Fluoride in toothpaste may have an effect on thyroid health.
This common additive to your water supply, and ingredient in the toothpaste you and your children use may be contributing to the increased rates of hypothyroidism -- and other health concerns -- in the U.S. . . without improving dental health
What is Fluoride?
Fluoride is an element from the halogen group, as are iodide and chloride. It is commonly added to the water supply as hydrofluosilicic acid, silicofluoride or sodium fluoride. Fluoride is also found as an additive in toothpastes and some mouthwashes, as a tooth decay preventive ingredient.
Why is Fluoride Used?
Fluoride is used to fight tooth decay in children. The key initial studies purporting to demonstrate its effectiveness as an anti-cavity fighting compound were performed back in the 1940s. Those studies, conducted in Grand Rapids, MI in 1945, in Newburgh, NY in 1945, in Brantford, Ontario in 1945, and in Evanston, IL in 1947, are now being called into question. According to Dr. Philip Sutton, author of "The Greatest Fraud: Fluoridation" *A Factual Book, Lorne, Australia, 1996), these studies are actually of dubious scientific quality.
More recently, other studies attempting to document the effectiveness of fluoride have been conducted. Dr. John Yiamouyiannis examined the raw data from a large study that was conducted by the National Institute for Dental Research (NIDR). He concluded that fluoride did not appear to have any decay preventing success, as there was little difference in the DMFT values (the mean number of decayed, missing or filled teeth) for approximately 40,000 children. It did not matter whether they grew up in fluoridated, non-fluoridated or partially fluoridated communities. (Yiamouyiannis, J.A. "Water Fluoridation and Tooth Decay: Results from the 1986-87 National Survey of U.S. Schoolchildren", Fluoride, 23, 55-67, 1990).
A larger study has been conducted in New Zealand. There, the New Zealand National Health Service plan examines the teeth of every child in key age groups, and have found that the teeth of children in non-fluoridated cities were slightly better than those in the fluoridated cities. (Colquhoun, J. "Child Dental Health Differences in New Zealand", Community Healthy Services, XI 85-90, 1987).
Although children's teeth have improved steadily from the 1930s to the 1990s, this improvement appears to be independent of the addition of fluoride to the water. A study has yet to be conducted that specifically addresses whether the addition of fluoride affects the quality of teeth, while controlling and accounting for other factors and other sources of fluoride.
Despite growing questions about the effectiveness of using fluoride to fight tooth decay - and increasing concerns of the safety of this practice -- over 60 percent of the United States' water supply is fluoridated. Most of those cities are in the eastern part of the U.S.
What are the Concerns Associated with the Addition of Fluoride to the Water Supply?
The most recognized problem with the ingestion of too much fluoride is dental fluorosis. This condition is characterized by the failure of tooth enamel to crystallize properly in permanent teeth. The effects range from chalky, opaque blotching of teeth to severe, rust-colored stains, surface pitting and tooth brittleness.
This condition, though worrisome, may not be the key concern , at least according to some researchers. Dr. Phyllis Mullenix believes, based on her research, that fluoride acts in a way that lowers the I.Q. of children ("Neurotoxicity of Sodium Fluoride in Rats", Mullenix, P. Neurotoxicology and Teratology, 17 (2), 1995).
Dr. William Marcus, believes that a study conducted by Battelle for the National Toxicology Program on the toxicology of fluoride shows that there were dose-related increases in bone cancer in male rats. Dr. Marcus also questions the removal by peer reviewers of cancers at other sites in the rats as well. Especially worrisome to Dr. Marcus is the fact that that levels of fluoride that caused the cancers in the rats were lower than those seen in humans who ingested lower amounts, but for a longer period. These levels are generated because fluoride is accumulated in the body and is not secreted.
Dr. Marcus was formerly the chief toxicologist for the EPA's Office of Drinking Water, but was fired in 1991 after insisting that an unbiased evaluation of fluoride's cancer potential be conducted. Marcus fought his dismissal, and was able to be reinstated after demonstrating in court that it was politically motivated.
An article in the Irish Times of Dublin on August 16, 1999, reports that Dr. Hans Moolenburgh's research in Holland found that up to 4 percent of people using fluoridated water experienced health problems. These problems ranged from gastrointestinal disorders to mouth sores to rashes to headaches to forms of arthritis to more serious concerns such as cancers and neurological complaints.