Fluoride Action Network

Fluoride can harm teeth, bones

Source: Bangor Daily News | March 17th, 2007 | By Dr. Leo Leonidas
Location: United States, Maine

The residents of Mount Desert and Lincoln were wise to vote against water fluoridation. They just did a favor for their children and fellow residents.

Fluoride in our water system does not make sense considering the latest human and animal studies.

If all clinicians and policymakers read the latest report by the National Research Council, “Fluoride in Drinking Water,” released last March 2006, there should be no more questions that fluoride should not be mixed with our water supply.

Because of this report, the American Dental Association issued a warning last November telling parents they should not give fluorinated water to infants under 12 months old. This is the first time that the ADA acknowledged fluoride is not healthy for young children. If fluoride were safe for young children, the ADA would not reverse their 40-year-old policy of giving fluoride to infants.

The NRC, which advises our government on health policies, for the first time devoted a whole chapter to “Neurotoxocity and Neurobehavioral Effects.” They cited four studies from China that said children living in communities with high fluoride had lower IQs. In one of these studies, the children living in high fluoride communities had an average IQ of 92.2 compared to the low fluoride areas of 100.41. The “high” fluoride water content of this community is 2.47 milligrams per liter versus 0.36 mg per liter in the “low” fluoride area.

In the same chapter, the NRC stated: “In addition to a depletion of acethylcholinesterase, fluoride produced alteration in phospholipid metabolism and-or reductions in the biological energy available for normal brain function.” Acethylcholinesterase is an important chemical in the brain cells that is involved in the transfer of neural information. Changes in these particular brain cells receptors have been implicated in Alzheimer’s disease.

A report from the Chinese Journal of Pathology in 1992 by Dr. Du Li of Quiyang Medical College stated: “Fluorine passes through the placenta of chronic fluorosis mothers and accumulation within the fetus brain impacts the developing central nervous system and stunts neuron development.” He studied 15 therapeutically aborted fetuses between 5 to 8 months of gestation, with the mother having lived in a community with high fluoride and compared with ones from nonendemic areas whose brain cells were normal. The brain cell that is mainly affected in the fetuses from high fluoride area are the Purkinje cells. These are the same cells primarily affected in autism, as reported by Dr. Kern of the University of Texas Southwestern Medical Center.

For the adult population, the concern lies with the effect of drinking water on the bones. According to Dr. Hardy Limeback, who heads preventive dentistry at the University of Toronto, a lifetime of fluoride ingestion in areas where the water is fluoridated at about 1 part per million can change the quality of dentin and bone and may increase fracture rates for both.

He described a study that measured the fluoride content of bones in Toronto, where drinking water is fluoridated, and Montreal, where it is not. The study found that the average level of fluoride in bone is 1,033 ppm in Toronto and 643 ppm in Montreal. (About half of ingested fluoride is stored in bone.) The Toronto bone samples had altered architecture, which decreased their resistance to compression and higher density, but less mineral, which increased their brittleness, he said. “The study shows that fluoride lowers compressive strength and resilience, or toughness, of bone.”

Limeback also noted that moderate fluorosis, which involves yellow or brown mottling of teeth from excessive fluoride exposure, is occurring at rates as high as 30 percent in some fluoridated communities. Teeth with moderate fluorosis also have weaker dentin. “This may make adult teeth fracture more easily,” said Limeback.

The apparent benefit of fluoridation, reduced tooth decay, may simply be a function of delayed tooth eruption, Limeback said. It is well-known that permanent teeth take longer to erupt in children who drink fluoridated water, he observed. Studies comparing decay rates in fluoridated and nonfluoridated communities usually assess the mean number of decayed, missing and filled surfaces in permanent teeth of 12-year-old children. For example, a study conducted in 1990 found that 12-year-old children in fluoridated areas of the United States had a mean DMFS score of 2.46, while those in nonfluoridated areas had a score of 2.97. However, “if you control for delayed tooth eruption, the study shows no benefit,” Limeback said. “Take fluoride out of the water supply, and use the money spent for fluoridation to promote better public health.”

Considering the risk benefit ratio in the total health of our children, water fluoridation is not safe.


Dr. Leo Leonidas is a pediatrician in Bangor and an assistant clinical professor in pediatrics at Tufts University.