and Dr. Sylvia Onusic, PhD

Cristina Fernandez, the President of Argentina, had her thyroid removed on January 4 only to find out the gland wasn't cancerous after all. Although her supporters whooped with joy at this news, doctors can't put it back, and Fernandez will be on thyroid meds for life.(1) Were her doctors incompetent or did they act appropriately? As that debate rages on over the internet, the Fernandez case has also led to widespread discussion of why thyroid cancer incidence, especially among women, has dramatically increased over the last 30 years.

AN EPIDEMIC OF THYROID CANCER

According to the National Cancer Institute, incidences of thyroid cancer have nearly doubled since the early 1970s. Thyroid cancer now affects about 11 people per 100,000 in the United States. In 2011, 56,460 new cases were diagnosed. In January 2008, there were 458,403 Americans alive who had a history of thyroid cancer, of which 100,952 were men and 357,451 women. In 2011, 56,460 new cases of thyroid cancer were diagnosed and 1,740 people died.(2, 3)

Doctors do not know why the numbers of thyroid cancer cases are increasing though some blame increased overweight and obesity, radiation exposure, and diets low in fruits and vegetables.

RADIATION

Certainly exposure to radiation is a known risk factor for thyroid cancer.(4) In 2009 epidemiologist Joseph Mangano, PhD, took data on thyroid cancer incidence from the Centers for Disease Control for the years 2001 to 2005, compared it the proximity of nuclear power stations, and found that the counties with the highest thyroid cancer incidence were located close together in eastern Pennsylvania, New Jersey, and southern New York. He concluded, "Exposure to radioactive iodine emissions from 16 nuclear power reactors within a 90 mile radius in this area . . . are likely a cause of rising incidence rates."(5) Pennsylvania has the highest rate of thyroid cancer in the U.S.

In 2010 the Associated Press revealed that 75 percent of U.S. nuclear power plants leak radioactive materials into our air and water.(6) And many of the 104 commercial nuclear power plants and 34 nuclear research stations now operating in the U.S. sit in seismically active locations, including at least four near the "high risk" San Francisco Bay Area and three within the area SFBA itself.(7) As might be expected, there is a high incidence of thyroid cancer in the San Francisco Bay Area.(8)

FRACKING

Radiation in ground water linked to fracking has also been linked to increasing rates. Fracking has also led to a 2,400 percent increase in earthquakes compared to the number of quakes that occurred in the years before fracking started in the US. (9,10) Geologist Tracy Bank, speaking at the American Geological Society meeting in Denver last November, reported that fracking releases rock-bound uranium, posing a further radiation risk to our groundwater. (11)

HORMONE HAVOC

Hormonal factors may also play a significant role, according to the National Cancer Institute. Although NCI arrived at this conclusion due to the preponderance of thyroid cancer cases in women under age 45, human estrogens should be regarded as just one piece of the hormonal picture. Xenoestrogens — estrogenic substances found in the diet and the environment — also play a role. Commonly found in plastics, pesticides, cosmetics, personal care products, our water supply, factory-farmed meats and soy foods, xenoestrogens can be significant "endocrine disruptors" and interfere with the functioning of many systems in the body.(12)

While it's human nature to try to single out one factor to blame, the causes of thyroid cancer most likely are many and synergistic. Exposure to radiation, mercury, fluoride, (13,14) plastics, pesticides, dioxins, solvents, low iodine intake,(15) and estrogens and estrogen mimickers found in commercial meats and produce, plastic and hormone replacement therapies have all been implicated. And so has soy.

SOY

Soy is widely marketed as a "health food" although soybeans naturally contain the phytoestrogens (plant estrogens) known as isoflavones. While not true hormones, isoflavones closely resemble estradiol (E2),(16) the most potent form of the three forms of estrogen found in the human body(17) and the form of estrogen that has been implicated in thyroid cancer.(18-20) Soy isoflavones cause significant endocrine disruption both directly and indirectly: directly by binding with estrogen receptors, and indirectly by interfering with the body's production of estrogen, testosterone and other hormones. The effects are felt throughout the body, especially the thyroid reproductive system, and are well documented in chapters 26 to 30 of The Whole Soy Story: The Dark Side of America's Favorite