
Water Fluoridation May Not Prevent Cavities, Scientific Review Shows - rl3
http://www.newsweek.com/fluoridation-may-not-prevent-cavities-huge-study-shows-348251
======
jessriedel
Just so everyone is clear: this review found that there is little evidence
that water fluoridation has any benefits. It does not dispute that fluoride in
toothpaste reduces tooth decay.

> Studies that attest to the effectiveness of fluoridation were generally done
> before the widespread usage of fluoride-containing dental products like
> rinses and toothpastes in the 1970s and later, according to the recent
> Cochrane study. So while it may have once made sense to add fluoride to
> water, it no longer appears to be necessary or useful, Thiessen says.

> It has also become clear in the last 15 years that fluoride primarily acts
> topically, according to the CDC. It reacts with the surface of the tooth
> enamel, making it more resistant to acids excreted by bacteria. Thus,
> there's no good reason to swallow fluoride and subject every tissue of your
> body to it, Thiessen says.

> Another 2009 review by the Cochrane group clearly shows that fluoride
> toothpaste prevents cavities.

~~~
mikeyouse
The theory I've encountered is that fluoridation previously had an impact on
cavity-prevention before people were actually brushing their teeth with
fluoridated toothpaste. Now that toothbrushing is much more common, the impact
has waned.

Late edit;

Here's a look at toothbrushing frequency in Europe by country from 1994 -
2010:

[http://i.imgur.com/VVBldAy.jpg](http://i.imgur.com/VVBldAy.jpg)

Just imagine how much improvement you'd see from if the chart started in the
1940's and 1950's when many cities began fluoridating their water supplies.
Not to mention that many early toothpastes were often ineffective at
preventing cavities by primarily relying on baking soda and peroxide.

(Full brushing frequency study:
[http://eurpub.oxfordjournals.org/content/25/suppl_2/20](http://eurpub.oxfordjournals.org/content/25/suppl_2/20)
)

~~~
gcb0
remember that non controlled measurements are worthless.

same time they started water fluoridation the population also started to pay
attention to brushing their teeth. or do you think the govt took the
initiative at any point in history?

------
JeremyNT
This article has such a bad headline.

The important thing to note here is that this review is looking for the
impacts of fluoridation _since the 1970s_. The evidence remains clear that
fluoridation is better than nothing at preventing cavities! The question at
hand is whether it's _still_ important now that we have widespread adoption of
fluoride toothpaste.

This Cochrane study concludes, as many Cochrane reviews do, that there's not
yet enough high quality evidence to answer this question.

The takeaway here shouldn't be the absurd headline that "fluoridation may not
prevent cavities," it should be "we should study how effective fluoridation is
now that we have added other successful interventions."

~~~
SuddsMcDuff
The headline introduces an element of doubt in something that was previously
reckoned to be conclusive. I'd say it's pretty effective.

------
evunveot
From what I've read, we've already identified the specific bacteria
responsible for tooth decay [1], but there seems to have no interest in
developing treatments based on that insight. Instead we're supposed to
essentially sterilize our mouths and remineralize our teeth (which is
something saliva does naturally) with topical fluoride twice a day.

My cat has never brushed her teeth, and they're fine, presumably because the
microbiome in her mouth is in a state where bacteria that secrete lactic acid
are crowded out by benign species. Granted, she doesn't eat many simple
sugars, but I _have_ had a vet recommend brushing her teeth twice a day as a
preventative measure, which blew my mind.

I hope I live to see the day when the extent of oral hygiene maintenance and
bad breath prevention is a toothpick and an occasional probiotic mouthwash or
something.

[1]
[https://en.wikipedia.org/wiki/Dental_caries#Bacteria](https://en.wikipedia.org/wiki/Dental_caries#Bacteria)

~~~
brianwawok
Have you seen a 50 year old cat? I bet their teeth would be completely rotten.

Okay so house cats don't live that long.. but look at longer living mammals
like horses. Their teeth are terrible at 20 years old.

I think the human teeth will do fine without brushing for 20-30 years, enough
to make babies. They aren't really designed for the 75 year life plan..

~~~
nulltype
I know tons of people under 30 who have a lot of cavities.

~~~
brianwawok
Sure but the can smash up food well enough to live.

------
tokenadult
As the article notes, this is all based on the Cochrane Collaborative
methodology of searching for prior published scientific literature, and is not
a conclusion based on a fresh study. The article also points out, "Another
2009 review[link] by the Cochrane group clearly shows that fluoride toothpaste
prevents cavities, serving as a useful counterpoint to fluoridation’s
uncertain benefits."

