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Understanding the thyroid connection to weight loss and the wide range of other health consequences it can impact.

Our last discussion, devoted to weight loss, considered thyroid health and balance; a potentially key contributor to successfully managing weight. In this segment we’ll delve more deeply into the effects, challenges of health monitoring and clinical support of this important gland, since a dysfunctional thyroid can thwart well-intentioned attempts at a weight loss program, as well as disrupt any number of functions bearing broadly on human health and wellness.

For context;

1) Thyroid dysfunction affects approximately 20 million Americans.
2) It is estimated that approximately 60% of those with thyroid disease are unaware of it.
3) Women are 5 times more likely than men to develop a thyroid condition.
4) Nutritional deficiencies can contribute to thyroid dysfunction.

Yet, despite its prevalence, proper assessment of thyroid dysfunction can be illusive and conditions can go unnoticed/undiagnosed by health care practitioners.

So, what’s a thyroid, anyway?

The thyroid is a butterfly-shaped gland located in your neck. It is responsible for producingthyroid hormones (triiodothyronine or T3), thyroxine (T4) and calcitonin. T3 is the active form of thyroid hormone, and its purpose is to maintain metabolic rate (your metabolism), growth and development. When the thyroid malfunctions, (like any other gland in the body may do), health issues, (obesity, for example) will most certainly follow.

What Tests are used to evaluate thyroid function?

The standard tests used, conventionally, to determine your thyroid health are TSH, Total T4, and some doctors may measure Total T3 as well. However, in the broadest scope of monitoring thyroid health, these are very limiting tests and consequently, the information gleaned can be inconclusive or misleading, We will discuss more appropriate testing markers later on, but know that each of these markers have their own purpose.

TSH, or Thyroid Stimulating Hormone, is a signaling hormone that is stored in the pituitary gland within your brain. It is released under the control of the hypothalamus (the regulatory or control center), which is also part of your brain. When your body needs more thyroid hormone, the hypothalamus signals the pituitary to release TSH. TSH circulates in the blood until it reaches the thyroid gland. Once there it, in turn, signals the thyroid to produce several hormones, designated T4, T3, T2 and T1. (Note: the roles of T1 and T2 are still yet to be fully determined.) The majority of hormone produced in the thyroid is Thyroxine, or T4 hormone (approximately 80% - 90% of all thyroid hormone). Although Triiodothyronine, or T3, (approximately 10% - 20% of all thyroid created hormone) is produced in the thyroid gland as well, most of this hormone is formed outside the gland through the conversion of T4 hormone, which ultimately is used in each cell in your body. Most of the T3 that your body needs is formed through the conversion of T4. This conversion mainly takes place in the liver and kidneys, although it also occurs in cells throughout the body. T4’s conversion to the active form of thyroid, T3, is accomplished through an enzyme called deiodinase, as well as various nutrients. (See “Nutritional Deficiencies” below).

Why Standard Tests for Thyroid Health Tend to Fail

Even with medical advancements, knowledge and testing, thyroid conditions are very much underdiagnosed for various reasons. As noted earlier, the limited number of markers typically targeted may not illustrate a true picture of thyroid function

To explain this as simply as possible, Total T4 is a measurement of all the T4 hormone in your body, which includes T4 that is both bound and unbound to proteins (free-T4). Total T4 hormone is mostly made up of protein bound thyroid. Bound hormone is not readily available to use in your body. Your body needs thyroid hormone that is readily available, or in its free (unbound) form. This is why it is most important to test free-T4 (FT4) and free-T3 (FT3). A doctor should measure both of these hormones to properly assess thyroid hormone conversion and function. Let’s say that your doctor only tests TSH and free-T4 and finds that they are both normal, but you still have symptoms that match a thyroid condition, such as hypothyroid (underactive thyroid). Without testing the free-T3, you would be missing the bigger picture.

There are many instances where patients have an issue with the deiodinase converting enzyme and have a low FT3 level. In these instances, if FT3 isn’t tested, the condition may go undiagnosed for a long time, leading to worsening symptoms or even treatment tied to an inaccurate diagnosis. In addition to a conversion issue, the levels of T3 in your brain can be different from that in the rest of the body’s tissues (peripheral tissue), as well as the levels in your blood. This means, for example, that you can have normal T3 levels in your brain, and even your blood, while other parts of your body are experiencing deficiencies, or vice versa. And, if T3 is responsible for metabolic function, these deficient areas will cause you to experience signs and symptoms of hypothyroidism (see “Some Signs and Symptoms of Hypothyroidism”, below). Another issue to consider is that your body could be deficient in particular minerals, such as selenium, zinc, B-vitamins, iodine, and amino acids, all which additionally, contribute in some way to the formation of thyroid hormone and/or the conversion of T4 to T3. A deficit in any of these substances could lead to a free-T3 shortage, while T4 and TSH appear to be normal, or even increased.

What’s "in range"?

