(Autoimmune or Hashimoto's Thyroiditis)
The hormones produced by the thyroid regulate metabolism in every cell. Hypothyroidism is the result of inadequate thyroid functioning, with reduced amounts of the thyroid hormone available. Thyroid hormone governs the rate at which many physiological functions take place in the body. Thyroiditis is the most common cause wherein inflammation and swelling damage the thyroid and may arise from a variety of triggers.
- Iodine: Iodine is required by the body to form thyroid hormones, and iodine deficiency can lead to goiter and hypothyroidism. Today, most cases of iodine deficiency occur in developing nations. In industrialized countries where iodized salt is used, iodine deficiency has become extremely rare. Excessive iodine intake can result in either hypothyroidism or hyperthyroidism (overactive thyroid). Sources of iodine include foods (iodized salt, milk, water, seaweed, ground beef), dietary supplements (multiple vitamin/mineral formulas, seaweed extracts), drugs (potassium iodide, amiodarone, topical antiseptics), and iodine-containing solutions used in certain laboratory tests. Many nutritional supplements contain 150 mcg of iodine. While that amount of iodine should prevent a deficiency, it is not clear whether supplementing with iodine is necessary or desirable for most individuals.
- Avoid goitrogens, chemicals that can enlarge the thyroid and interfere with thyroid hormone production. These include: canola oil, uncooked cabbage family vegetables1, cassava, corn, sweet potatoes, lima beans, soy and pearl millet. It is recommended that these be avoided but no research suggests that they cause hypothyroidism.
Thyroid extracts are available as nutritional supplements in capsules and tablets. As thyroid extract is not an essential nutrient, therefore, no deficiency state exists. The recommended intake depends on the concentration, method of preparation, and quality of the thyroid extract. Follow the manufacturer's recommendation on the label.
No side effects or adverse reactions have been reported. However, people taking prescription thyroid hormones should consult their doctor before using non-prescription thyroid extracts.
While natural therapies may help to some extent, thyroid hormone replacement is necessary for most people with hypothyroidism.
The medical treatment of hypothyroidism usually involves a prescription of synthetic thyroid hormones thyroid extract. The difference between prescription thyroid extract and the thyroid extracts sold as nutritional supplements, is that extracts are required by the U.S. FDA to be free of known active thyroid hormones (thyroxine and triiodothyronine) which can cause significant health issues such as heart rate increase, heart irregularities, nervousness, palpitations and diarrhea.2 Use of these hormone-free thyroid preparations has not been evaluated in scientific studies, but some doctors believe these products may provide nutritional support to the thyroid gland or contain other compounds with possible hormonal activity.
Hypothyroidism symptoms can be different for each individual, but often include several of the these:
- Feeling fatigue, "slowed down", lethargy
- Increased sensitivity to cold
- Constipation or hard stool
- Weight gain
- Sadness or depression
- Heavy menstruation
- Dry skin or dry, brittle fingernails
- Muscle or joint pain
If early symptoms are not treated then additionally hoarseness, decreased sense of taste and smell, puffy hands, feet, face, slow speech, skin thickens, or eyebrows getting thinner may result.
For most of us there is more than one trigger for low thyroid function. Medical treatment, including radiation or surgery may damage the thyroid. Hashimoto's thyroiditis is a thyroid gland autoimmune disease. Secondary hypothyroidism results from iodine deficiency.
- Family history and congenital birth defects
- Respiratory infections
- Drugs including lithium and amiodarone
- Yoyo dieting and nutrient deficient diets
- Chronic high stress
- Radiation treatment or surgical removal of all or part of thyroid.
- Hormonal changes (puberty, childbirth, menopause)
- High levels of soya consumption
- Physical injury to thyroid
- Lead poisoning
- Exposure to polybrominated biphenyls (PBBs in flame retardants in plastics)
- Exposure to carbon disulfide (used in fumigation, insecticides, solvents, and manufacturing processes
Medical professionals generally prescribe synthetic thyroid hormones such as levothyroxine.
- Goiter is an enlarged thyroid gland and can also result in hypothyroidism. It can be triggered by iodine deficiency or by eating foods with goiter-causing substances. In many cases, the cause of goiter cannot be determined.
- Myxedema coma, the most severe form of hypothyroidism, is rare.
- Glaucoma Thyroid problems have been linked to glaucoma in a 2002 study.
- Sheehan syndrome occurs in women who bleed heavily during pregnancy or childbirth resulting in damage to pituitary.
1. McMillan M, Spinks EA, Fenwick GR. Preliminary observations on the effect of dietary brussel sprouts on thyroid function. Hum Toxicol 1986;5:15-9