Health - Fluoride

Note: This page is still a work in progress and may be missing sources.

For thousands of years humans died from tooth decay. Tooth decay occurs when bacteria eats up our left over sugary foods (fruits, etc) and leave behind acids. Over time these acids will destroy tooth enamel, which is the hard outer layer of a tooth. This opens holes for more bacteria to crawl inside and disperse more acid. This is how teeth decay. (1) For a long time dentistry was more of an art than a science. Pulling out teeth and prescribing herbs for pain relief was about as complex a dentist's job would get up until the 18th century. Horace Wells, a Connecticut dentist, discovered that nitrous oxide could be used to render patients unconscious. (2)  (Finally those teeth could be yanked out without feeling it) Other methods and practices developed such as filling cavities with gold, large productions of toothbrushes and toothpaste. Toothpaste started off as simple mixtures of chalk and soap, but in 1896, Colgate Dental Cream was introduced which included Sodium Lauryl Sulphate and Sodium Ricinoleate as ingredients. (3)

In the 1930's a Colorado dentist named Frederick S. McKay became convinced that the origins of brown stains on his patients’ teeth were connected to their local water supply. McKay’s research verified that drinking water with high levels of naturally occurring fluoride was associated  with mottled enamel.(Brown spots on teeth)  By the early 1940s, H. Trendley Dean determined that taking out the right amount of fluoride would both eliminate the mottling problem and prevent tooth decay. In 1945, Newburgh, New York, and Grand Rapids, Michigan would all regulate sodium fluoride in their water systems. A lot of citizens, unaware that fluoride naturally exists in rivers and springs, feared that this was a health risk and an obstruction of personal choice. Reflecting on the past 50 years dozens of epidemological studies from around the world indicate that water fluoridation is both effective in preventing tooth decay and very safe. (4) Water fluoridation has been considered by the Center of Disease control to be one of the top ten public health achievements for the 20th century. (5) Why do people still doubt the safety of fluoride?

Humans should not consume Fluoride. It is a toxin and its unnatural

The saying goes, it’s the dose that makes the poison. Yes Fluoride is toxic if you consume too much of it, but so is water, vitamin D, calcium or virtually any kind of vitamin. To say its unnatural is flat out false. It exists naturally in water and in much higher traces! As explained in the brief history section, one of the reasons for the many cases of brown spots and fluorosis (changes in teeth formation) was because there was too much natural fluoride in the water supply. The amount of fluoride in the water supply has been reduced since the 1950’s to an optimal amount of 0.1-1.2 ppm depending on where you live. How much fluoridated water would you have to drink before you die from toxicity? It is actually impossible to consume the amount required. You would need to in get 5-10 grams at one time. This is 10,000 times the amount of fluoride is an 8 oz cup of fluoridated water. (1) But what about the amount in toothpaste? This is something I had worries about until I did the math. While I am not mathematician, I have estimated that the lethal dosage for toothpaste to be around an entire tube! This obviously does not mean that you should eat toothpaste. Consuming too much toothpaste can result in fluorosis.

Fluoridated water causes cancer

50 epidemiological studies done in different populations at different times have failed to demonstrate an association. These studies were done by the United States, Japan, the UK, Canada and Australia. (5) This assertion arises from a flawed study from the 1970's comparing cancer rates in 10 large fluoridated cities versus ten large nonfluoridated cities. The National Cancer Institute concluded that the study was flawed for numerous methodological reasons. A review by other researchers concluded that the level of industrialization was much higher in the fluoridated cities than the nonfluoridated. (6) There are known cancer threats with factories and pollution and this seems to fit the data much better than fluoridation. Although the flouridated cities had a higher rate of cancer, both had the same rate of increase over the years. (15%)

Studies done on the toxicity of fluoride itself have been done as well. Two animal studies were conducted by the National Tooxicology Program of the National Institue of Environmental Health Sciences and The Proctor and Gamble Company. (7)(8) There was eight groups of animals each with its own sex and species. The animals were given 25, 75 and 175 ppm of fluoride respectively. The studies concluded that "Taken together the two animal studies fail to establish an association between fluoride and cancer."

