Because the thyroid has its fingers in so many pots, when its function drags, so does that of many other systems (digestive, hormonal, etc.). It can seem like a vicious cycle. The conventional approach has long been to treat the thyroid so that the other systems it affects will normalize, too. That may work if thyroid hormones are truly needed, bu frequently they are inappropriately prescribed, possibly causing more harm than good in the long run. Here are some of the functions that come under the gland’s influence:
Bone Metabolism: Although the parathyroid gland (similar name, totally different gland) controls calcium levels in the blood, the thyroid can also affect one’s calcium status. That’s partly because the thyroid gland manufactures and stores calcitonin, a calcium-regulating hormone. Also, hypothyroidism prevents the ends of the long bones from forming fully or correctly. This won’t show up as a calcium deficiency on a blood test unless you are looking at the ranges from a “functional” perspective. By that I mean the level that indicates good health.
Gastrointestinal Function: Chronic constipation is a common complaint of people with an underactive thyroid gland. Poor thyroid function slows down the amount of time it takes for food to move through the intestines. This in turn increases the potential of gut infections from harmful yeast and bacteria, leading to inflammation, poor nutrient absorption, and an increased risk of developing food intolerances.
Male Reproduction: Hypothyroidism in men has been shown to diminish sex drive and cause impotence and a poor sperm count. Although hypothyroidism is rare in men, it must be ruled out when they have testosterone and estrogen imbalances.
Gallbladder and Liver: The liver has several channels through which it metabolizes hormones, filters toxins, and cleans the blood. By products from these processes are dumped into the gallbladder for final removal. Low thyroid function bogs down this whole process, making the liver and gallbladder sluggish and congested and contributing to gallstones. Gallbladder X-rays in hypothyroid individuals often show a distended gallbladder that contracts sluggishly. And since thyroid hormones are converted into a usable form in the liver, you can see how hypothyroidism creates a vicious cycle — hypothyroidism stymies liver function so that fewer thyroid hormones become active.
Growth Hormones: Just because you’re an adult doesn’t mean you don’t need growth hormone (GH) for regenerating cells and tissues. The pituitary gland releases these “anti-aging” hormones to be dispatched where cell creation and growth are needed. GH then stimulates the synthesis of insulin-like growth factor (IGF-1) in the liver in order to complete the job. During this conversion process, an inadequate amount of thyroid hormones (hypothyroidism) can muck things up, since a healthy amount of thyroid hormones are needed to make IGF-1.
Fat burning: One of the most frustrating symptoms of hypothyroidism is the inability to lose weight, even when calories are low and hours are logged on the treadmill are high. Hypothyroidism simply slows down the body’s overall metabolism and fat burning. For instance, the adrenal hormones epinephrine and norepinephrine that enhance far burning lose power when the thyroid is underactive. What’s more, low thyroid function makes it harder for the body to burn far by shutting down the sites on the cells that respond to lipase, an enzyme that metabolizes far. So not only does stored fat refuse to budge, but also the inability to burn fat for energy contributes to fatigue and chronic cravings for sweet and starchy foods. Lastly, since hypothyroidism hinders human growth hormone, building muscle through exercise is difficult if not impossible and muscle loss can occur.
Insulin and Glucose Metabolism: Glucose (sugar) metabolism is the rate at which the body uses glucose to make energy. That fuzzy, foggy brain and poor memory so common with hypothyroidism? The brain is the most voracious consumer of glucose, so when glucose metabolism is poor, so is brain function. People with low thyroid function absorb glucose more slowly than normal and their cells don’t use its energy as readily. Furthermore, once glucose is absorbed, the body falls behind in eliminating it. Put it together, this creates hypoglycemia, or too little sugar available for energy, with symptoms of fatigue, irritability, and light-headedness. The problem is not too little glucose in the blood, but rather that the glucose can’t get into the cells. In fact, glucose blood tests may be normal while symptoms of hypoglycemia rage on. To compensate for low energy, the adrenal glands pump out stress hormones, which activate the liver to release stored glucose into the bloodstream for energy. Eventually this repeating scenario exhausts the adrenal glands, as well as the brain’s hypothalamus and pituitary gland, which are responsible for orchestrating so many body functions. Interestingly, hypothyroidism also makes it harder to break down insulin medication, so that diabetics need to take less than they normally might.
