Updated September 05, 2011
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Fluoride in toothpaste may have an effect on thyroid health.
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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?
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.
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.
Studies dating back to the 1950s have shown links between Down's
Syndrome and natural fluoridation. Ionel Rapaport also showed how the
age of women bearing Down's Syndrome children decreased in direct
relation to the increase of fluoride in the water supply. The more
fluoride that was in the water, the younger the age of the women bearing
Down's Syndrome children.
Even those who aren't convinced of the toxicity of fluoride should be concerned about the level of fluoride added to the water supply. The optimum level was set in the 1940s at approximately 1 ppm (equal to 1 mg/l). This was based on assumptions that the total intake of fluoride would be 1 mg/day, assuming 4 glasses of water were drunk per day. However, current intake of fluoride comes not just from the water supply. A study conducted by researchers at the University of Iowa and reported in the November issue of the Journal of American Dental Association found that 71% of more than 300 soft drinks contained 0.60 ppm fluoride. Toothpaste, beverages, processed food, fresh fruits and vegetables, vitamins and mineral supplements all contribute to the intake of fluoride. It is now estimated that the total amount of fluoride ingested per day is 8 mg/day, eight times the optimum levels.
An additional and less well studied concern is the interaction of the fluoride compounds added to water with other water additives. Most studies examining the addition of fluoride to water have used sodium fluoride, however, most communities use the less expensive forms such as silicofluoride, hydrofluosilicic acid or sodium silicofluoride. A 1999 study of 280,000 Massachusetts children shows that levels of lead in blood were significantly higher in communities using these cheaper compounds than in towns where sodium fluoride was used or where the water was not treated at all. ("Children's Health and the Environment", 17th International Neurotoxicology Conference, Little Rock, Arkansas, October 17-20, 1999).
Aluminum compounds are frequently added to the water supply as clarifying agents. On its own, aluminum is not readily absorbed by the body, however, when fluoride is present, the two form aluminum-fluoride, which is easily absorbed. A long term study published in 1988 found that even low levels of aluminum-fluoride in drinking water delivered more aluminum to the brain than concentrated aluminum fluoride. The same study found that low levels of aluminum fluoride and sodium fluoride found in "optimally" fluoridated water cause severe kidney damage and lesions to the brain similar to those found in Alzheimer's and other forms of dementia. Dr. Robert Isaacson, State University of New York, found that when aluminum fluoride is added to the food of rats, the rats developed short-term memory problems, smell sensory loss and other characteristics of Alzheimer's disease. (Isaacson, R. "Rat studies link brain cell damage with aluminum and fluoride in water" State Univ. of New York, Binghampton, NY, Wall Street Journal article by Marilyn Chase; Oct. 28, 1992, p. B-6).
What are the Thyroid-Specific Concerns?
Is fluoride in part the reason for near epidemic levels of hypothyroidism in the United States? Some experts and researchers believe this is the case.
Fluoride had been used for decades as an effective anti-thyroid medication to treat hyperthyroidism and was frequently used at levels below the current "optimal" intake of 1 mg/day. This is due to the ability of fluoride to mimic the action of thyrotropin (TSH). It makes sense, then that out of the over 150 symptoms and associations of hypothyroidism, almost all are also symptoms of fluoride poisoning.
Researcher and advocate Andreas Schuld has also found that excess of fluoride correlates with other thyroid-related issues such as iodine deficiency. Fluoride and iodine, both being members of the halogens group of atoms, have an antagonistic relationship. When there is excess of fluoride in the body it can interfere with the function of the thyroid gland. It is possible that iodine deficiency, which is the most common cause of brain damage and mental disability in the world, could be lessened by simply cutting back on the use of fluoride.
Even those who aren't convinced of the toxicity of fluoride should be concerned about the level of fluoride added to the water supply. The optimum level was set in the 1940s at approximately 1 ppm (equal to 1 mg/l). This was based on assumptions that the total intake of fluoride would be 1 mg/day, assuming 4 glasses of water were drunk per day. However, current intake of fluoride comes not just from the water supply. A study conducted by researchers at the University of Iowa and reported in the November issue of the Journal of American Dental Association found that 71% of more than 300 soft drinks contained 0.60 ppm fluoride. Toothpaste, beverages, processed food, fresh fruits and vegetables, vitamins and mineral supplements all contribute to the intake of fluoride. It is now estimated that the total amount of fluoride ingested per day is 8 mg/day, eight times the optimum levels.