[link] [http://www.cochrane.org/CD002278/ORAL_fluoride-
toothpastes-f...](http://www.cochrane.org/CD002278/ORAL_fluoride-toothpastes-
for-preventing-dental-caries-in-children-and-adolescents)

"Tooth decay (dental caries) is painful, expensive to treat and can sometimes
lead to serious damage to teeth. Fluoride is a mineral that prevents tooth
decay. The review of trials found that children aged 5 to 16 years who used a
fluoridated toothpaste had fewer decayed, missing and filled permanent teeth
after three years (regardless of whether their drinking water was
fluoridated). Twice a day use increases the benefit."

~~~
jessriedel
A new Cochrane meta-analysis is much more likely to make me change my mind
about some empirical claim than a fresh study.

~~~
tokenadult
On the whole, the Cochrane Collaboration is a force for good, but its
methodology of reviewing previous published studies lets it miss important
issues of prior plausibility (that is, lack of plausibility) when reviewing
"alternative" treatments.

[https://www.sciencebasedmedicine.org/of-sbm-and-ebm-redux-
pa...](https://www.sciencebasedmedicine.org/of-sbm-and-ebm-redux-part-iv-
continued-more-cochrane-and-a-little-bayes/)

~~~
jessriedel
I don't think this has anything to do with Cochrane's methodology. This is
about choice of presentation.

They are very clear in the paper that they are reviewing a certain body of
studies, and that there are other plausible reasons ( _not_ backed up by RCTs)
to believe water fluoridation could have beneficial effects. The numbers they
quote summarize the evidential content of the RCTs. I don't need or want them
to bundle this all into one Bayesian percentage. This would be dominated by
their own priors which I do not necessary share nor are necessary shared by
anyone I discuss the study with. (Yet we can all agree on the frequentist
summary of the RCTs.)

------
lutorm
Having grown up in Sweden, being told that fluoride applied topically was
functional at reducing caries but that eating toothpaste or swallowing the
fluoride rinse that we got in elementary school was bad for you, I was
astonished to learn that some countries put it in their water.

Even in the U.S., toothpaste containers warn you not to swallow it and contact
a Poison Control Center if you accidentally do. And then they put it in tap
water? It just seems really inconsistent.

~~~
aggie
Just a guess but those cases are probably due to the fluoride concentration of
the rinse and toothpaste. Things that can be beneficial at small doses can be
harmful in larger doses.

------
giarc
Can we change the link to the actual Cochrane review which does provide a
plain language interpretation of the results?

[http://onlinelibrary.wiley.com/doi/10.1002/14651858.CD010856...](http://onlinelibrary.wiley.com/doi/10.1002/14651858.CD010856.pub2/abstract)

~~~
jmckib
Here's an anchor link directly to the plan language summary.
[http://onlinelibrary.wiley.com/doi/10.1002/14651858.CD010856...](http://onlinelibrary.wiley.com/doi/10.1002/14651858.CD010856.pub2/abstract#shortAbstract)

------
jrcii
I can no longer sit back and allow Communist infiltration, Communist
indoctrination, Communist subversion and the international Communist
conspiracy to sap and impurify all of our precious bodily fluids.

~~~
jjulius
Mandrake, have you ever seen a Commie drink a glass of water?

~~~
vbnmvbnmvbnm
Ice cream, Mandrake? _Children 's_ ice cream?

------
ChaoticGood
It is a great idea to revisit public policies that were put into place at the
same time Doctors were advertising Cigarettes as healthy. Water is a precious
resource and should be protected as such.

"Generally, in Germany fluoridation of drinking water is forbidden. The
relevant German law allows exceptions to the fluoridation ban on application.
The argumentation of the Federal Ministry of Health against a general
permission of fluoridation of drinking water is the problematic nature of
compuls[ory] medication." (Gerda Hankel-Khan, Embassy of Federal Republic of
Germany, September 16, 1999).[0]

Germany halted its water fluoridation in the 1970s and France never
started.[1]

[0] [http://www.slweb.org/50reasons.html](http://www.slweb.org/50reasons.html)
[1] [http://www.theguardian.com/world/2013/sep/17/water-
fluoridat...](http://www.theguardian.com/world/2013/sep/17/water-fluoridation)

~~~
_delirium
Generally Europe doesn't fluoridate its water, true, but the practical effect
is a bit more nuanced. For example, Germany has mostly moved its fluoridation
program from water to salt:
[http://www.ncbi.nlm.nih.gov/pubmed/16156167](http://www.ncbi.nlm.nih.gov/pubmed/16156167)

In Denmark the water isn't fluoridated, but its natural levels of fluoride are
only slightly lower than the levels that U.S. cities add (for example in the
Copenhagen water supply, fluoride is around 0.6 mg/L). So it's a bit pedantic
to claim that it isn't fluoridated. It's true that the utility company is not
adding _more_ fluoride to the water, but the end result is still that the
pipes are delivering tap water with fluoride in it.