Studies from the New Jersey Department of Health have now confirmed a 6.9 fold increase in bone cancer in young males

In April 2006, a preliminary study was published that observed an association between exposure to fluoride in drinking water and the incidence of osteosarcoma in young males. The author initially acknowledged that this study had limitations and further research is required to confirm or refute this observation. After reviewing the study:

"The principal investigator for the overall study cautions against over interpreting or generalizing the results of the Bassin analysis, stressing that preliminary analysis of a second set of cases does not appear to replicate the findings."(8)
"A number of studies regarding water fluoridation and osteosarcoma have been published in the past. At this time, the weight of the scientific evidence, as assessed by independent committees of experts, comprehensive systematic reviews, and review of the findings of individual studies does not support an association between water fluoridated at levels optimal for oral health and the risk for cancer."  -Center for Disease Control

Other conclusions regarding cancer risks have been the same:
“Many studies, in both humans and animals, have shown no association between fluoridated water and risk for cancer.”   -National Cancer Institute

"there has been nodetectable cancer risk to humans as evidenced by extensive human epidemiological data reported to date" -Public Health Service

"In 1993, the Subcommittee on Health Effects of Ingested Fluoride of the National Research Council, part of the National Academy of Sciences, conducted an extensive literature review concerning the association between fluoridated drinking water and increased cancer risk. The review included data from more than 50 human epidemiological studies and six animal studies. The Subcommittee concluded that none of the data demonstrated an association between fluoridated drinking water and cancer." (1b)


Fluoridated water causes osteoscheloris and other bone altering illnesses

This claim is true but misleading. In a survey of 170,000 people's xrays from Texas and Oklahoma, who had lived in communities whose water supply contained 4ppm-8ppm of fluoride, only 23 cases of osteoschelorsis had been found. Not one case of the more severe skeletal fluorosis. (2) Other studies have determined that toxicity may occur 10 years after exposure to HIGH levels. (over 5ppm) (3) N0te that this is much higher than the optimal safety guidelines. The reason that there are still communities today with more than 5ppm in their water supply is due mainly to the fact that they use natural water supplies (rivers, lakes). Another study done where community water supplies contained even higher amounts of fluorides (20 ppm) concluded that there was no evidence of advanced skeletal fluorosis. In the past 35 years, there has only been 5 documented cases of advanced bone disorders that may be linked to fluoridated water. (4)

Several European countries have banned water fluoridation
This is entirely false. Not one European country has banned water fluoridation. The United Kingdom uses water fluoridation extensively. One of the reasons this claim is so common is the fact that a lot of European countries have adopted alternatives to water fluoridation such as salt fluoridation. Salt fluoridation regulates fluoride intake in food, whereas we regulate it in our drinks. For example, in 2003, Basel, Switzerland voted to switch from water fluoridation to salt fluoridation because of technical and practical reasons. (10)  Even in countries that don't require salt or water fluoridation like Sweden and the Netherlands, they still approve of the World Health Organization's recommendations regarding fluoridation as a preventative health measure. They also support fluoride toothpastes, mouthwash, and other fluoride supplements. (11) Other reasons for a country's choice not to adopt water fluoridation come down to complex water system issues, (pipes and maintenance), practicality and politics. Water fluoridation is used in 60 different counties worldwide, and it's safety has been unanimously agreed upon everywhere.





Water Fluoridation is ineffective

The evidence is overwhelming that fluoridated water helps prevent tooth decay. Gran Rapids, Michigan, which was the first city to fluoridate was observed in a study showed children who consumed fluoridated water had 50-63% less dental decay than children examined during the original baseline survey completed in non fluoridated Michigan. Other studies which in some cases analyzed 113 studies from 23 countries came to the same conclusions. (12)(13)(14)(15)

