Though we may not know how a lot of the toxic chemicals in today’s environments are affecting our health, science has discovered several links between toxic chemicals and thyroid disease or thyroid cancer.
What is the thyroid?
The thyroid gland, located in the front part of the neck, produces hormones that are responsible for regulating metabolism, growth and development, and organ function. If it’s overactive, it releases too much hormone, causing the body to use up energy faster than it should, which may result in irritability, fatigue, difficulty sleeping, and muscle weakness (hyperthyroidism). If it’s underactive, it produces too little hormone, and the body uses energy more slowly, which may result in weight gain and depression (hypothyroidism). Thyroid cancer, though highly survivable, often requires surgery.
The Toxic Chemicals Linked to Thyroid Problems
According to the American Cancer Society (ACS), thyroid cancer is one of the few types of cancer that’s on the rise, with the number of people diagnosed twice what it was in 1990. Though the organization attributes the increase partly to the use of thyroid ultrasound, which can detect small potential tumors, they admit that doesn’t fully explain the increase.
Science is finding that the hormones in the human body are particularly sensitive to toxic chemicals. Just like BPA (a chemical used in the manufacturing of plastics) can alter hormone function, other chemicals have been found to increase risk of thyroid problems.
Pesticides. The American Journal of Epidemiology published a study in 2010 that showed that women married to men who used pesticides in their daily work were at a much higher risk of developing thyroid disease than women in non-agricultural areas. The nonprofit group Beyond Pesticides warns that about 60 percent of pesticides used today may affect the thyroid gland’s production of hormones.
Perchlorate. According to a study published in the Journal of Occupational and Environmental Medicine, babies born with elevated levels of thyroid stimulating hormone-an indicator of thyroid disease-may have been affected by small amounts of perchlorate in the mother’s drinking water. Perchlorate is a chemical used to manufacture rockets, missiles, and fireworks. It may contaminate drinking water, crops irrigated by contaminated water, and milk and milk products from cows that graze on contaminated grasses. In 2004, the Environmental Working Group (EWG) found that levels of perchlorate in milk coming from California cows exceeded safety standards. In 2007, the Centers for Disease Control and Prevention (CDC) notified Congress of study results showing widespread human exposure, higher levels in children, and a connection between urine perchlorate levels and thyroid hormone levels.
Food colorings. Red 3 was recognized in 1990 by the FDA as a thyroid carcinogen in animals-it’s banned in cosmetics and externally applied drugs, but it’s still permitted in ingested drugs and foods.
Teflon. The EWG found that perfluorooctanoic acid (PFOA), a chemical used to make Teflon, food wrappers, and other products, may affect thyroid function even at moderate levels of exposure. A recent study published in Environmental Health Perspectives found that higher concentrations of PFOA are associated with current thyroid disease in the U.S. general adult population.
Phthalates, dioxins, and flame retardants: Though studies are still inconclusive on these chemicals, they have all been linked with thyroid disruption, and according to a study published in the European Journal of Endocrinology, “There is growing evidence that environmental chemicals can disrupt endocrine systems….Even small changes in thyroid homeostatis may adversely affect human health, and especially fetal neurological development may be vulnerable.”
How can you protect yourself? Keep making all the changes we talk about on this blog. Buy organic to reduce your exposure to pesticides, cook in pans not coated by Teflon, avoid food colorings (particularly red), filter your drinking water, and take my Ingredients to Avoid list with you shopping for personal care products. With a little extra care, you can help reduce your toxic exposure and increase your odds of staying healthy and happy.
Do you have some tips for keeping the thyroid healthy? Please share.
Whitney S. Goldner, et al., “Pesticide Use and Thyroid Disease Among Women in the Agricultural Health Study,” Am. J. Epidemiol. (2010) 171 (4): 455-464. http://aje.oxfordjournals.org/content/171/4/455.abstract.
Journal of Occupational and Environmental Medicine 2000; 42: 777
CDC Congressional Testimony, “Committee on Energy and Commerce Subcommittee on Environment and Hazardous Materials, United States House of Representatives, CDC’s Perchlorate Biomonitoring Activities and Study Results,” April 25, 2007. http://www.cdc.gov/washington/testimony/2007/t20070425a.htm.
Center for Science in the Public Interest (CSPI), “Food Dyes: A Rainbow of Risks.” http://www.cspinet.org/new/pdf/food-dyes-rainbow-of-risks.pdf.
Environmental Working Group, “Major Study of Teflon Chemical in People Suggest Harm to Immune System, Liver, Thyroid,” Press Release May 13, 2008. http://www.ewg.org/release/major-study-teflon-chemical-people-suggests-harm-immune-system-liver-thyroid.
Melzer D., et al., “Association Between Serum Perfluorooctanoic Acid (PFOA) and Thyroid Disease in the U.S. National Health and Nutrition Examination Survey,” Environ Health Perspect. 2010 May; 118(5): 686-92. http://www.ncbi.nlm.nih.gov/pubmed/20089479.
Malene Boas, et al., “Environmental Chemicals and Thyroid Function,” European Journal of Endocrinology (2006) 154: 599-611. http://www.eje.org/content/154/5/599.full.pdf.
Photo courtesy SabrinaSako via Flickr.com.