An additional and less well studied concern is the interaction of the fluoride compounds added to water with other water additives. Most studies examining the addition of fluoride to water have used sodium fluoride, however, most communities use the less expensive forms such as silicofluoride, hydrofluosilicic acid or sodium silicofluoride. A 1999 study of 280,000 Massachusetts children shows that levels of lead in blood were significantly higher in communities using these cheaper compounds than in towns where sodium fluoride was used or where the water was not treated at all. ("Children's Health and the Environment", 17th International Neurotoxicology Conference, Little Rock, Arkansas, October 17-20, 1999).
Aluminum compounds are frequently added to the water supply as clarifying agents. On its own, aluminum is not readily absorbed by the body, however, when fluoride is present, the two form aluminum-fluoride, which is easily absorbed. A long term study published in 1988 found that even low levels of aluminum-fluoride in drinking water delivered more aluminum to the brain than concentrated aluminum fluoride. The same study found that low levels of aluminum fluoride and sodium fluoride found in "optimally" fluoridated water cause severe kidney damage and lesions to the brain similar to those found in Alzheimer's and other forms of dementia. Dr. Robert Isaacson, State University of New York, found that when aluminum fluoride is added to the food of rats, the rats developed short-term memory problems, smell sensory loss and other characteristics of Alzheimer's disease. (Isaacson, R. "Rat studies link brain cell damage with aluminum and fluoride in water" State Univ. of New York, Binghampton, NY, Wall Street Journal article by Marilyn Chase; Oct. 28, 1992, p. B-6).
What are the Thyroid-Specific Concerns?
Is fluoride in part the reason for near epidemic levels of hypothyroidism in the United States? Some experts and researchers believe this is the case.
Fluoride had been used for decades as an effective anti-thyroid medication to treat hyperthyroidism and was frequently used at levels below the current "optimal" intake of 1 mg/day. This is due to the ability of fluoride to mimic the action of thyrotropin (TSH). It makes sense, then that out of the over 150 symptoms and associations of hypothyroidism, almost all are also symptoms of fluoride poisoning.
Researcher and advocate Andreas Schuld has also found that excess of fluoride correlates with other thyroid-related issues such as iodine deficiency. Fluoride and iodine, both being members of the halogens group of atoms, have an antagonistic relationship. When there is excess of fluoride in the body it can interfere with the function of the thyroid gland. It is possible that iodine deficiency, which is the most common cause of brain damage and mental disability in the world, could be lessened by simply cutting back on the use of fluoride.
The Future of Fluoride
Some advocates believe that the truth about fluoride does not reach the public easily because fluoride, produced as a toxic waste byproduct of many types of heavy industry - such as aluminum, steel, fertilizer, glass, cement and other industries -- must be disposed of somewhere. If it's not used as an additive to water, manufacturers would have to pay millions of dollars to dispose of it properly, so the pressure to keep fluoride listed as a healthy additive to water-and not as an environmental toxin that requires costly disposal - is great and political pressures to keep fluoride in the drinking water is strong.
And the U.S. government has been one of the key supporters for fluoridation. Despite the questions regarding fluoride's effectiveness and safety, the administration's stated federal health objective is to increase the number of Americans with fluoridated tap water from previous levels of 62 percent to 75 percent in 2000.
Given half a century of support for fluoridation, it's also not likely that the American Dental Association will backtrack on its support for fluoridation.
Some cities are taking action, and making the decision to stop fluoridating their water supply - or not to fluoridate in the first place. For example, the City Council of Santa Barbara, California voted in late November of 1999 in favor of a resolution that "disagrees with and rejects the State's recommendation to fluoridate the city's public water system." With this action Santa Barbara joined the California cities of Santa Cruz, El Cajon, La Mesa, Escondido and Helix, Riverview, and Lakeside water districts that have each passed protective resolutions or ordinances in 1999. The cities of San Diego and Sunnyvale have ordinances prohibiting fluoridation that pre-date the State's law. The city officials of Santa Barbara indicated that adding a chemical to the water supply to medicate everyone was not the right approach and requested that the City's staff look into other programs to help children obtain fluoride for dental health.
