[vallismortis]

Twenty years ago, I moved from Michigan (a state that uses fluoride) to Mississippi (a state that doesn't use fluoride). My dentist at the time told me that I was going to end up with tooth decay if I stayed down there for more than a few years. Sure enough, five years later I moved back to Michigan and ended up with a cavity in an unusual place. My (new) dentist in Michigan was completely unsurprised.

He said there are two problems with tooth decay in Mississippi:

1. They don't use fluoride in their water. 2. No decent dentist would ever work in Mississippi.

Fifteen years later, with no changes in dental hygiene in my entire life, and I've had no other problems with my teeth. Anecdotal evidence, maybe. But that is my experience.

[dhbanes]

I think the fact that fluoride is beneficial to your teeth is a settled fact. However, the issue being discussed is fluorides impact on brain health.

[adrian_b]

Fluoride is beneficial only when applied externally on the dental enamel, where it converts the hydroxyapatite synthesized by the human cells into fluorapatite, which is less soluble in the acids contained in food or excreted by bacteria.

On the other hand, ingested fluoride has no benefits, because it cannot reach the tooth enamel and when in too large quantities it has bad effects, e.g. it may cause bone damage.

Brushing the teeth or washing the mouth with something containing fluoride is very good, drinking water with fluoride is very stupid.

[XorNot]

Can you point to one single data point which has found any negative effect on human bones from excess consumption of fluoridated water at town water concentrations?

This should be easy since it's been done at enormous scale for decades so a huge quorum of people have spent their their lives drinking fluoridated water.

[adrian_b]

Skeletal fluorosis is well known to occur in regions where the natural drinking water has high fluoride content, e.g. in some regions from India and China.

You need search no further than Wikipedia.

I am not aware of any study about the incidence of fluorosis in places where the drinking water is fluoridated artificially, but it would be very difficult to do such studies, due to the lack of comprehensive past statistics, to the many confounding factors and because only few of the existing cases are detected. When someone heals a bone fracture they almost never do additional complex tests to determine if it was normal for the fracture to happen or its likelihood was increased by a condition like fluorosis.

In any case no such studies are really needed, because when you have an activity like ingesting fluoride, for which there is absolutely no evidence of benefits and no known mechanism by which it could provide benefits, but there is weak evidence that it might be harmful and there are known mechanisms by which it may be harmful, then there is no rational doubt whether that activity should be done or not.

[XorNot]

My dude people have died from ingesting too much water.

So you don't get to say "well obviously it's dangerous just cuz".

The dose makes the poison, and you are making a very specific claim about the dose.

[dosman33]

That is funny. However Ill postulate this: Why wouldn't someone go to where the most interesting work is to be found though? You don't become a military doctor if you don't find it interesting stitching up bullet holes. And vice versa, you don't become a military doctor if you're not interested in working on the same.

[arcticbull]

> Why wouldn't someone go to where the most interesting work is to be found though?

Well, Mississippi is ranked 34th in crime, 41st in education, 49th in healthcare, 49th in economy, 40th in fiscal stability, 47th in infrastructure and 36th in opportunity. Assuming a medical professional cares about anything other than "natural environment" in which they rank 16th, I suspect there's a long list of places they'd rather end up.

[1] https://www.usnews.com/news/best-states/rankings

[yCombLinks]

Because if you're educated, you generally don't want to move to Mississippi. I grew up there!

[VectorLock]

Thats a very HN opinion. Sometimes people pick careers for factors other than how interesting they are.

[jtbayly]

And sometimes they pick locations based on something other than "statistics" and "rankings."

[adrianN]

Maybe because people prefer earning money over interesting work?

[adgjlsfhk1]

because you're gay, or black, or not Christian, or don't want to be shot?

[pfannkuchen]

Or black? Are you aware that there are quite a lot of black people in Mississippi?

[heyoni]

What’s your point? Mississippi hasn’t exactly been receptive to the civil rights movement.

[ImPostingOnHN]

How did that come to be?

[manmal]

Not to refute your n=1, but reviews are a safer way of establishing whether something actually works. Eg here, from 2015:

> There is insufficient information to determine whether initiation of a water fluoridation programme results in a change in disparities in caries across socioeconomic status (SES) levels.

> No studies that aimed to determine the effectiveness of water fluoridation for preventing caries in adults met the review's inclusion criteria.

> Over 97% of the studies were at high risk of bias and there was substantial between‐study variation

From here: https://www.cochranelibrary.com/cdsr/doi/10.1002/14651858.CD...

TLDR: The existing research is low quality.

[rixary]

Is caries the Spanish word for it or is that actually an English word for cavity as well?

[manmal]

It's originally a Latin word and, as many other Latin words, is now a medical term in English.

[s0rce]

Genetics plays a huge roll. As does your daily dental hygiene routine. Based on you posting here means you probably have access to tooth brush, floss, tooth paste and somewhere to use them daily and effectively, this reduces the impact of water fluoridation variables.

[HWR_14]

For other people moving to Mississippi now, they make fluoride mouthwash that you can use daily to help counteract a lack of fluorinated water.

[dtech]

Is brushing twice a day with fluoridated toothpaste and floss or similar not a thing in the US? In Europe most countries don't fluoride tap water and there's not a massive tooth decay problem.

[rlt]

> No decent dentist would ever work in Mississippi.

This sounds like some elitist BS.

[throwaway290]

And since oral hygiene seems to be linked to eg. Alzheimers (https://www.medicalnewstoday.com/articles/264164) and flouride seems to be indispensable oral hygiene thing the issue is not so straightforward...

[newZWhoDis]

The link you mention is from the mouth bacteria/plaques and their leakage into the blood stream near the brain.

Fluoride is not an antibiotic, so there is no plausible mechanism for it’s known topical benefits to prevent bacterial growth that might lead to Alzheimer’s (itself a theory, but an interesting one)

[napier]

Municipal water fluoridation is problematic for a range of reasons but as a toothpaste and mouthwash it has merit and it actually does demonstrate direct bacterial growth arrest effects in addition to indirect substrate permissiveness inhibition via mineralisation.

“Fluoride acts to enhance membrane permeabilities to protons and compromises the functioning of F-ATPases in exporting protons, thereby inducing cytoplasmic acidification and acid inhibition of glycolytic enzymes.Basically, fluoride acts to reduce the acid tolerance of the bacteria. It is most effective at acid pH values. In the acidic conditions of cariogenic plaque, fluoride at levels as low as 0.1 mM can cause complete arrest of glycolysis by intact cells ofStreptococcus mutans.Overall, the anticaries actions of fluoride appear to be complex, involving effects both on bacteria and on mineral phases. The antibacterial actions of fluoride appear themselves to be complex but to be dominated by weak-acid effects.” https://cdnsciencepub.com/doi/10.1139/m95-133#:~:text=Basica....

[throwaway290]

Fluoride reduces disease by reducing acid that bacteria poop out. Diseased gums and decaying teeth is great for things to leak into blood.

[newZWhoDis]

Once again, this is akin to drinking sunscreen having a positive effect on lip skin cancer.

Yes, but… no.