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Fluoridated water is literally all around us in naturally occurring springs and drinking water humans have used for thousands of years. Generally speaking, we h

Fluoridated water is literally all around us in naturally occurring springs and drinking water humans have used for thousands of years. Generally speaking, we have a very good idea of what the benefits are and what our general tolerance is for fluoridated water.

adrian_b 2y ago
That is true and that is why it is known that in the regions where the natural water has a high content in fluoride it affects negatively the bones of the humans who live there. The reasons why adding fluoride to drinking water is extremely stupid are that there exists no evidence whatsoever that the ingested fluoride can have any beneficial effect on teeth, there exists no known mechanism through which ingested fluoride can have any beneficial effect (the enamel of the teeth does not have blood vessels), but there is ample evidence that too much ingested fluoride is harmful. All the evidence about beneficial effects of fluoride is about the external contact between teeth and fluoride, when the fluoride ions substitute the hydroxide ions in enamel. This is a simple chemical reaction, it is not a biological reaction mediated by an enzyme. This beneficial effect is achieved best by the use of toothpaste or mouth washes with fluoride, which can provide much more fluoride than it would be safe to ingest. It is impossible to optimize the concentration of fluoride in drinking water for a maximum effect on teeth while not being harmful after ingestion, because the amount of water that is drunk daily is variable and unpredictable. Moreover, the fluoridated drinking water would have a much greater beneficial effect if one would keep the water in the mouth for some time before swallowing it, which nobody does, so most of the fluoride in the drinking water has no opportunity to provide any beneficial effect.
- UltraSane 2y ago
  "there exists no evidence whatsoever that the ingested fluoride can have any beneficial effect on teeth" That is simply wrong. When fluoride comes into contact with developing teeth, it incorporates into the enamel crystal structure, forming fluorapatite, which is more resistant to acid attacks from bacteria that cause cavities.
- fzeroracer 2y ago
  > exists no evidence whatsoever that the ingested fluoride can have any beneficial effect on teeth This is just objectively wrong. We've known for almost a hundred years now that ingested fluoride reduces dental problems. Literally the entire reason why fluoridation of water got started was because scientists noted that in regions with higher than average naturally occurring fluoride levels in water resulted in fewer caries.
  - adrian_b 2y ago
    Very false. That is not evidence that ingested fluoride reduces dental problems. When the water with fluoride is drunk, the fluoride ions come in contact with the teeth and a very small fraction of them succeed to substitute hydroxide ions in the enamel before the water is swallowed. After the water is swallowed the only way for fluoride to reach again the teeth is when a very small fraction of the ingested fluoride exits again the body into saliva. Both these actions, from the water while it is drunk and from saliva are extremely inefficient in comparison with the use of toothpaste with fluoride, because only a very small part of the fluoride introduced in the drinking water has the opportunity of interacting with the teeth. When fluoride is inside the body, it does not have any beneficial effect, but it can interfere with the growth of bone tissue and it may have other less understood harmful effects. The body can deal with fluoride intakes that are not excessive, mostly by eliminating it into urine, but the fact that we can tolerate fluoride in small quantities cannot be an argument for introducing it intentionally in our bodies.
    - woodruffw 2y ago
      There is very strong population-scale evidence that municipal fluoridation significantly reduces the incidence of caries in children, including in developed countries with strong conventions around dental health (brushing twice a day, flossing, etc.)[1][2]. (A lot of this research comes from comparing cities/communities in Canada, since Canada is among the few countries that have gone on-again, off-again with municipal fluoridation. This in turn makes the data really strong, since there are relatively few confounding factors when comparing dental outcomes between Canadian children, versus children spread across the world.) Of note: the research also indicates that, if the general public were to brush twice a day with fluoride toothpaste, then municipal fluoridation would probably have only a marginal effect on overall dental health outcomes. But there's no strong evidence that redirecting money away from municipal fluoridation towards dental health education would meaningfully move the needle on individual practices; to the contrary, there's strong evidence that a decent percentage of the population will never engage in baseline dental hygiene, and thus benefits disproportionately from municipal fluoridation. [1]: https://www.researchgate.net/publication/335773400_Affirmation_Fluoridated_Water_Reduces_Caries_in_Children https://www.researchgate.net/publication/335773400_Affirmati... [2]: https://onlinelibrary.wiley.com/doi/10.1111/cdoe.12685 https://onlinelibrary.wiley.com/doi/10.1111/cdoe.12685

