Threats to Thyroid Wellness
By Laurine Brown
October 2007

What's up with our thyroids? Why are so many women I counsel for nutritional issues at a local physician's office taking replacement thyroid hormones, I wonder? With some research, I learn that thyroid problems are surprisingly common - epidemic - across the country, affecting roughly 1 in 12 Americans. Of 13 million affected Americans, nearly 11 million are women (often failing during pregnancy and menopause), and more than half are undiagnosed, according to the Thyroid Foundation of America.

What is the thyroid? This butterfly-shaped gland located at the base of the neck, produces “thyroid hormones” (thyroxine T4 and trhiiodothyronine T3) which are grand master controllers for metabolism, energy levels, and prenatal development, including brain development. Hypothyroidism (low hormone level) is most common. Symptoms include fatigue, depression, dry skin, hair loss, cold hands and feet, difficulty concentrating and unexplained weight gain. Hyperthyroidism is far less common, indicating a hyperactive thyroid with nervousness, high blood sugar, problems sleeping and resulting fatigue. Dietary iodine is required to make these hormones. Historically, dietary iodine deficiencies fueled thyroid problems. Few foods naturally contain iodine (American's don't eat much seaweed), and because soils in upper Midwest and Great Lakes region were iodine-poor, this area was known as the “Goiter Belt” before we iodized salt (goiter is enlarged thyroid caused by too much or too little iodine.) While globally iodine deficiencies are still common, most Americans get more than enough through fortified salt, seafood, and now even flour, and dairy products containing iodine added to cattle feed and for sanitizing.

So if our diet is plentiful in iodine, what else could be causing this? We know that genetics plays a role, but since our genes haven't changed much over the past few decades, that doesn't explain the epidemic.

Exposure to x-rays and other forms of ionizing radiation (like nuclear power plant emissions and fallout from atomic bomb testing) are now known causes of thyroid cancer and likely contribute significantly to dysfunction. From 1930 to 1980, millions of Americans were x-rayed from head to toe without protection from “scatter” for numerous conditions including acne, bronchitis, scalp ringworm, even thyroid conditions and shoe-size fittings! Only recently have we wisened-up, arming ourselves with lead vest shields, and now 10-40 years later we are paying for earlier exposures. We also know thyroid cancers and other problems are more common in the fallout path from Chernobyl, Hiroshima, and Nevada nuclear testing sites. Additionally, clues are emerging that everyday chemicals that sweeten our life with fragrance, repel stains, retard flames, soften plastics, and line our food cans may be wreaking havoc with thyroid function (see box below). These substances get inside our bodies when we eat contaminated food or water, breathe them into our lungs, or rub them on our skin, and are of special concern to young and unborn children. Some may block iodine or essential enzymes needed to make thyroid hormones. Others may act as thyroid hormone imposters scrambling messages. Or they may slow-up or too-swiftly hasten the thyroid hormone's destruction. We're only beginning to understand “if” and “how” various substances may sabotage our thyroids, but these clues offer pathways for protection from harm.

Some Suspected Thyroid-Altering Chemical Culprits
o Flame retardants polybrominated diphenyl ethers (PBDEs) in carpets, computer plastics, even children's pajamas.
o Non-stick, stain-resistant, slippery chemicals perfluorooctanoic acid (PFOA) used in non-stick cookware, stain-resistant clothes, microwave popcorn bags and more.
o Rocket fuel's oxygen source perchlorate contaminates drinking water especially in southwestern US. EPA is in the process of setting drinking water standards.
o Old electrical insulation polychlorinated byphenyls (PCBs) which, though banned, are disturbingly persistent, accumulating up the food chain in animal fat including our own fat.
o Fungicides ethylenebisdithiocarbamates (EBDCs) used on many plants like roots, leafy vegetables, fruit, cereals.
o Plasticizers phthalates used to soften vinyl plastics like toys, tablecloths, IV bags and also stabilize fragrances in many personal products (often not labeled). Also, bisphenol A (BPA) found in some plastics and resins of dental sealants, white canned-food liners.
o Flouride added to drinking water to prevent dental caries and chlorine to disinfect; both are chemically related to iodine and may block it's important functions.
o Antibacterial triclosan added to soaps.


Thyroid Wellness - What Can You Do?
Ask your doctor to test your thyroid function with a simple blood test, if you suspect you have a problem.

Avoid unnecessary x-rays. Ask, is this necessary? During dental and other x-rays be sure your thyroid is covered with a protective apron. And keep your distance from nuclear power plants and other possible sources of “ionizing” radiation.

Nourish your thyroid with plenty of plant foods (like a colorful assortment of vegetables, fruits, nuts, seeds, whole grains). Many nutrients found in these plant foods support thyroid hormone actions, e.g., B-complex, copper, antioxidants, selenium, L-tyrosine. (Note: some nutritious plants act as goitrogens inhibiting production of thyroid hormones - like broccoli, cabbage, cauliflower, kale, spinach, soybeans, turnips, pears , peaches - but cooking usually inactivates them.) Since some pollutants (like PCBs) concentrate in animal fat, choose lean meats like fish or chicken and lowfat dairy. And choose organic foods when possible which limits suspect fungicides/pesticides.

Exercise regularly. Among its many benefits, it can help boost metabolism, mood, and cleanse the body of stored pollutants that clog thyroid function.

Check your local water supply for pollutants like perchlorate and filter them out.

Educate yourself on suspect chemical culprits in everyday products and choose safer products or simply enjoy “doing without.” For example, choose stainless steel cookware over non-stick, forgo flame retardant and stain resistant coatings and microwave popcorn, and find phthalate-free plastics and cosmetics. See www.greenguide.com for lots of tips.

References
Brown V. Disrupting a Delicate Balance: Environmental Effects on the Thyroid. Environmental Health Perspectives. September 2003. 111(12):A642-649 <www.ehonline.org/docs/2003/111-12/focus-abs.html>

Zandonella C. Environmental Thyroid Threats. The Green Guide. Sept/Oct 2007. #122 <www.thegreenguide.com/doc/122/thyroid>

Educational Services, Inc. Thyroid Disease. Complementary Therapy-Gram. June 2002. Volume 5(3):1-5.