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Bodrero 1
Research Paper on Hypothyroidism
Lisa Bodrero
Jean Widdison
Nutrition 1020-054
November 7, 2011
Bodrero 2
Lisa Bodrero
Jean Widdison
Nutrition 1020-054
7 November 2011
Hypothyroidism
The thyroid may be a small gland in the neck, but when it’s not working properly it
causes big problems that affect many people. “At any given time in the United States, more
than 30 million people suffer from a thyroid disorder, more than 10 million women have lowgrade thyroid imbalance, and nearly 10 million people with thyroid imbalance remain
undiagnosed” (Arem 4). Hypothyroidism once diagnosed, requires lifelong treatment.
The thyroid is part of the endocrine system and is a butterfly-shaped gland in the front
of the neck whose hormones control the way the body uses energy (webmd.com). The thyroid
hormones target most organs which affects “increased oxygen consumption, overall growth,
brain development of the nervous system” (Wardlaw 94). The thyroid “uses iodine from food
to make two thyroid hormones: thyroxine (T4) and triiodothyronine (T3)” (webmd.com). These
hormones are then stored and used when needed. Hypothyroidism is the condition where the
thyroid is not making enough of these thyroid hormones (webmd.com). The thyroid receives
instructions from the pituitary to “secrete hormones which determine the pace of chemical
activity in the body, the more hormone in the bloodstream, the faster the chemical activity; the
less hormone, the slower the activity” (ncbi.nlm.nih.gov). Since the thyroid’s main purpose is to
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run the body’s metabolism, people with hypothyroidism will have symptoms associated with a
slow metabolism (Norman). There are many symptoms of hypothyroidism including: fatigue,
sluggishness, increased sensitivity to cold, pale and dry skin, brittle fingernails and hair,
unexplained weight gain, muscle weakness, muscle aches and stiffness, heavier than normal
menstrual periods, depression, memory problems, constipation and irritability (mayoclinic.com,
ncbi.nlm.nih.gov, Norman).
As mentioned previously, the thyroid gland produces two main hormones, thyroxine (T4) and triiodothyronine (T-3). “They maintain the rate at which your body uses fats and
carbohydrates, help control your body temperature, influence your heart rate, and help
regulate the production of protein” (mayoclinic.com). When the thyroid doesn’t produce
enough hormones, the balance of chemical reactions in the body can be upset (mayoclinc.com),
and in the case of hypothyroidism, the thyroid doesn’t produce enough of T-4 and T-3.
There are a few main causes of hypothyroidism. The “most common cause of
hypothyroidism is inflammation of the thyroid gland, which damages the glands cells”
(ncbi.nlm.nih.gov) which is called an autoimmune disease. The most prevalent form of an
autoimmune disease is Hashimoto’s thyroiditis. "It occurs in about 0.3 - 5 people per 1000 per
year, and women are 15 - 20 times more likely than men to develop this disease" (umm.edu).
Hashimoto's is a condition where the immune system attacks the thyroid gland
(ncbi.nlm.nih.gov). The body's natural defenses "produce antibodies that over time destroy the
thyroid tissue. And as a result the thyroid cannot make enough thyroid hormone"
(webmd.com).
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Some other causes of hypothyroidism arise from having thyroid surgery. "Part of all of
the thyroid hormone gland may be removed to treat disorders such as having too much thyroid
hormone (hyperthyroidism), an enlarged thyroid gland (goiter) that makes swallowing difficult,
thyroid cancer, or thyroid nodules that may be overactive or cancerous" (webmd.com). If the
whole thyroid is removed, then the patient will definitely become hypothyroid. If some of the
gland is left, the body may be able to make enough thyroid hormone to keep blood levels
normal (American Thyroid Association).
Radioactive iodine therapy, which is often used to treat hyperthyroidism, is also a cause
of hypothyroidism, “The radioactive iodine destroys the overactive thyroid cells”
(cpmcnet.columbia.edu). Thyroiditis is another cause of hypothyroidism. Thyroiditis is an
inflammation of the thyroid, causing the thyroid to “dump its whole supply of stored thyroid
hormone into the blood at once, causing brief hyperthyroidism; then the thyroid becomes
underactive” (American Thyroid Association). Radiation therapy is also a cause. Radiation,
used to treat cancer in the head and neck could affect the thyroid gland and lead to
hypothyroidism (mayoclinic.com). Excessive iodine can also reduce the function of the thyroid
(webmd.com). “Iodine is critical to thyroid health—too much or too little can cause it to stop
working correctly” (Norman).
A less common cause of hypothyroidism may occur when taking certain medications.
Lithium, used to treat depression and bipolar disorder, is one of the most common “because
lithium slows the production and release of thyroid hormones, a significant amount of
patients– 20-30%, in fact– develop hypothyroidism” (Norman). Other medications include
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Amiodarone, used to treat heart rhythm conditions, has high iodine content “which can inhibit
the synthesis and release of thyroid hormone” (Norman). Interferon-alfa can also cause a small
number of patients to develop a thyroid disorder (Norman).
Although anyone can develop hypothyroidism, there is an increased risk if you are a
woman older than age 50, have an autoimmune disease – such as type 1 diabetes or
rheumatoid arthritis, have a close relative with an autoimmune disease, have been treated with
radioactive iodine or anti-thyroid medications, have had radiation to the neck or upper chest,
or have had thyroid surgery (mayoclinc.com, Norman).
The most effective treatment for hypothyroidism is by using thyroid hormone medicine.
The most reliable thyroid replacement hormone, Levothyroxine is manmade (webmd.com).
“The purpose of treatment is to replace the thyroid hormone [T3 and T4] that is lacking.