adrian_b 2y ago

That is true and that is why it is known that in the regions where the natural water has a high content in fluoride it affects negatively the bones of the humans who live there. The reasons why adding fluoride to drinking water is extremely stupid are that there exists no evidence whatsoever that the ingested fluoride can have any beneficial effect on teeth, there exists no known mechanism through which ingested fluoride can have any beneficial effect (the enamel of the teeth does not have blood vessels), but there is ample evidence that too much ingested fluoride is harmful. All the evidence about beneficial effects of fluoride is about the external contact between teeth and fluoride, when the fluoride ions substitute the hydroxide ions in enamel. This is a simple chemical reaction, it is not a biological reaction mediated by an enzyme. This beneficial effect is achieved best by the use of toothpaste or mouth washes with fluoride, which can provide much more fluoride than it would be safe to ingest. It is impossible to optimize the concentration of fluoride in drinking water for a maximum effect on teeth while not being harmful after ingestion, because the amount of water that is drunk daily is variable and unpredictable. Moreover, the fluoridated drinking water would have a much greater beneficial effect if one would keep the water in the mouth for some time before swallowing it, which nobody does, so most of the fluoride in the drinking water has no opportunity to provide any beneficial effect.

UltraSane 2y ago
"there exists no evidence whatsoever that the ingested fluoride can have any beneficial effect on teeth" That is simply wrong. When fluoride comes into contact with developing teeth, it incorporates into the enamel crystal structure, forming fluorapatite, which is more resistant to acid attacks from bacteria that cause cavities.
fzeroracer 2y ago
> exists no evidence whatsoever that the ingested fluoride can have any beneficial effect on teeth This is just objectively wrong. We've known for almost a hundred years now that ingested fluoride reduces dental problems. Literally the entire reason why fluoridation of water got started was because scientists noted that in regions with higher than average naturally occurring fluoride levels in water resulted in fewer caries.
- adrian_b 2y ago
  Very false. That is not evidence that ingested fluoride reduces dental problems. When the water with fluoride is drunk, the fluoride ions come in contact with the teeth and a very small fraction of them succeed to substitute hydroxide ions in the enamel before the water is swallowed. After the water is swallowed the only way for fluoride to reach again the teeth is when a very small fraction of the ingested fluoride exits again the body into saliva. Both these actions, from the water while it is drunk and from saliva are extremely inefficient in comparison with the use of toothpaste with fluoride, because only a very small part of the fluoride introduced in the drinking water has the opportunity of interacting with the teeth. When fluoride is inside the body, it does not have any beneficial effect, but it can interfere with the growth of bone tissue and it may have other less understood harmful effects. The body can deal with fluoride intakes that are not excessive, mostly by eliminating it into urine, but the fact that we can tolerate fluoride in small quantities cannot be an argument for introducing it intentionally in our bodies.
  - woodruffw 2y ago
    There is very strong population-scale evidence that municipal fluoridation significantly reduces the incidence of caries in children, including in developed countries with strong conventions around dental health (brushing twice a day, flossing, etc.)[1][2]. (A lot of this research comes from comparing cities/communities in Canada, since Canada is among the few countries that have gone on-again, off-again with municipal fluoridation. This in turn makes the data really strong, since there are relatively few confounding factors when comparing dental outcomes between Canadian children, versus children spread across the world.) Of note: the research also indicates that, if the general public were to brush twice a day with fluoride toothpaste, then municipal fluoridation would probably have only a marginal effect on overall dental health outcomes. But there's no strong evidence that redirecting money away from municipal fluoridation towards dental health education would meaningfully move the needle on individual practices; to the contrary, there's strong evidence that a decent percentage of the population will never engage in baseline dental hygiene, and thus benefits disproportionately from municipal fluoridation. [1]: https://www.researchgate.net/publication/335773400_Affirmation_Fluoridated_Water_Reduces_Caries_in_Children https://www.researchgate.net/publication/335773400_Affirmati... [2]: https://onlinelibrary.wiley.com/doi/10.1111/cdoe.12685 https://onlinelibrary.wiley.com/doi/10.1111/cdoe.12685