Low thyroid, the unsuspected cause of heart disease (Pt. 3)
An underactive thyroid can affect every cell in the body and be a major contributor to degenerative diseases (1). In previous blogs we looked at hypothyroidism caused by nutritional deficiencies. We saw how the ‘Heart and Body Extract’ and the ‘Gland Extract’ can help the thyroid because they contain iodine, a key nutrient for all the glands. We looked at Dr. Broda Barnes’ research on the link between low thyroid and heart disease.
While hypothyroidism was not very prevalent when Dr. Barnes was doing his research, he already observed this condition was on the rise in the American population. What accounted for the increase in thyroid disease, according to Dr. Barns, was the introduction of antibiotics around 1945, which allowed millions of hypothyroid children to live long enough to reproduce and pass on their low thyroid to their children. Included in this group were those with heart disease and perhaps other major degenerative diseases.
The major problem with why hypothyroidism remained prevalent, according to Dr. Barns, was that it was still widely unrecognized (1). Today, hypothyroidism is one of the fastest rising health conditions in the US. An estimated 27 million Americans have some form of thyroid disease, women being five to eight times more likely than men to develop the disease. Despite this, hypothyroidism still remains unrecognized, misunderstood and undiagnosed, with up to 60% of thyroid disease sufferers not being aware of their condition (2).
New evidence points to the fact that thyroid disorders should be taken more seriously, especially when it comes to how low thyroid affects heart health:
“Hypothyroid patients have increased diastolic blood pressure…, (and) altered lipid profile… Homocysteine, C-reactive protein, increased arterial stiffness, endothelial dysfunction and altered coagulation parameters have been recognized as “new” risk factors for atherosclerosis in patients with thyroid hormone deficiency. The plasma total homocysteine concentration, an independent risk factor for atherosclerosis, is moderately elevated in overtly hypothyroid patients and it decreases with thyroid replacement therapy.” (3)
Something that makes thyroid disorders hard to address is the fact that they rarely affect only the thyroid. In the majority of cases, thyroid disorders involve a myriad of different imbalances, all of which have to be addressed before the thyroid to heal.
In what follows we will look at what other factors, apart from iodine deficiency, affect the health of our thyroid. We will learn about the thyroid’s ‘chain of command’, what the most prevalent type of thyroid disease is and what we can do to start taking care of our thyroid.
What is the thyroid?
The thyroid is a butterfly shaped gland that is located within the neck, just below the trachea. It is not to be confused with the parathyroid, located on the thyroid too, whose function is to release hormones that control calcium and other minerals within the blood.
The thyroid’s main function is to produce the hormones known as T3 (tri-iodothyronine) and its pro-hormone T4 (thyroxine). Both of these hormones are tyrosine-based hormones and are partially composed of iodine; however T4 has four iodine molecules, while T3 has three. Also, T4 is much more abundantly produced in the thyroid than T3 and is consequently much more abundantly released in the bloodstream than T3, at a ratio between 14:1 and 20:1.
T4 is the inactive form of thyroid hormone, and it is also known as ‘storage form’ because it is stored in the body until it is needed. T4 has to be converted to the active form T3 within the cells to be usable. Inside the cells, T3 is three to four times more potent than T4.
A deficiency in iodine can lead to decreased production of T3 and T4, enlarges the thyroid gland and will cause the disease known as goiter (5), which is why supplementing with iodine is key for thyroid health. Please check our “Heart and Body Extract” and “Gland Extract”.
The importance of the thyroid
Scientist Otto Warburg won the Nobel Prize for demonstrating that “cancer develops and thrives when cells become dysfunctional and are unable to efficiently produce energy” (4). This is exactly how cells suffer under conditions of low thyroid, they cannot produce energy.
This will influence:
- The body’s metabolic rate
- Bone growth
- Neural maturation
- Protein, fat and carbohydrate metabolism
- Vitamin metabolism
- Heat generation, etc (5)
The thyroid’s chain of command
Dr. John W. Larson DC, Clinical Nutritionist and Hormone Health Expert for over 18 years, explains that the thyroid follows a very specific and highly coordinated chain of command. Before the active free T3 can reach our cells and be used to make energy, it has to go through different steps in an orderly fashion (10).