Nazis put fluoride in the water supply at the concentration camps

This claim may just be an internet fabrication as most sites promoting either lack a source or tell you to read " The Crime and Punishment of I.G. Farben". But let's just accept it for now. It is claimed that the Nazi's used fluoridated water to "dumb down" everyone at the concentration camps. If this is true, how much fluoride did they use? Given that they did not abide to a then nonexistent EPA regulation of 0.7-1.2 ppm, and that they have indeed added extra fluoride to the water supply, this amount would have to be much higher than what was naturally occuring in the German and Austrian river and creeks. As explained before where natural water contains 20ppm. So how much fluoride does it take to make people docile or better yet affect their behavior in any way? Since we have no Nazi fluoride records, we can only speculate. A 1995 study done on rats who consumed up to 125 times the EPA limit showed behavioral changes and cognitive deficits but even this study was critisized for lacking proper identification of the control groups. For the sake of argument let's assume that the study was done correctly. The study showed that 125 ppm of fluoride was neurotoxic for rats, not humans. Humans would require much more because of the obvious size difference. The Nazi's would have had to add at least 200 ppm of fluoride to the water supply at the concentration camps which is 200X the amount in our water. Even if the nazi story were true it is a non sequitur.

Another problem with the Nazi water fluoridation claim is that the Nazi's themselves would have to get their water from somewhere else. Why would the contaminate the entire water supply with large amounts of fluoride when they could control the people there with guns and putting up barbed wire fences?( which we know they did. )

Scientific American agrees that fluoride is bad

I'm sure there are many other sites that took advantage of this article, but i will focus on how infowars misrepresented  a Scientific American article about fluoride entitled "Second thoughts about fluoride". Infowars had the following headline on their website: "Scientific Study Finds Fluoride Horror Stories Factual Industrial by-product consumed by millions of Americans lowers IQ, causes cancer" (17)

Let's see what the actual article concludes.
"About 200,000 Americans—and several million people in China, India, the Middle East, Africa and Southeast Asia—drink concentrations higher than the limit, but their excess fluoride comes from naturally occurring runoff from fluoride-...The report is, however, prompting some researchers to wonder whether even 1 mg/L is too much in drinking water, in light of the growing recognition that food, beverages and dental products are also major sources of fluoride, especially for young children." (18)

The US wide average is .79 ppm, but the EPA limit is set at around 4 ppm. One of the questions that is still open is if they should reduce the EPA  limit, but as the quoted passage stated, it was questionable if that even 1ppm may be too high considering the growing recognition that a lot of food and beverages now contain fluoride.

"Consuming foods and beverages with large amounts of fluoride can put a diet above this range. Below are typical trace levels of fluoride, measured in parts per million (ppm), found in foods and drinks tested at the University of Iowa College of Dentistry."

A couple examples include: raisins (2.34ppm), brewed black tea (3.73ppm) and white wine (2.02ppm).Since there is a lot more fluoride used in products today, future studies could show that there too fluoride, and necessary measures would instate safer regulations. But this is speculative. Yes it is possible but this article in no way claims that the fluoride does lower IQ, or that it causes cancer. The ADA, FDA, WHO and numerous other agencies still maintain that fluoridated water is very safe. The article also mentions studies done in China which have not been repeated anywhere else in the world, and the studies themselves did not display a high correlation. (see china studies section) Even if a new study finds 1ppm to be too high, this does not mean that we had been poisoned or dumbed down by the the whole time resulted from a big government conspiracy. One reason would be that there has been hardly any cases of fluorosis since the fluoridated water systems started. This would have been a warning that people were consuming too much fluoride.
"Historically, dental fluorosis was quite widespread in the USA. Originally the problem was termed “mottled enamel” or, local to Colorado Springs, as “Colorado brown strain”. In 1930, the link was made between mottled enamel
and high levels of fluoride in drinking-water supplies (2.0–13.7 mg l–1) and the term fluorosis was adopted...."

Driscoll et al. (1983) noted that more than 700 communities in the USA were thought to have water supplies that contained at least twice the recommended optimum level of fluoride (i.e. 2.4 mg l–1 and above). They found mean fluoride concentrations in Illinois between 1.06 and 4.07 mg l–1. In a study in Texas (Segreto et al., 1984), fluoride concentrations varied between 0.3 and 4.3 mg l–1. At the highest fluoride concentration only 5.2 per cent of children were considered to have normal teeth or questionable mottling." (19)


Chinese studies indicate that high levels of fluoride can lower IQ

This claim is partially true, but misleading. There have been about a dozen studies done in China that may show a potential link. But China's water supply was not very safe to begin with, as its contains high levels of fluoride.