Thyroid hormones and cholesterol: When I see high triglycerides, high cholesterol, and high LDL (“bad”) cholesterol on a blood panel, I always want to rule out thyroid dysfunction before doing anything else. When a a person’s thyroid is functioning below normal, he or she makes fat much more quickly than it’s burned, which drives up triglycerides, cholesterol, and LDL cholesterol. As mentioned earlier, hypothyroidism makes the liver and gallbladder sluggish, so that fat is not easily metabolized and cleared from the body. Cells may be less receptive to taking up LDL, so that too much accumulates. When a person with healthy thyroid function becomes hungry and needs energy, the body is able to readily burn fat for fuel. Not so with low thyroid function. When one of my patients with abnormal lipid panels (cholesterol and triglycerides) has hypothyroidism, I address the thyroid disorder first, after which the lipids in circulation often reach normal levels.
Brain chemistry: The adrenal glands, located on top of the kidneys, are our stress-management glands. With hypothyroidism, they do not exert the same energizing effect on the brain as they normally would. This can lead to depression, mood disorders, lethargy, and weight gain.
Estrogen Metabolism and Breast Cancer: Estrogen must first be made water-soluble in the liver in order to be eliminated from the body. During this process some of the hormone forms a secondary type of estrogen, such as estradiol. Hypothyroidism appears to hinder pathways in the liver that make this possible. The result is the production of too much so-called proliferative estrogen, which may lead to breast cancer, uterine fibroids, and ovarian cysts.
Adrenal hormone metabolism: I don’t like to use urinary adrenal tests for this reason: In people with hypothyroidism, urinary excretion of several adrenal hormones decreases. Instead I prefer salivary adrenal tests. In other words, with the urine test, someone could appear to have an advanced case of adrenal fatigue when in fact they are simply doing a poor job of clearing the hormones through the kidneys.
Liver detoxification: Thyroid hormones affect the liver cells responsible for detoxification most of all. The liver has two phases of detoxification. In Phase I, fat-soluble hormones are made water-soluble so the body can eliminate them. This process is finalized in Phase II, and the end products are excreted via the feces, sweat, or urine. It is in Phase II where good thyroid health is most important. When thyroid function is low, the enzymes, or “spark plugs,” that carry out the detoxifying tasks, simply don’t mature, hindering detoxification. I often see people who do poorly at any attempts at detoxification until thyroid function is restored. Again, this is one of those vicious cycles, as healthy liver function is integral to converting thyroid hormones into a form the body can use.
Stomach acid production: Most people think of stomach acid as bad, the sort of thing that causes heartburn. In fact, sufficient stomach acid prevents heartburn by thoroughly digesting your food. (The burning sensation from heartburn is actually from the poorly digested food rotting in your gut and shooting up into your esophagus, not from excess stomach acid.) Sufficient stomach acid, or hydrochloric acid (HCl), prevents food poisoning, parasites, and other bad bugs from gaining a foothold in digestive tract. Lastly, plenty of HCL stimulates the gallbladder and pancreas to complete digestion and preserve the integrity of the whole gastrointestinal tract. The production of HCL depends on the hormone gastrin, which diminishes with hypothyroidism. This can cause such digestive complaints as heartburn, bloating, and gas; hinder the absorption of such vital nutrients as B12, iron, and calcium; and lead to inflammation, lesions, and infections of the intestines. Hypothyroidism and low HCL often go hand in hand.
Protein Metabolism: Another crucial job stomach acid performs is digesting proteins. In people with hypothyroidism and low stomach acid (hypochlorhydria), protein deficiency may occur. In most cases, simply restoring thyroid function resolves the problem.
Body Heat and Hot Flashes: Since the thyroid maintains body temperature, a person with hypothyroidism may develop abnormalities related to body temperature, such as hot flashes and night sweats. These symptoms may be confusing because they are usually associated with perimenopause. Therefore testing the female hormone levels ensures addressing the right disorder. Although the thyroid is most commonly associated with regulating body temperature, the ovaries and adrenals affect it, too. A female hormone panel helps determine whether hot flashes and night sweats are caused by estrogen fluctuations or not. If a thyroid disorder causes these symptoms, it’s likely other signs of thyroid malfunction are present as well, When the adrenal glands are to blame, the person does not suddenly feel hot, but the adrenal hormone shifts do prompt a sweating attack.