Levothyroxine is the most commonly used medication” (ncbi.nlm.nih.gov) because “while T3 is
[a] stronger [hormone], taking synthetic T4 hormone (Levothyroxine) is considered the
standard treatment” (Norman). This is because most T3 used to be T4 hormone (Norman).
Doctors will prescribe the lowest dose of hormone replacement that is possible, to
effectively bring your thyroid stimulating hormone (TSH) level to a normal range (ncbi.nlm.gov).
“To determine the right dosage of Levothyroxine… your doctor generally checks your level of
TSH after two to three months. Excessive amounts of the hormone can cause side effects, such
as: increased appetite, insomnia, heart palpitations, and shakiness” (mayoclinic.com). Once
treatment is started and at the level needed, you should only get your level checked every year
(mayoclinic.com). Lifelong therapy is required and medication must still be taken even when
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symptoms go away (ncbi.nlm.gov, webmd.com). Sometimes the symptoms of hypothyroidism
continue. This happens if not enough thyroid hormone or the medicine isn’t being absorbed
(webmd.com). As a result, your doctor may increase the dose of hormone or try a combination
of T3/T4 medicine instead of just T4 (webmd.com). Also “treatment during pregnancy is very
important because hypothyroidism can harm the developing fetus” (webmd.com). If
hypothyroidism is developed during pregnancy, treatment should be started immediately. The
dose of medication while pregnant may need to be increased by 25% to 50% (webmd.com).
Hypothyroidism could require lifelong treatment if developed after pregnancy (webmd.com).
There is no prevention for hypothyroidism (ncbi.nlm.gov, webmd.com). “Although you
can’t prevent hypothyroidism, you can watch for signs of the disease so it can be treated
promptly” (webmd.com). The American Thyroid Association recommends that all adults be
tested at least at age 35 and continually every 5 years (webmd.com). “Older adults, especially
women older than 60, and those who have Addison’s disease, rheumatoid arthritis, pernicious
anemia, or type 1 diabetes should also be tested, according to these recommendations”
(webmd.com).
Having low thyroid hormones contributes to excessive hunger and can cause weight
gain (Arem 123). “This weight gain is best explained by the slowing of the body’s metabolism,
so the breakdown of fat and energy is much lower than normal” (Arem 123). “The inefficiency
also increases your cravings” (Arem 123). This in turn will affect eating behavior.
There is really no special diet that affects hypothyroidism. According to Todd B.
Nippoldt, M.D. of the Mayo Clinic, “Although claims about hypothyroidism diets abound,
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there’s no evidence that eating or avoiding certain foods will improve thyroid function in
people with hypothyroidism” (mayoclinic.com). Too much dietary fiber can impair the
absorption of the thyroid hormone (mayoclinic.com). Also certain foods, supplements and
medications can also impair absorption like walnuts, soybean flour, cottonseed meal, iron
supplements, calcium supplements, antacids that contain aluminum or magnesium, some ulcer
medications, and some cholesterol-lowering drugs (mayoclinic.com). It is best to avoid taking
the thyroid hormone at the same time as these foods and medications (mayoclinic.com).
Activity and exercise is very important to help overcome the symptom of weight gain in
hypothyroidism. Regular exercise will improve the rate of metabolism, which will help lose
weight (thyroid-guide.org). “Exercise raises tissue sensitivity toward the thyroid hormone and
encourages its secretion from the thyroid gland” (thyroid-guide.org). It is a good idea to design
a cardiovascular exercise program that can easily be maintained without over exercising (Kunz).
It is suggested that you should exercise 4 to 5 days a week for about 30 minutes a day (thyroidguide.org). “Strength training helps boost metabolism and strengthens muscles, which can
counteract hypothyroidism’s slowing of your metabolism and weakening of your muscles”
(Kunz). Exercising is very important to maintain your health, and it’s even more important
when you have hypothyroidism to help maintain your goal weight.
There is no real way to prevent hypothyroidism, but you can learn how to live with it.
By knowing the causes and symptoms, you can catch hypothyroidism and treat it before the
hormone levels become too low. Knowing how to cope and treat hypothyroidism will be
beneficial because it is a lifelong treatment.
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American Thyroid Association. “Hypothyroidism.” Thyroid.org. 2005. Web. 02 November 2011.
Arem, Ridha, M.D. The Thyroid Solution. New York: Ballantine Books, 2007. Print.
"How Exercises Benefit in Hypothyroidism." Thyroid-guide.org. 2011. Web. 05 November 2011.
"Hypothyroidism - Causes." www.umm.edu. 21 May 2009. Web. 05 November 2011.
"Hypothyroidism - MayoClinic.com." MayoClinic.com. 12 June 2010. Web. 28 October 2011.
"Hypothyroidism - PubMed Health." www.ncbi.nlm.nih.gov. 19 April 2010. Web. 26 October 2011.
"Hypothyroidism (Underactive, Low Thyroid) WebMD: Symptoms, Causes and Treatments of
Hypothyroidism and Hypothyroid Disease." WebMD.com. 16 July 2010. Web. 28 October 2011.
Kunz, Marnie. "Exercise For Hypothyroid | LIVESTRONG.COM." LIVESTRONG.COM. 9 November 2010.
Web. 05 November 2011.
"New York Thyroid Center: Hypothyroidism." cpmcnet.columbia.edu. Web. 30 October 2011.
Norman, James, M.D. "Hypothyroidism: Symptoms and Treatments of Hypothyroid Disease - Part 1:
Introduction, Causes, and Symptoms of Hypothyroidism." EndocrineWeb.com. 7 July 2011.
Web. 26 October 2011.
Wardlaw, Gordon M., Anne M. Smith, and Alice K. Lindeman. Contemporary Nutrition: A Functional
Approach, Second Edition, Custom Edition for Salt Lake Community College. Dubuque, IA:
McGraw-Hill, 2011. Print.