompt and proper treatment.
- Carnaris GJ et al. The Colorado Thyroid Disease Prevalence Study. Arch Int Med 2000;160:526-34.
A Capsule History of the Thyroid
Galen, the famed physician of ancient Rome, was one of the first people in the Western world to describe the thyroid gland. It took another 1700 years, however, for scientists to understand the thyroid’s function. In 1888, at a meeting of the Clinical Society of London, a paper was presented that finally described the deleterious effects of a nonfunctioning thyroid gland on the human body and mind.
With this new knowledge, it wasn’t long before physicians began to use thyroid extracts from animals to treat their hypothyroid patients. The first reported case was described in the British Medical Journal of October 10, 1891. The patient was a 46-year-old woman in Newcastle, England, with a severe case of hypothyroidism. Her physician injected her with a glycerin extract of sheep thyroid gland and reported rapid and significant improvement in her symptoms. It’s interesting to note that this one case of a single patient, with no randomized, controlled study to back it up, highlighted a specific and extremely effective therapy for hypothyroidism that was soon taken up by almost the entire medical community in the Western world. (That was a much simpler time.)
Thyroid injections proved to be painful and unpleasant, however, and by 1892, doctors were using desiccated thyroid gland (i.e., a dried and powdered form), generally from cows, sheep, or pigs, to treat the disorder. An examination of the medical literature from the 1920s to the 1970s shows that whole natural thyroid proved, by the tests of both science and time, to be a safe and effective treatment for a number of related conditions, including menstrual irregularities, hypercholesterolemia, and symptomatic atherosclerosis.
The use of whole natural thyroid was accepted and practiced by physicians for over 80 years, yet by 1975, most medical students were no longer taught about this therapy. It is now a rare mainstream doctor who even knows about the previous widespread use of whole thyroid, and there are practically no doctors, aside from those with an interest in integrative medicine, who even realize that whole thyroid preparations are still available for their patients.
Synthetic Thyroid—Pros and Cons
What caused the drastic change in the treatment of hypothyroidism, leading to the rapid decline in the use of whole natural thyroid? It was the commercial introduction, in 1950, of synthetic thyroxine, which is chemically identical to natural thyroxine (which had been discovered in 1916). By the 1970s, almost all the leading medical journals had jumped on the synthetic T4 bandwagon (the best known brand name is Synthroid) and were touting its supposedly consistent potency and stability. Like natural T4, synthetic T4 has a long half-life in the body—it can be given once a day and is then slowly converted to the more biologically active T3.
While the efficacy of synthetic T4 for people who suffer from hypothyroidism can’t be disputed, it is not the safe and stable medication that many in the medical establishment make it out to be. Between 1991 and 1997, there were ten recalls of synthetic T4, involving over 100 million tablets. In nine of these recalls, the tablets had been found to be subpotent, or they were losing their potency before their expiration date; in the tenth recall, the tablets were found to be too potent. For patients, such unreliability means that the synthetic T4 they receive could be either too strong or not strong enough to treat their condition properly.
T4 Alone May Not Be Adequate
Beyond the reliability problem, new research is leading some physicians (even those in mainstream medicine) to question the wisdom of using only synthetic T4 for their patients with subclinical hypothyroidism. A study published in The New England Journal of Medicine in 1999 examined the effects of giving T4 along with small amounts of T3 to hypothyroid patients. The authors concluded, “In patients with hypothyroidism, partial substitution of T3 for T4 may improve mood and neuropsychological function; this finding suggests a specific effect of the T3 normally secreted by the thyroid gland.”
Even with studies such as this, however, most doctors continue to use T4 alone, based in part on the findings of an earlier study showing that people who received both T4 and T3 had a higher frequency of troublesome side effects, including palpitations, irritability, and tremors.
Another study, reported in the journal Endocrinology in 1996, also gave credence to the idea that more than just T4 is needed to optimize thyroid hormone levels in patients with hypothyroidism. In this study, done on hypothyroid rats, the researchers demonstrated that there was no single dose of either T4 or T3 that normalized thyroid hormone concentrations in all tissues simultaneously. It was only through the administration of both T4 and T3 that tissue concentrations of thyroid hormones were normalized.
Whole Natural Thyroid—As Nature Intended
In a perfect world, a large-scale, head-to-head study between synthetic T4 and whole natural thyroid would be done to see which one proved safer and more effective for the millions of people affected by hypothyroidism, whether clinical or subclinical. Until that time comes, it’s good for those of us who believe in the innate wisdom of nature to know that whole natural thyroid, which contains all the hormones found in our own thyroid glands, is available to help ensure our good health.
- McDermott MT, Ridgway EC. Subclinical hypothyroidism is mild thyroid failure and should be treated. J Clin Endocrinol Metab 2001;86(10):4585-90.
- Chu JW, Crapo LM. The treatment of subclinical hypothyroidism is seldom necessary. J Clin Endocrinol Metab 2001;86(10):4591-9.
- Mya MM, Aronow WS. Increased prevalence of peripheral arterial disease in older men and women with subclinical hypothyroidism. J Gerontol Biol Sci Med Sci 2003;58(1):68-9.
- Mya MM, Aronow WS. Subclinical hypothyroidism is associated with coronary artery disease in older persons. J Gerontol Biol Sci Med Sci 2002;57(10):658-9.
- Cakir M et al. Musculoskeletal manifestations in patients with thyroid disease. Clin Endocrinol 2003;59:162-7.
- Sawin CT. Hypothyroidism. Med Clin North Am 1985:69(5):989-1004.
- Foster RC, Thornton MJ. Thyroid in the treatment of menstrual irregularities. Endocrinol 1939;24:383-8.
- Wren JC. Symptomatic atherosclerosis: prevention or modification by treatment with desiccated thyroid. J Am Geriatr Soc 1971;19(1):7-21.
- Federal Register 62, No. 157, 14 August 1997, pp. 43535-8.
- Bunevisius R et al. Effects of thyroxine as compared with thyroxine plus triiodothyronine in patients with hypothyroidism. New Engl J Med 1999;340:424-9.
- Smith RN et al. Controlled clinical trial of combined triiodothyronine and thyroxine in the treatment of hypothyroidism. Lancet 1970;4:145-8.
- Escobar-Morreale HF et al. Only the combined treatment with thyroxine and triiodothyronine ensures euthyroidism in all tissues of the thyroidectomized rat. Endocrinol 1996;137(6):2490-2502.
Dr. Rosick is an attending physician and clinical assistant professor of medicine at Pennsylvania State University, where he specializes in preventive and alternative medicine. He also holds a master’s degree in healthcare administration.