"Drinking water with high levels of fluoride is widespread in China and has been seen in all provinces, municipalities and autonomous regions with the exception of Shanghai, and it has been estimated (Guifan, pers. com.) that there are over 1,200 counties and almost 150,000 villages affected by fluorosis (including coal pollution derived fluorosis)."
Dental fluorosis in China has been recognized for some time (Anderson, 1932)." (20)

China has also had high rates of fluorosis, a clear sign that their citzens are consuming too much fluoride.

"It has been estimated that over 26 million people in China suffer from dental fluorosis due to elevated fluoride in their drinking-water, with a further 16.5 million cases of dental fluorosis resulting from coal smoke pollution (Liang
et al., 1997)." (20)

China does not fluoridate its water (except "the people's republic of china", so they get their water from natural sources. It's also worth mentioning that the lower IQ link may be from fluoride gases coming from coal/clay pollution, or from arsenic which is also in the water supply. (21)(22)

"we saw arsenic levels in the water that represent more than fifty times the EPA-recommended limit for consumption of fish and shellfish.”  (Dartmouth biologists)

The best way to understand these studies' findings, is to track the journals down and read the conclusions they've reached. This is from a study done in 2007.

“Additionally, we recognize that children in our study groups attend school and therefore are exposed to different levels of As (arsenic)  while not at home. All the complications and limitations of our study design, however, would not lead to systematic errors that would challenge the main findings: that 10-year-old Chinese children’s IQ scores were lowered by 5–10 points when they were exposed to drinking water containing 150–200 µg/L As. However, we emphasize the need for more careful evaluation of the effects of fluoride on intelligence." (23)

“Children’s intelligence and growth can be affected by high concentrations of As (arsenic) or fluoride. The IQ scores of the children in the high-As group were the lowest among the four groups we investigated. It is more significant that high concentrations of As affect children’s intelligence. It indicates that arsenic exposure can affect children’s intelligence and growth.”

In conclusion, the claim that high levels of fluoride cause a decline in IQ is inconclusive. The Chinese water supply is very different then the US water supply and contains other toxic elements that correlate with the cognitive decline. This is likely considering the studies done on rats indicated that cognitive decline required up to 75 times the epa limit. When you look at the totality of the evidence on water fluoridation safety, a link between lowered IQ and fluoridated water becomes unlikely.

The US IQ average has dropped in the past 50 years

According to most IQ researchers, the national IQ has actually been rising since the 1930's. This increase has been observed all around the world, and not just with IQ tests but with episodic and semantic memory tests. (25) This observation has been called the "Flynn effect". Some explanations for the "Flynn effect" are improved nutrition and better education.

"Average scores on intelligence tests are rising substantially and consistently, all over the world. These gains have been going on for the better part of a century—essentially ever since tests were invented." (25)

In fact, according to the data, the average IQ in the 1930's was 80! Right now the national average is 98. So the claim that the IQ has dropped since the introduction of fluoridated water is complete bunk. But intelligence really can't be measured by IQ tests alone. There are many other factors influencing one's ability to communicate, perform physical tasks and remember information, which are all part of intelligence too.


Fluorosis rates have increased in the United States in the past 30 years
True. According to the Center for Disease Control:


"Prevalence of enamel fluorosis has increased in cohorts born since 1980. This increase should be evaluated in the context of total fluoride exposure." (26)

About 10% of the cases of fluorosis can be attributed to fluoridated water. (27) The other 90% most likely comes from children who swallow toothpaste either by accident or because they think it tastes like candy. (28) Also note that the fluorosis that occurs now are extremely mild, to a point where they are more of a cosmetic problem than a health problem. Only 1% of the population suffers from fluorosis that has been listed as severe or moderate. Most of these cases are children. Overall, fluorosis is not a big problem, and the best way to prevent it is to make sure your kids don't eat any toothpaste.