Progesterone Production: Progesterone and thyroid hormones are intimately connected. Remember that when the pituitary sends TSH to the thyroid, the gland makes T4 and T3 out of thyroglobulin and iodine? The catalyst for this is the enzyme, thyroid peroxidase (TPO), which resides in the follicles of the thyroid gland. (Thyroid follicles are small spheres of hormone-producing cells within the gland.) Progesterone appears to both improve the signaling mechanisms of thyroid receptors as well as stimulate TPO production. One reason why a woman’s body temperature rises when she ovulates is that the normal progesterone surge that occurs at this point in cycle ramps up TPO activity , which stimulates overall thyroid activity and metabolism. Progesterone’s effect on TPO — too little progesterone depresses TPO activity, lowering T4 production — also explains why a woman with a progesterone deficiency may have mostly normal thyroid levels but a low T4 level. Symptoms of progesterone deficiency include heavy menstrual bleeding, an inability to lose weight, depression, headaches, and other symptoms in the middle of her cycle.
The answer for these women, particularly menstruating women, is not to prescribe progesterone creams. This approach does not take into account the reason for the deficiency, which most often stems from a sluggish pituitary gland (remember, the pituitary is the air traffic control tower that orchestrates the hormones). And factors that lead to poor pituitary function include adrenal fatigue, taking oral contraceptives, or even postpartum hormonal changes. For menopausal women for whom pituitary function may never rebound, sublingual progesterone may be in order. (Progesterone creams almost always guarantee a buildup of excessive levels of progesterone in the fat tissue.) For both menstruating and menopausal women, however, supporting the adrenals is integral.
Severe hypothyroidism can lead to loss of ovulation and insufficient progesterone, the buildup of too much tissue lining of the uterus, and excessive and irregular bleeding. Ultimately hypothyroidism raises the risk of infertility and miscarriage.
Lastly, thyroid hormones sensitize the body’s cells to progesterone, so that they are able to readily take it up when needed. When the cell’s progesterone receptor sites are not exposed to enough thyroid hormones, they lose the ability to allow progesterone is circulating through the bloodstream, a woman will have symptoms of progesterone deficiency and on progesterone levels will show abnormal surges and dips.
Thyroid Hormones and Anemia: Hypothyroidism can lead to anemia in three different ways. For instance, anemia resulting from a B12 and folic acid deficiency usually stems from low stomach acid, one possible consequence of hypothyroidism. Secondly, about 12 percent of people with hypothyroidism have pernicious anemia, an autoimmune disorder in which the body’s immune system destroys a compound in the stomach lining necessary for the absorption of B12. Given that the vast majority of hypothyroid cases are also an autoimmune disorder in which the body destroys its own thyroid gland, it’s not surprising that a hyperactive and malfunctioning immune system can lead to both pernicious anemia and hypothyroidism. Lastly, since hypothyroidism leads to a deficiency in stomach acid, iron absorption (among other things) is poor. And remember how hypothyroidism makes it hard for progesterone to get into the cells? That effect causes excessive bleeding during menstruation, and poor iron absorption from low stomach acid coupled with excessive bleeding brings on anemia of iron deficiency.
Protein Binding: Earlier I mentioned that when the thyroid hormone is traveling to the liver or to various cells, it catches a ride with binding proteins that serve as taxicabs. The same is true for the reproductive hormones, whose taxis are called sex hormone-binding globulins (SHBG). When these “bound” hormones arrive at their destination, they are “free.” Research shows that an underactive thyroid reduces SHBG levels. In addition to contributing to hormonal imbalances, low SHBG levels can also skew hormone test results.
Heart: Too much homocysteine, an amino acid made in the body, seriously increases the risk of heart disease, as well as dementia and neurodegenerative diseases. Hypothyroidism appears to contribute to high homocysteine levels by compromising the liver’s ability to manage the amino acid.
***This information is credited to: Datis Kharrazian, DHSc, DC, MS