There is clear evidence that small amounts of fluoride, at or near levels added to U.S. water supplies, present potential risks to the thyroid gland, according to the National Research Council’s (NRC) first-ever published review of the fluoride/thyroid literature.(A)

Fluoride, in the form of silicofluorides, injected into 2/3 of U.S. public water supplies, ostensibly to reduce tooth decay, was never safety-tested.(B)

“Many Americans are exposed to fluoride in the ranges associated with thyroid effects, especially for people with iodine deficiency,” says Kathleen Thiessen, PhD, co-author of the government-sponsored NRC report. “The recent decline in iodine intake in the U.S could contribute to increased toxicity of fluoride for some individuals,” says Thiessen.

“A low level of thyroid hormone can increase the risk of cardiac disease, high cholesterol, depression and, in pregnant woman, decreased intelligence of offspring,” said Thiessen.(C)

Common thyroid symptoms include fatigue, weight gain, constipation, fuzzy thinking, low blood pressure, fluid retention, depression, body pain, slow reflexes, and more. It’s estimated that 59 million Americans have thyroid conditions.(D)

Robert Carton, PhD, an environmental scientist who worked for over 30 years for the U.S. government including managing risk assessments on high priority toxic chemicals, says “fluoride has detrimental effects on the thyroid gland of healthy males at 3.5 mg a day. With iodine deficiency, the effect level drops to 0.7 milligrams/day for an average male.”(E) (1.0 mg/L fluoride is in most water supplies)

Among many others, the NRC Report cites human studies which show

- fluoride concentrations in thyroids exceeding that found in other soft tissues except kidney

- an association between endemic goiter and fluoride exposure or enamel fluorosis in human populations

- fluoride adversely affects thyroid and parathyroid hormones, which affect bone health

“If you have a thyroid problem, avoiding fluoride may be a good preventive health measure for you,” writes Drs’ Richard and Karilee Shames in “Thyroid Power.”(F).

Scientific American quotes John Doull, professor emeritus of pharmacology and toxicology at the University of Kansas Medical Center, who chaired the NRC committee , “The thyroid changes do worry me.”

References:

(A) "Fluoride in Drinking Water: A Scientific Review of EPA's Standards," Committee on Fluoride in Drinking Water, Board on Environmental Studies and Toxicology, Division on Earth and Life Studies, National Research Council of the National Academies of Science. March 2006 Chapter 8

http://www.nap.edu/catalog.php?record_id=11571

"Thyroid Function: Fluoride exposure in humans is associated with elevated TSH concentrations, increased goiter prevalence, and altered T4 and T3 concentrations." (Page 262)

"(The thyroid effects are associated with average fluoride intakes that) will be reached by persons with average exposures at fluoride concentrations of 1-4 mg/L in drinking water, especially the children." (Page 260)

(B) Sodium Hexafluorosilicate and Fluorosilicic Acid

Review of Toxicological Literature, October 2001

http://ntp.niehs.nih.gov/ntp/htdocs/Chem_Background/ExSumPDF/Fluorosilicates.pdf

(C) Chemical & Engineering News, “Fluoride Risks Are Still A Challenge,” by Bette Hileman, September 4, 2006,

http://pubs.acs.org/cen/government/84/8436gov1.html

(D) Mary Shomon, About.com Thyroid editor, Patient Advocate -- Author of "The Thyroid Diet" and "Living Well With Hypothyroidism"

http://thyroid.about.com/

(E) Fluoride, “Review of the 2006 National Research Council Report: Fluoride in Drinking Water,” July-September 2006, by Robert J. Carton

http://www.fluorideresearch.org/393/files/FJ2006_v39_n3_p163-172.pdf

(F) Thyroid Power and Feeling Fat Fuzzy or Frazzeled“by Richard Shames MD & Karilee Shames RN, PhD http://www.thyroidpower.com http://www.feelingfff.com/

Fluoride/Thyroid Health Effects

http://www.fluoridealert.org/health/thyroid/

Sources of Fluoride

http://www.fluoridealert.org/f-sources.htm

Sulfuryl Fluoride Pesticide Residues Allowed on Foods

http://www.fluoridealert.org/pesticides/sulfuryl.f.all.food.html

United States Department of Agriculture (USDA) National Fluoride Database of Selected Beverages and Foods

http://www.nal.usda.gov/fnic/foodcomp/Data/Fluoride/Fluoride.html