The only admission that you're likely to see is the 1997 addition of warnings on toothpaste tubes, that now say: "Don’t Swallow—Use only a pea-sized amount for children under six." and "Children under six should be supervised while brushing with any toothpaste to prevent swallowing." In areas where the drinking water already contains fluoride, brushing more than once daily with more than a pea-sized amount of fluoridated toothpaste can cause fluorosis, the discoloration and spotting of the teeth that affects an estimated 20% of children.
What Can You Do?
Besides learning more about the effects of fluoride and getting involved in your community's decisions regarding water fluoridation, you can buy an unfluoridated, natural toothpaste, such as Tom's of Maine, particularly for young children.
You can also pay attention to the water you drink, and use filtered or bottled waters. Some water filters can remove fluoride from the water, but carbon-based filters such as the Brita filter do not, so be sure to find the right type of filter for fluoride.
Many bottled waters contain no additional fluoride. You can find out the fluoride and other mineral content of your favorite bottled waters at Bottled Water Web's Bottlers listing. Evian and Calistoga brands, for example, contain no measurable fluoride, but Perrier has 0.12 parts per million.
Some advocates believe that the truth about fluoride does not reach the public easily because fluoride, produced as a toxic waste byproduct of many types of heavy industry - such as aluminum, steel, fertilizer, glass, cement and other industries -- must be disposed of somewhere. If it's not used as an additive to water, manufacturers would have to pay millions of dollars to dispose of it properly, so the pressure to keep fluoride listed as a healthy additive to water-and not as an environmental toxin that requires costly disposal - is great and political pressures to keep fluoride in the drinking water is strong.
And the U.S. government has been one of the key supporters for fluoridation. Despite the questions regarding fluoride's effectiveness and safety, the administration's stated federal health objective is to increase the number of Americans with fluoridated tap water from previous levels of 62 percent to 75 percent in 2000.
Given half a century of support for fluoridation, it's also not likely that the American Dental Association will backtrack on its support for fluoridation.
Some cities are taking action, and making the decision to stop fluoridating their water supply - or not to fluoridate in the first place. For example, the City Council of Santa Barbara, California voted in late November of 1999 in favor of a resolution that "disagrees with and rejects the State's recommendation to fluoridate the city's public water system." With this action Santa Barbara joined the California cities of Santa Cruz, El Cajon, La Mesa, Escondido and Helix, Riverview, and Lakeside water districts that have each passed protective resolutions or ordinances in 1999. The cities of San Diego and Sunnyvale have ordinances prohibiting fluoridation that pre-date the State's law. The city officials of Santa Barbara indicated that adding a chemical to the water supply to medicate everyone was not the right approach and requested that the City's staff look into other programs to help children obtain fluoride for dental health.
The only admission that you're likely to see is the 1997 addition of warnings on toothpaste tubes, that now say: "Don’t Swallow—Use only a pea-sized amount for children under six." and "Children under six should be supervised while brushing with any toothpaste to prevent swallowing." In areas where the drinking water already contains fluoride, brushing more than once daily with more than a pea-sized amount of fluoridated toothpaste can cause fluorosis, the discoloration and spotting of the teeth that affects an estimated 20% of children.
What Can You Do?
Besides learning more about the effects of fluoride and getting involved in your community's decisions regarding water fluoridation, you can buy an unfluoridated, natural toothpaste, such as Tom's of Maine, particularly for young children.
You can also pay attention to the water you drink, and use filtered or bottled waters. Some water filters can remove fluoride from the water, but carbon-based filters such as the Brita filter do not, so be sure to find the right type of filter for fluoride.
Many bottled waters contain no additional fluoride. You can find out the fluoride and other mineral content of your favorite bottled waters at Bottled Water Web's Bottlers listing. Evian and Calistoga brands, for example, contain no measurable fluoride, but Perrier has 0.12 parts per million.
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