For this reason, thyroid function does not start in the thyroid itself, but in brain and the liver, in this order:
1) In the brain: Thyroid hormone is operated by the action of the pituitary and the hypothalamus (2). The pituitary is a very important gland that secretes hormones that help control: growth, blood pressure, certain functions of the sex organs, thyroid, and metabolism as well as some aspects of pregnancy, childbirth, nursing, water/salt concentration at the kidneys, temperature regulation and pain relief (6).
When thyroid hormone is needed, a signal known as ‘Thyrotropin Releasing Hormone’ (TRH) travels to the pituitary and triggers this gland to release another hormone called ‘Thyroid Stimulating Hormone’ (TSH). TSH is sent directly to the thyroid (7) where another hormone called ‘Thyroid Peroxidase’ (TPO) transports iodine into the thyroid gland, adds this iodine to tyrosine and with both of these, makes thyroid hormone (8), about 93% T4 and 7% of T3 (7).
This process is so tightly regulated that the brain is constantly ‘reading’ thyroid hormone levels in the bloodstream. If the brain senses too much hormone circulating in the blood, it will slow down the levels of TSH, and the thyroid will slow down its release of thyroid hormone accordingly. On the contrary, when the levels of thyroid hormone drop in the blood, the pituitary releases more TSH, and more thyroid hormone is produced.
2) In the liver: Once thyroid hormone is made in the thyroid, it is carried into the bloodstream by Thyroxine-binding globulin (TBG). (TBG) is synthesized in the liver as a protein (another word for ‘globulin’) as one of three transport proteins (along with transthyretin and serum albumin) responsible for carrying thyroid hormone T4 and T3 in the bloodstream. Of these three proteins, TBG has the highest affinity for T4 and T3 but is present in the lowest concentration. Despite its low concentration, TBG carries the majority of T4 in the blood plasma (9).
The liver is responsible for converting about 60% of T4 into T3. Any form of liver congestion will interfere with this conversion. Stress hormone will convert another 20% into a permanently inactive form of T3, known as reverse T3. Healthy gastrointestinal flora is responsible for converting the last 20% of T4 into T3 (7).
Apart from being converted in the liver, the main nutrient that helps the conversion of T4 to T3 is selenium. Selenium is another important trace mineral that is also becoming depleted in our soils (10).
Not only does TBG transport T4 and T3 into the bloodstream, it also binds them. In the human body every hormone is found bound to a protein: thyroid hormones, adrenal hormones, sex hormones (estrogen and testosterone), etc. This ‘bounding effect’ is a way the body has to control the powerful effects hormones have in us. It is not until hormones become free or unbound that they can have effects on our cells. In the case of the thyroid, this means that T4 is not in an active form that can be used by cells to produce energy (7).
This whole chain of command has the important purpose of making active free T3 available to all cells. This happens inside the part of the cell called the mitochondria, where energy is produced.
Reverse T3 (RT3) dominance
RT3 is like an anti-T3 hormone in that it blocks T3 from getting to the cells by binding to the receptor site that is normally occupied by T3.
The role of diagnosis
According to Dr. Larson, there are many tests used to check thyroid function. However, on many occasions, practitioners will only use one of these. He recommends having a complete thyroid panel that includes six different tests:
- TSH: It is a good indicator of thyroid function so this test is the most widely used test by most practitioners. There are two problems with it though, one, sometimes it is the only test used and two, it can show healthy levels of TSH even when the person still has low thyroid symptoms. This adds to the confusion and frustration that is normally seen in thyroid disease. According to Dr. Larson, more detailed testing is needed to show other factors that may be contributing to low thyroid function.
Something that needs to be taken into account is that if the patient is on thyroid medication, TSH levels can show up as too low.
When it comes to the ranges, the optimal level of TSH would be between 1.00 and 2.50, with 0.00-0.44 being clinical low and 4.51 or higher being clinical high.
- Free T3: Optimal ranges are between 2.8 and 3.8.
High levels of T3 are a sign of an overactive thyroid. If free T3 is low it is a sign that the conversion process may be suffering.
- Reverse T3: Optimal levels are between 0.0 and 19.9.
RT3 mimics free T3 in the body but does not carry out the active duties for metabolic processes in the same way. There are several reasons why RT3 can be high. One is high levels of T4. Another reason is too much of the stress hormone cortisol, which causes what is known as ‘stress induced hypothyroidism’ (7).