------
colordrops
Harvard study finding fluoride in water does negatively impact childhood
development:

[http://www.hsph.harvard.edu/news/features/fluoride-
childrens...](http://www.hsph.harvard.edu/news/features/fluoride-childrens-
health-grandjean-choi/)

~~~
mikeyouse
It's important to note that this study was performed in China where they don't
intentionally fluoridate their water supply. There are many areas with natural
(or industrial waste..) levels of fluoride and many of these areas far exceed
the level recommended for use in the US.

The current target concentration in the US is 0.7mg/L and is routinely
monitored and lowered if the background level is too high where some of the
'hot spots' in China that saw childhood development issues had water
containing above 6mg/L and one area had a range from 118mg/kg to 1,361mg/kg
(thank you coal mining).

Another confounding factor is that many of the areas with high fluoride levels
also had high aluminum, mercury, and arsenic levels as well.

I'd like to see a study comparing IQs or development with actual usage levels
and without the heavy metal pollutants from industry.

Full HSPH study:

[http://ehp.niehs.nih.gov/wp-
content/uploads/2012/09/ehp.1104...](http://ehp.niehs.nih.gov/wp-
content/uploads/2012/09/ehp.1104912.pdf)

~~~
colordrops
What's your agenda in coming in and claiming the paper is irrelevant? It would
have been better to let people read the paper and come to their own
conclusions instead of draft off of your biased summary. If you actually read
the paper, you would see that some of the regions that reported neurotoxic
effects had levels that were lower than the legal limit in the US.
Furthermore, the paper claimed that other toxins were factored in to the
conclusion. See:

> Drinking water may contain other neurotoxicants, such as arsenic, but
> exclusion of studies including arsenic and iodine as co-exposures in a
> sensitivity analysis resulted in a lower estimate, although the difference
> was not significant.

But this story is already off the front page and you succeeded in burying my
post and defending fluoride for some strange reason, so you win.

------
cvwright
They don't fluoridate the water here in Portland, OR. Compared to other parts
of the country where I've lived, the difference in people's teeth is pretty
shocking. I haven't heard any alternative hypothesis that would explain this
difference better than the lack of fluoridation here.

As I understand the article, they're saying that they couldn't find rigorous
studies demonstrating the beneficial effects of fluoride. They don't claim
there's any evidence _against_ fluoride having beneficial effects, just that
the studies haven't been done.

~~~
stephengillie
There's too much inertia in favor of fluoride being beneficial for any serious
researcher to risk their credibility. Everyone "knows" fluoride makes teeth
stronger, like lettuce being healthy to eat, or global warming is human-
caused.

In fact, even discussing the possibility is too much for most people to
entertain. They think you're wasting their time with fantasy and falsehood,
like conspiracy theorists always do. Fluoride being bad for teeth is as
believable as airliners dropping chemtrails everywhere, or jet fuel not
"spheroiding" steel after hours of heating.

~~~
stephengillie
See? Even posting about the idea of researching it merits a downvote. The idea
that fluoride has no benefits is as popular as Apple and Microsoft merging.

------
cromulent
Correlation.

Everyone should get the right amount of fluoride. This is actually quite
difficult to measure and achieve.

WHO seem to have a good viewpoint:

"The effects of fluoride are best predicted by the dose (i.e. mg fluoride per
kg of body weight per day), the duration of exposure and other factors such as
age (e.g. dental fluorosis). However, most epidemiological studies concerning
the effects of fluoride on teeth and bone have correlated the effects with the
concentration of fluoride in the drinking-water (mg l–1 fluoride) consumed
rather than total fluoride exposure. ... Perhaps the best general advice that
can be given in relation to local conditions is that, at a minimum, the
fluoride level in local water supplies should be monitored and the population
examined for signs of excessive fluoride exposure (e.g. moderate and/or severe
dental fluorosis and crippling skeletal fluorosis). Where treatment to remove
fluoride is practised, chemicals used should be of a grade suitable for use in
drinking-water supply as outlined in the WHO Guidelines for Drinking-water
Quality."

[http://www.who.int/water_sanitation_health/publications/fluo...](http://www.who.int/water_sanitation_health/publications/fluoride_drinking_water_full.pdf?ua=1)

------
SQL2219
yea well, it reduces IQ, so we're keeping it.

