To Your Health
May, 2011 (Vol. 05, Issue 05) |
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Autoimmunity and Food Sensitivities
Autoimmunity is another leading cause of hypothyroidism. Autoimmune destruction of thyroid tissue, known as Hashimoto's thyroiditis, occurs primarily in women and older adults between the ages of 45-65.
These patients express antibodies to the enzyme thyroid peroxidase. Hashimoto's, much like other autoimmune diseases, appears to correlate highly with
food intolerances such as celiac disease.
Other Dietary Influences on Thyroid Health
In addition to gluten, other foods known as goitrogens have been shown to be damaging to thyroid function. There are two main classes of food goitrogens: cruciferous vegetables (broccoli, cauliflower, cabbage) and soybean-related foods. Both isothiocyanates from cruciferous vegetables and soy isoflavones have an inhibitory effect on thyroid peroxidase and interfere with iodine uptake by the thyroid gland. In a metabolic experiment, rats fed a daily diet of moderate iodine intake and 25 mg of thiocyanate (a known goitrogen), showed significant reduction in circulating thyroxine after 60 days. If you have a diagnosed iodine deficiency, you should talk to your doctor about whether reducing your intake of uncooked cruciferous vegetables, particularly while taking iodine supplements, is a wise course of action.
Concerns also continue to grow about the excessive consumption of genetically modified soy-based foods by thyroid patients. While moderate intake of traditional soy foods (tempeh, edamame, etc.) has been shown to provide some health benefits, it is argued that the negative effects on the thyroid may be enhanced by the genetic modification process. In addition to these foods, certain xenobiotic toxins including phthalate esters (substances added to plastics to increase their flexibility, transparency, durability and longevity), polychlorinated bisphenyls (PCBs, which were banned in 1979 but still may be present in older paints, plastics, floor finishes, adhesives, tapes and other items), and polycyclic aromatic hydrocarbons (pollutants present in oil, coal and tar deposits, among other items) have all been shown to produce goitrogenic effects.
Keep Your Body in Motion
Undiagnosed hypothyroidism is a common and clinically significant health problem that affects millions of Americans. Could you be one? If you find yourself expressing symptoms of low thyroid activity, talk to your doctor, who may run tests to check your TSH and T3/T4 levels. And keep in mind that while less common than hypothyroidism, you can also experience hyperthyroidism: an overactive thyroid that releases too much hormones instead of too little. Symptoms of hyperthyroidism can include weight loss, increased appetite, nervousness, restlessness, weakness, itching, nausea and vomiting, among other unpleasantries. Talk to your doctor about thyroid health and learn more about how to keep your body in motion.
Thyroid 101
What It Is: A butterfly-shaped gland located in the front part of the neck just below the voice box (larynx).
What It Does: The thyroid gland's major function is to modulate the metabolic rate - the speed at which your body utilizes energy. Thyroid hormones regulate metabolism and affect the growth and rate of function various systems throughout the body.
How It Does It: Thyroid activity is stimulated by the pituitary gland, which secretes thyroid stimulating hormone (TSH) to signal the production of thyroxine in the thyroid. There are two many thyroid hormones: T3 (triiodothyronine) and T4 (tetraiodothyronine).
What Can Happen If It Doesn't Function Properly (commonly hypothyroidism):*
Early Symptoms
- Sensitivity to cold
- Constipation
- Depression
- Fatigue or lethargy
- Heavier menstrual periods
- Joint or muscle pain
- Pale or dry skin
- Thin, brittle hair or fingernails
- Weight gain
Late Symptoms (if left untreated)
- Decreased taste and smell
- Hoarseness
- Puffy face, hands, and feet
- Slow speech
- Thickening of the skin
- Thinning of eyebrows
Clair Whiteman, BSc, received her degree in nutrition and dietetics from Bastyr University in Washington state. She is currently the on-staff nutritionist for BioGenesis Nutraceuticals, a professional-grade supplement line.
