
The issue presents a clash between two progressive positions: the desire to improve the dental health of low-income children and the impulse to avoid putting anything unnecessary in the air, food or water.
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"All fluoridation methods, including water fluoridation, create low levels of fluoride ions in saliva and plaque fluid, thus exerting a topical or surface effect. A person living in an area with fluoridated water may experience rises of fluoride concentration in saliva to about 0.04 mg/L several times during a day.[3] Technically, this fluoride does not prevent cavities but rather controls the rate at which they develop.[43]
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I vote we ship all the anti-vaccine anti-flouride people to Tacoma and put a fence around them.
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For years health experts have been unable to agree on whether fluoride in the drinking water may be toxic to the developing human brain. Extremely high levels of fluoride are known to cause neurotoxicity in adults, and negative impacts on memory and learning have been reported in rodent studies, but little is known about the substance’s impact on children’s neurodevelopment. In a meta-analysis, researchers from Harvard School of Public Health (HSPH) and China Medical University in Shenyang for the first time combined 27 studies and found strong indications that fluoride may adversely affect cognitive development in children. Based on the findings, the authors say that this risk should not be ignored, and that more research on fluoride’s impact on the developing brain is warranted.
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“Fluoride seems to fit in with lead, mercury, and other poisons that cause chemical brain drain,” Grandjean says. “The effect of each toxicant may seem small, but the combined damage on a population scale can be serious, especially because the brain power of the next generation is crucial to all of us.”
“These results do not allow us to make any judgment regarding possible levels of risk at levels of exposure typical for water fluoridation in the U.S.,” the researchers said in an e-mail response to questions from The Eagle. “On the other hand, neither can it be concluded that no risk is present."
Researchers are intensifying their scrutiny of fluoride, which is added to most public water systems in the U.S. Some recent studies suggest that overconsumption of fluoride can raise the risks of disorders affecting teeth, bones, the brain and the thyroid gland.
A 2006 report by a committee of the National Research Council recommended that the federal government lower its current limit for fluoride in drinking water because of health risks to both children and adults.
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. The NRC committee did not formally address the question, but its analyses suggest that lower water fluoridation levels may pose risks, too. “What the committee found is that we’ve gone with the status quo regarding fluoride for many years—for too long, really—and now we need to take a fresh look,” Doull says. “In the scientific community, people tend to think this is settled. I mean, when the U.S. surgeon general comes out and says this is one of the 10 greatest achievements of the 20th century, that’s a hard hurdle to get over. But when we looked at the studies that have been done, we found that many of these questions are unsettled and we have much less information than we should, considering how long this [fluoridation] has been going on. I think that’s why fluoridation is still being challenged so many years after it began. In the face of ignorance, controversy is rampant.”
The reality is that anyone making any confident statement on fluoride speaks way beyond the evidence. In 1999 the Department of Health commissioned the centre for reviews and dissemination at York University to do a systematic review of fluoridation and its effects on dental health. Little new work has been done since. In the review, 3,200 research papers, mostly of very poor quality, were unearthed. The ones that met the minimum quality threshold suggested there was vaguely, possibly, around a 15% increase in the number of children without dental caries in areas with fluoridated water, but the studies generally couldn't exclude other explanations for the variance. Of course, the big idea with fluoride in water is that it can reduce social inequalities in dental health since everyone drinks it. But there isn't much evidence on that either.
So when the British Dental Association says there is "overwhelming evidence" that adding fluoride to water helps fight tooth decay, it is in danger of stepping into line with Ripper. And when Johnson says fluoridation is an effective, relatively easy way to help address health inequalities, he is really just pushing an old-fashioned line which says complex social problems can be addressed with £50m worth of atoms.
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“These results do not allow us to make any judgment regarding possible levels of risk at levels of exposure typical for water fluoridation in the U.S.,” the researchers said in an e-mail response to questions from The Eagle. “On the other hand, neither can it be concluded that no risk is present."
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Only articles that meet good scientific standards (e.g., acknowledge and build upon other work in the field, rely on logical reasoning and well-designed studies, back up claims with evidence, etc.) are accepted for publication.
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Even though many of the studies on children in China differed in many ways or were incomplete, the authors consider the data compilation and joint analysis an important first step in evaluating the potential risk. “For the first time we have been able to do a comprehensive meta-analysis that has the potential for helping us plan better studies. We want to make sure that cognitive development is considered as a possible target for fluoride toxicity,” Choi said.
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Now, though, scientific attitudes toward fluoridation may be starting to shift in the country where the practice began. After spending more than two years reviewing and debating hundreds of studies, a committee of the National Research Council (NRC) released a report in 2006 that gave a tinge of legitimacy to some longtime assertions made by antifluoridation campaigners. The report concluded that the Environmental Protection Agency’s current limit for fluoride in drinking water—four milligrams per liter (mg/L)—should be lowered because of health risks to both children and adults. In children, consistent exposure to fluoride at that level can discolor and disfigure emerging permanent teeth—a condition called dental fluorosis. In adults, the same fluoride level appears to increase the risk of bone fracture and, possibly, of moderate skeletal fluorosis, a painful stiffening of the joints. Most fluoridated water contains much less fluoride than the EPA limit, but the situation is worrisome because there is so much uncertainty over how much additional fluoride we ingest from food, beverages and dental products. What is more, the NRC panel noted that fluoride may also trigger more serious health problems, including bone cancer and damage to the brain and thyroid gland. Although these effects are still unproved, the panel argued that they deserve further study.
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What the 'York Review' on the fluoridation of drinking water really found
Originally released : 28 October 2003
A statement from the Centre for Reviews and Dissemination (CRD).
In 1999, the Department of Health commissioned CRD to conduct a systematic review into the efficacy and safety of the fluoridation of drinking water. The review specifically looked at the effects on dental caries/decay, social inequalities and any harmful effects. The review was published on the CRD Fluoridation Review website and in the BMJ in October 2000.
We are concerned about the continuing misinterpretations of the evidence and think it is important that decision makers are aware of what the review really found. As such, we urge interested parties to read the review conclusions in full.
We were unable to discover any reliable good-quality evidence in the fluoridation literature world-wide.
What evidence we found suggested that water fluoridation was likely to have a beneficial effect, but that the range could be anywhere from a substantial benefit to a slight disbenefit to children's teeth.
This beneficial effect comes at the expense of an increase in the prevalence of fluorosis (mottled teeth). The quality of this evidence was poor.
An association with water fluoride and other adverse effects such as cancer, bone fracture and Down's syndrome was not found. However, we felt that not enough was known because the quality of the evidence was poor.
The evidence about reducing inequalities in dental health was of poor quality, contradictory and unreliable.
Since the report was published in October 2000 there has been no other scientifically defensible review that would alter the findings of the York review. As emphasised in the report, only high-quality studies can fill in the gaps in knowledge about these and other aspects of fluoridation. Recourse to other evidence of a similar or lower level than that included in the York review, no matter how copious, cannot do this.
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What is more, the NRC panel noted that fluoride may also trigger more serious health problems, including bone cancer and damage to the brain and thyroid gland. Although these effects are still unproved, the panel argued that they deserve further study.
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