How fluoride's dental benefits were discovered.

Unfortunately, the analytical chemistry technology of the era was unable to discern any differences between water samples from regions with or without brown stain. Despite this, McKay persisted with his theory that something in the water was causing brown stain. He convinced the people of Oakley, Idaho, a region also troubled by brown stain, to change from wells to mountain run-off water. In a few years the condition disappeared, providing evidence that his theory was sound. It wasn't until 1931 that Alcoa chemist H.V. Churchill, using the new method of spectrographic analysis, determined that water samples from brown stain areas had up to 14 ppm fluoride. The initial reaction was to ask whether the high fluoride ingestion caused other undesirable effects. Studies of people in the brown-stain regions could find no adverse health effects other than dental fluorosis (although it is known that high levels of fluoride can cause skeletal fluorosis as well).

It was eventually determined that lower levels of fluoride protected teeth from decay without objectionable fluorosis. Continued research eventually led to the public health practice of fluoridation.

Fluoride's most important derives from exposure from birth to age 6 when teeth are being formed. Fluoride becomes part of the structure of teeth, making them harder and more acid-resistant.

This is called the systemic effect of fluoride. Waterborne fluoride is most effective because this method maintains the most consistent serum levels over time. Fluoride supplements also provide systemic effects, but pills do not maintain as consistent serum levels, are more expensive, and are less likely to be used effectively because pill-taking requires repeated action and supervision.

After the teeth are formed, maintaining the serum levels helps supply fluoride needed for teeth and bones to remain healthy.

Benefits from brushing with fluoride toothpaste, rinsing with fluoride solutions, or fluoride applications at a dentist's office are called topical effects.

Fluoride: a super element.

Fluoride is a stable, dissociated, ionized form of fluorine, the 17th most common element, 13th most common element in the earth's crust (averaging 290 ppm in the 10-mile deep crust), and 12th most in the ocean water. Fluoride is most abundant in regions that have experienced volcanism in their geological pasts. Fluorine never occurs in nature in its elemental form because, as the most electronegative and reactive of all elements, it combines readily with other natural substances -- most often calcium. The phenomenal power of the fluoride ion is attested to by the very narrow range in which its effects are seen. At 0.3 ppm, waterborne fluoride does not protect against tooth decay, whereas at 1 ppm it can reduce tooth decay significantly without objectionable fluorosis. At 2 ppm, waterborne fluoride begins to produce fluorosis in susceptible individuals. Antifluoridationists who point out that fluoride can produce adverse effects deliberately fail to mention that the concentrations that produce adverse effects is higher than the concentration produced by properly maintained fluoridation systems.

The vast majority of dentists and dental organizations advocate water fluoridation. If dentistry operated according to business ethics, it would favor a system that required consumers to obtain fluoride's benefits through dental offices.

Fluoride mouth rinse and tablets

Prophylaxis and fluoride gel

Safety is the primary issue that must be addressed, and any procedure that involves the public water supply must be safe beyond doubt.(Public water may undergo as many as 25 different treatments to make it potable.) Fluoridation is the most thoroughly studied public health intervention of all. Not only was it well studied before 1945 when Grand Rapids, Michigan became America's first fluoridated city, but studies have continued since that time as fluoridated cities are continually monitored by public health scientists. Some wonder whether fifty years is long enough to discover any unanticipated adverse long-term effects of fluoride ingestion. The reality is that scientists are not limited by the 50 years that fluoridation has been in effect.

Evidence is also available from studies of people who have lived for generations in regions where the natrual water supply contains effective levels of fluoride. Further, since seawater contains from 0.8 to 1.4 ppm fluoride, sea creatures have thrived in water with levels comparable to fluoridation for aeons.

Distortion of facts and sensationalism peaked in 1978 when Congressional hearings were held on the charge that fluoridation was causing cancer . As a result of those hearings the National Toxicology Program (NTP) was asked to determine the toxicity and carcinogenicity of fluoride. The NTP was in the process of analyzing certain crude data when someone leaked the data, which led to an antifluoridation cover story in Newsweek

Health Effects of Ingested Fluoride (Executive Summary). (Committee on Toxicology, Nat'l Research Council) Nat'l Acad Press 1993.

Covers intake, metabolism, and disposition of fluoride; dental fluorosis; bone strength and the risk of bone fracture; effects on the renal, gastrointestinal, and immune systems; reproductive effects in animals; genotoxicity; and carcinogenicity in animals and humans; conclusions; and, recommendations for further research.

Part 1: covers the history of fluoridation; the history of the National Health Federation, the most important single antifluoridation organization at that time; and, exposes the scheme to create a cancer scare by John Yiamouyannis, PhD, who was hired by NHF to discredit fluoridation. Part 2 covers false claims used by antis: Fluoride is a poison, causes birth defects, is mutagenic, causes allergic reactions, causes cancer in animals, and contributes to heart disease. Describes the experience of Antigo, WI which learned the hard way not to listen to anti's propaganda -- it suspended and then reinstated fluoridation after child dental health declined.

Contains basic information on fluoride, history of discovery of fluoride's effects on teeth and bones, misinformation disseminated by antifluoridationists, safety issues, and current status at the time.

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Fluoride toothpastes are preventative agents that have met safety and effectiveness requirements.

FLUORIDE AND CANCER

An "exclusive" headline story in the Medical Tribune (12/28/89) proclaimed that a recently completed National Toxicology Program study has found a link between high doses of fluoride and bone cancer (osteosarcoma). Newsweek

flashed "The Fluoride Risk: Evidence of a Link to Cancer" on the cover of its February 5 issue. Both reports are based upon partial information that has been leaked to individuals in the EPA--a full report is not due until April. Without having the study to carefully analyze, objective critics are held at bay.