* For any other questions or concerns, I highly recommend the American Dentistry Association's fact sheet on fluoride released in 2005. (16)

Sources for history section
1.http://www.webmd.com/oral-health/tc/tooth-decay-topic-overview
2. http://www.ada.org/public/resources/history/timeline_19cent.asp
3.http://inventors.about.com/od/dstartinventions/a/dentistry_2.htm
4. See sources
5. http://www.cdc.gov/mmwr/preview/mmwrhtml/00056796.htm

1. Hodge HC, Smith FA. Biological properties of iorganic fluorides. In: Fluorine chemistry. Simons HH. ed. New York: Academic Press
1b.National Research Council. Carcinogenicity of flouride. In: Subcommittee on Health Effects of Ingested Fluoride, editor. Health Effects of Ingested Fluoride. Washington DC: National Academy Press, 1993.
2. Stevenson CA, Watson AR. Fluoride osteoschelrosis. American Journal of Roetgenology, Radium Therapy and Nuclear medicine 1957; 78 (1) 13-18
3. Institute of medicine, Food and nutrition board. Dietery reference intakes for calcium, phosphorus, magnesium, vitamin D, and fluoride. Report of the standing committee on the scientific evaluation of dietery reference intakes. Washington, D.C: National Academy Press; 1997
4. Hodge HC. The safety of fluoride tablets or drops. In: continuing evaluation of the use of fluorides. Johansen E, Tavaes DR, Olsen TO, eds. Boulder, Colorado: Westview Press; 1979: 253-75
5. US Department of Health and Human Services, Public Health Service. Review of fluoride: benefits and risks. Report of the Ad Hoc Subcommittee on Fluoride. Washington, D.C; February 1991
6. Clemmensen J. The alleged association between artificial fluoridation of water supplies and cancerL a review Bulletin of the World Helath Organization 1983: 61 (5): 871-83
7. Bucher JR, Hejtmancik MR, Toft JD 11, Persing RL, Eustis SL, haseman JK. Results and conclusions of the National Toxicology Program's rodent carcinogenicity studies with sodium fluoride. INT J Cancer 1991;48: 733-7
8. Maurer JK, Cheng MC, Boysen BG, Anderson RL. Two-year carcinogenicty study of sodium fluoride in rats. J Natle cancer Insti 1990; 82: 1118-26
9.http://www.cdc.gov/fluoridation/fact_sheets/osteosarcoma.htm
10.Bergmann KE, Bergmann RL. Salt fluoridation and general health. Adv Dent Res 1995; 9 (2): 138-43
11.Meyer J, Marthaler TM Burgi H. The change from water to salt as the main vehicle for community wide exposure in Basle, Switzerland. Community Dent Oral Epidemiol 2003; 31(6):401-2
12. Centers for Disease Control and Prevention. Recommendations for using Fluoride to Prevent and control Dental crisis in the United States MMWR 2001;50 (NORR1v)
13.Murray JJ. Efficacy of preventative agents for dental caries. Caries Res 1993; 27 (supp 17:28 (A review of studies conducted from 1976-1987.
14.Newburn E. Effectiveness of water fluoridation. J Public Health dent 1989; 49 (5):27989 (The analysis of the results of 113 studies in 23 countires)
15. Ripa LW. A half century of community water fluoridation in the United States. review and commentary. J Pubic Health Dent 1993, 53(1); 17014(The analysis of 50 years of studies)
16.http://www.ada.org/public/topics/fluoride/facts/fluoridation_facts.pdf
17. http://www.infowars.com/articles/science/fluoride_study_finds_horror_stories_factual.htm
18. Second Thoughts about Fluoride; January 2008; Scientific American Magazine; by Dan Fagin; 8 Page(s)
20.http://www.who.int/water_sanitation_health/publications/fluoride_drinking_water_full.pdf
21. http://www.scidev.net/en/news/fluoride-poisoning-in-china-due-to-clay-not-coal.html
22.http://www.physorg.com/news119117913.html
23.http://fluoridealert.org/scher/wang.s-2008.pdf
24.Rönnlund M, Nilsson LG. (2009). Flynn effects on sub-factors of episodic and semantic memory: parallel gains over time and the same set of determining factors. Neuropsychologia. 47(11):2174-80
25.http://www.americanscientist.org/issues/feature/rising-scores-on-intelligence-tests/1
26. http://www.cdc.gov/mmwr/preview/mmwrhtml/ss5403a1.htm
27. http://www.ada.org/public/topics/fluoride/facts/fluoridation_facts.pdf
28. http://www.ncbi.nlm.nih.gov/pubmed/20091645