Even if all the appropriate testing markers are measured, conventional medical training leads most doctors to rely on the so-called ‘normal ranges” to be sufficient in their evaluation of blood test results. Unfortunately, the normal ranges are based on an average of, what’s thought to be, a large group of healthy people. This group includes everyone from young adults to the elderly. Unless your results fall outside of the “normal range,” your doctor may believe that everything is normal. Recent scientific studies have demonstrated the “normal” range for TSH (0.45−4.5) is, in fact, outdated and too wide to effectively assess thyroid function. This holds true for FT4 and FT3 as well. Among the complement of tests that would be regarded as relevant in assessing a patient’s thyroid health are TSH, Free-T3, Free-T4, Reverse-T3 (rT3), thyroid antibodies (Thyroid Peroxidase Antibodies or TPO Ab, Anti-thyroglobulin Antibodies or Tg Ab, Thyroid-Stimulating Immunoglobulin or TSI, which is associated with Graves’ Disease), and Iodine levels.

The many opportunities for deceptive or incomplete findings, make it all the more important for a practitioner to record and understand all signs and symptoms as a basis for a reliable clinical diagnosis. Sometimes, this cognitive step many be the only way to determine thyroid dysfunction

Some Signs and Symptoms of Hypothyroidism (low thyroid function)

  • Low body temperature (must be done properly)
  • High Cholesterol
  • Weight gain/resistance to
  • Heart Palpitations
  • Depression
  • Muscle cramping, joint pain
  • Fatigue
  • Panic attacks
  • You feel cold when others don’t
  • Slow or decreased heart rate
  • Feeling jittery or anxious
  • Hoarse voice
  • Appetite or taste buds altered
  • Slow reflexes
  • Brain fog (can’t think clearly)
  • Infertility
  • Poor memory and/or concentration
  • Carpal Tunnel Syndrome
  • Low interest in sex (decreased libido)
  • Brittle nails
  • Thin and/or coarse or dry hair
  • Insomnia
  • Loss of hair, especially the outer1/3 of your eyebrows
  • Poor circulation
  • Fluid retention
  • Dry skin
  • Eczema
  • Constipation (bowel movement every 2 or more days)
  • Yellowing of skin and palms
  • Neck feels swollen
  • Change in menses (periods)
  • Puffy face
  • Pain in extremities (arms, legs, hands, feet)
  • Muscle stiffness
  • Cancer (in extreme hypo-thyroidism)
  • High blood pressure (hypertension)
  • Change in sleep patterns
  • Agitation

Causes of Thyroid Dysfunction

There are various reasons for thyroid dysfunction, including hypothyroidism (underactive thyroid) and hyperthyroidism (overactive thyroid)]. These range from nutritional deficiencies (including diet, vitamins, minerals), to environmental toxins see “. Even medications that you may be taking can possibly affect your thyroid. In addition, age and other medical conditions can play a part in thyroid dysfunction. See below for more information on possible causes of hypothyroidism (underactive thyroid function).

Nutritional Deficiencies:

  • Fasting, Starvation, Anorexia, Protein or Calorie Malnutrition
  • Vitamin Deficiency:
    • A, E, B12, B2, B3
  • Mineral Deficiency:
    • Selenium, Iodine, Iron, Zinc
  • Amino Acids Deficiency:
    • Cysteine, Tyrosine (with Iodine forms Thyroid Hormone)
  • hormones by interfering with iodine uptake in the thyroid gland. (e.g., cabbage, kale, Brussels sprouts, and others), although there is a way to eat these vegetables while reducing their effects.

Hormone Deficiencies:

    Cortisol, Testosterone, and Estrogen imbalance (in excess)

Environmental Toxins and Nutritional Deficiencies:

  • Heavy Metals: (Mercury, Cadmium, Lead)
    • Mercury can reduce or prevent the formation and conversion of thyroid hormone (exposure usually from eating fish or from handling old broken thermometers incorrectly)
  • Halogens: (Perchlorate, Chlorine, Fluorine, and Bromine)
    • All are found in our environment, and are in common substances such as household products (drinking water, beverages, toothpastes, and cleaning supplies)
      • Perchlorates inhibit iodine uptake Chlorine inhibits iodine uptake
      • Bromine displaces iodine and inhibits thyroid activity
  • Pesticides:
    • Decrease TSH, FT3 and FT4
  • Radiation:
    • X-rays, CT-Scans
  • Excesses of:
    • Calcium, Lithium, Copper (impair conversion of T4 to T3)
    • Soy (impairs conversion of T4 to T3)
    • Estrogen
  • Medications:
    • For example: amiodarone, carbamazepine, lithium, phenobarbitone, phenytoin, rifampin, and others
      • These medications can induce goiters (abnormal enlargement of your thyroid gland) and suppress thyroid function.

Summarily, whether it is in the context of a weight loss issue, or to uncover/identify the root of any potential thyroid-related problem, it is important to test for many of these thyroid-depleting substances, as well as nutritional absorption. In addition, a thorough history of a patient’s present condition and investigation of family medical history, should be conducted along with a physical exam. Specialized tests to help determine a patient’s overall health should be brought to bear. It’s key to remember that, even though thyroid conditions may not always be obvious through conventional tests, with proper training and a wider range of diagnostic tools, a doctor can better determine thyroid health and function and enable targeted remediation.