- Free T4: Optimal levels are between 1.03 and 1.56.
If T4 is high, this tells us that the thyroid is overactive and producing too much thyroid hormone. It could also mean that the conversion of T4 to T3 is not occurring in the liver and/or gut. If Free T4 is low, this points to an underactive thyroid. However, it does not tell us if the problem is functional or autoimmune related (7).
- Thyroid Peroxidase Antibody: This is one of the tests done to check for an auto-immune thyroid condition. The optimal level is from 0 to 19. As we saw before, Thyroid Peroxidase (TPO) transports iodine into the thyroid. In the case of an auto-immune thyroid disease, antibodies attack this enzyme, which can cause keep enough thyroid hormone from being available, even if the person is supplementing with iodine.
There has been some concern expressed by practitioners which explain that taking too much iodine, 50 mg or more, can actually be hurtful in the case of TPO antibodies. Dr. Edwin Lee, MD, Board Certified Endocrinologist explains the extra iodine can actually fuel the antibodies even more, therefore, he recommends to stay at a low dose of 1-2 grams until the auto-immune condition is addressed.
- Thyroglobulin Antibody, also known as Anti-Thyroglobulin Antibody, is also a test that measures auto-immunity. When the body is creating anti-bodies toward this protein, the one that carries thyroid hormone into the bloodstream, it can keep T3 from reaching the cells.
Auto-immune thyroid disease
Approximately 80 % of hypothyroidism cases are autoimmune based (7). It is called ‘Hashimoto’s Thyroiditis’ when it causes low thyroid and ‘Graves disease’ in the case of hyperactive thyroid.
Auto-immunity can be caused by different things, among them, leaky gut, food allergies or intolerances, invading organisms, heavy metals that have entered the thyroid, inflammation, etc.
The most prevalent is related to the gut. According to Dr. Ritamarie Loscalzo MS, DC, CCN, DACBN, the health of the thyroid is dependent on the health of the gut. She explains that around 70 % of our lymphatic system is located in the gut, known as GALT (Gut Associated Lymphatic Tissue). Eating the wrong kind of foods can irritate the cells lining the gut (enterocytes) and produce inflammatory chemicals which will over-sensitize the immune system, create more inflammation and ultimately lead to leaky gut (11).
Dr. Tom O’Bryan, DC, CCN, DACBN explains that the dendritic cells in our immune system are like guards that check every food we eat. When we constantly eat inflammatory foods we over stimulate these cells to produce inflammatory chemicals called ‘cytokines’. They are like ‘chemical bullets’ that destroy any invader by making antibodies against invaders. In the case of protein foods like wheat and grains, the problem is that they contain a long chain of 33 amino acids, called ‘alpha gliadin’ that is not broken down correctly. This is a problem because any food that is not broken down completely will alert the immune system that an invader is present. When it comes to the thyroid the problem is that our thyroid is made out of exactly the same chain of amino acids that is found in these foods. Once our immune system is activated against wheat and grains, it will start attacking our thyroid too and making antibodies against our own thyroid. This is what is known as ‘collateral damage’.
The immune system can attack the thyroid itself, or any of the hormones, or proteins that are part of the thyroid’s chain of command. This is why it is important to have a complete thyroid lab panel to check for all the possibilities.
There is only one thyroid dysfunction that is not shown in any test: when antibodies attack the thyroid receptors in the cells. If these receptors are damaged or destroyed, the cells are unable to receive T3, however, all the tests will show normal levels of TSH, T4 and T3 but the patient will still have symptoms of low thyroid.
Once auto-immunity becomes chronic, and we surpass our oral tolerance for problem foods, thyroid antibodies will become self-perpetuated (12). This will make the sufferer over-sensitive to any other minor irritants like pollen, dust, even less evident things like perfumes. It will also make the sufferer more prone to other auto immune conditions like rheumatoid arthritis, etc if the problem is not addressed at the root level.
The treatment usually given for thyroid disorders is T4 thyroid hormone, but this doesn’t solve the problem, because as long as the offending agents are present in the diet the damage will continue. What is more, giving the patient T4 hormone can lower thyroid function even more.
So what can we do to start reversing thyroid dysfunction? Please find out in our next blog.
- Barnes, Broda O., and Lawrence Galton. Hypothyroidism: The Unsuspected Illness. New York: Crowell, 1976. Print.