Background. The NTP study was an outcome of the 1977 Congressional hearings on prima anti-fluoridationist John Yiamouyannis' claim that cancer rates were significantly higher in fluoridated v. nonfluoridated cities. Follow-up studies by qualified epidemiologists in the USA and abroad did not confirm Yiamouyannis' claims. However, laboratory evidence that very high doses of fluorides had been associated with tumor growth and genetic damage was also presented. No investigator inferred that results with high fluoride doses were relevant to the 1-ppm levels used in fluoridation, but further study was called for regarding the carcinogenicity of fluoride.

Reports of Findings. Newsweek states that the study involved a two-year feeding of rats and mice with varying levels of fluoride. No animals drinking fluoride-free water or the lowest level (11-ppm) developed cancer. But, one of 50 male rats consuming 45-ppm water, and 4 of 80 male rats on 79-ppm water, developed osteosarcoma (no female rats developed bone cancer). Whether or not these results were statistically significant was not reported, but the greater number of cancers at the higher fluoride dose was said to possibly indicate a dose-response effect, which would support a possible cause-effect relationship.

No reason to panic. This is not the first time very high doses of fluoride have been linked to adverse reactions--even tumor growth. Fluoride is a potent trace element. The mere fact that adjusting the level found in water from .3-ppm to 1.0-ppm can result in dramatic improvement in dental caries is evidence of fluoride's biological power. Fluoride is not the only trace element to exhibit paradoxical effects. Selenium deficiencies have been associated with reduced cancer and excesses with excess cancer, and simply increasing calories in rodent diets will increase tumors. The theory that high doses fed to small numbers of rodents for a short period will yield valid data on the effect of small doses on large numbers of humans over the long term is highly questionable. Yet this is the reasoning when testing for carcinogenicity.

What should be done. Whether or not fluoride is linked to osteosarcoma in humans should not be hard to test.

Fluoride exposure of the roughly 2100 new cases annually, and fluoride bone levels in cases and controls should be easily measured.

In time JY's charges led to a U.S. Senate hearing. Legislators asked the National Toxicology Program (NTP) to test the cancer-causing potential of fluoride. An NTP study of the effects of high doses of fluoride on rats completed in 1991 produced "equivocal" results regarding osteosarcoma (bone cancer).

The New York Department of Health's Department of Occupational Health, and Yale University's Dept of Epidemiology and Public Health, conducted a case-control study in which 130 subjects diagnosed with osteosarcoma between 1978 and 1988 at age 24 or younger were matched with control subjects by gender and year of birth. Total fluoride exposure was based upon interviews wit h subjects and/or their parents. Researchers concluded that fluoride exposure does not increase the risk of osteosarcoma, and may have a protective effect in males. The protective effect may not be directly due to fluoride exposure but to other factors associated with good dental hygiene. B ecause 99% of ingested fluoride is deposited directly into bone, there is a biologic plausibility for a protective effect.

Californians can also expect to hear from John Lee, MD, a Mill Valley family practice physician. Lee authored "Optimal fluoridation" (Western J Med 1975;122:431-6). Lee assessed the fluoride intake of 10 children and found that some got enough to protect them from tooth decay without fluoridation. He argues that fluoridation is no longer needed because of fluoride from other sources including foods processed with fluoridated water. This issue has some validity, but the catch-22 is that discontinuing fluoridation would cut off the food processing source.

Water companies often oppose fluoridation because it means more work (installation, monitoring, supplying and maintenance) for them. The best thing that profluoridation forces have going for them is recent findings that fluoride appears to reduce osteoporosis as well as tooth decay. This means benefits to a broader spectrum of the population.

Early findings from the "Lifetime rat carcinogenicity study with sodium fluoride," commissioned by Procter & Gamble and performed at Hazelton Laboratories of Madison, Wisc., found no bone or oral tumors in about 700 rats tested on levels of fluoride that were double those of the National Toxicology Program that have been recently publicized as showing fluoride to be carcinogenic. Neither study has been finalized, and both sets of results should be considered preliminary. However, the above study should provide incentive for overzealous reporters to wait for the scientific analysis. The Hazelton Laboratories report appeared in the American Dental Association News, March 5, 1990.

New Study Finds No Fluoride-Cancer Link

Fluoride Will Not Appear in NTP Annual Cancer Report

The company estimates that it will take about 30 months to supplement the trace amounts of naturally occurring fluoride in the district's imported source waters from the Colorado River and Northern California to optimum levels. The California Dental Association Foundation, in cooperation with a statewide fluoridation task force, has offered to pay the $5 million cost of installing the equipment. The U.S. Centers for Disease Control and Prevention estimates that in 2000,.about 162 million people (65.8% of the U.S. population served by public water systems) received optimally fluoridated water.

John R. Butcher, PhD, Head of General Toxicology at the Experimental Toxicology Branch of the National Toxicology Program says that the results of the sodium fluoride studies that caused such a furor this Spring will not receive mention in the NTP Sixth Annual Report on Carcinogens because listing in that document typically requires a positive response in carcinogenicity studies with two species of animals. The results of the studies they conducted were that there was no evidence of cancer in male or female mice, or in female rats, and the evidence in male rats was equivocal. (6/6/90 Letter to John Small, National Institutes for Dental Research.)