[http://www.hsph.harvard.edu/news/features/fluoride-
childrens...](http://www.hsph.harvard.edu/news/features/fluoride-childrens-
health-grandjean-choi/)

------
ownedthx
Since there are US cities like Texarkana, AR that have not have fluoride in
the water ever, it seems they would be a decent way to harvest some data
quickly and get to the bottom of this.

Anecdotally, I know a dentist that would work 2 days a week there as a sort of
'import-a-dentist' program, and she thought teeth were, in general, in much
worse shape there than Little Rock, AR (3 hours away). Not enough to go on
obviously.

~~~
facetube
Portland, Oregon doesn't have any fluoride in its water supply either, for
what it's worth.

~~~
ownedthx
Seemingly a good list;
[http://fluoridealert.org/content/communities/](http://fluoridealert.org/content/communities/)

------
nixy
Methods to prevent tooth decay were investigated and documented in Sweden back
in the 30's and 40's. Studies were carried out at a mental hospital where
patients were force fed sugary sweets to provoke caries. I believe
fluoridation was one of the things found to help prevent caries.

[https://en.wikipedia.org/wiki/Vipeholm_experiments](https://en.wikipedia.org/wiki/Vipeholm_experiments)

------
gtrubetskoy
An educational video from Univ. of Nottingham, if you don't know how nasty
(and fun) Fluorine is:
[https://www.youtube.com/watch?v=vtWp45Eewtw](https://www.youtube.com/watch?v=vtWp45Eewtw)
(and they explain the tooth enamel theory towards the end as well).

------
jane_is_here
Yet another excellent reason to not get your scientific information from the
popular media.

------
BuckRogers
Wasn't this obvious the whole time? You don't need a study to show that
drinking fluoridated water doesn't help your teeth. Fluoride is applied
topically.

------
marze
My policy: if someone wants me to eat poison, even if in small doses, there
better be some really bulletproof evidence of benefit.

------
nsxwolf
Here comes all the kids with rotten teeth and measles.

------
ForEnglandJames
So it really was just for mind control... :3

------
fapjacks
Oh, so then that means that fluoride is actually for mind control. Gotcha.

~~~
fapjacks
I see the sarcasm was completely lost on at least four geniuses.

~~~
biot
Fortunately for the quality of this site, there were only a few people who
lacked the self-restraint needed to avoid pointing out such a painfully
obvious, reddit-esque joke.

~~~
fapjacks
>quality

I take it you're new here. HN has been "tech reddit" for at least a couple of
years now.

(This will probably whoosh miles overhead, too).

------
NoMoreNicksLeft
Did anyone expect it to do so?

Fluorine production was a proxy for uranium production if the only use for
fluorine was for uranium production. Couldn't have the Soviets knowing how
many atom bombs we were building, so we needed to use it for something else
too. Something so massive that it would make it impossible to calculate how
much was used for nukes. And so we put it in the water supply as an additive.

~~~
x5n1
According to the Fluorine Deception, they needed a way to get rid of the
effluent so they made it a health product rather than toxic waste. That book
however has been dismissed by most supporters of fluoridation as written by a
nutbar.

[http://www.amazon.com/The-Fluoride-Deception-Christopher-
Bry...](http://www.amazon.com/The-Fluoride-Deception-Christopher-
Bryson/dp/1583227008)

"Concerns over fluoridated drinking water have long been derided as the
obsession of McCarthyite cranks. But this muckraking j’accuse asserts that
fluoride is indeed a dire threat to public health, one foisted upon the nation
by a vast conspiracy—not of Communist agents, but of our very own military-
industrial complex. Investigative reporter Bryson revisits the decades-long
controversy, drawing on mountains of scientific studies, some unearthed from
secret archives of government and corporate laboratories, to question the
effects of fluoride and the motives of its leading advocates. The efficacy of
fluoridated drinking water in preventing tooth decay, he contends, is dubious.
Fluoride in its many forms may be one of the most toxic of industrial
pollutants, and Bryson cites scientific analyses linking fluoridated drinking
water to bone deformities, hyperactivity and a host of other complaints. The
post-war campaign to fluoridate drinking water, he claims, was less a public
health innovation than a public relations ploy sponsored by industrial users
of fluoride—including the government’s nuclear weapons program. Legendary spin
doctors like Edward Bernays exploited the tenuous link between dental hygiene
and fluoridation to create markets to stimulate fluoride production and to
prove the innocuousness of fluoride compounds, thereby heading off lawsuits by
factory workers and others poisoned by industrial fluoride pollution. Bryson
marshals an impressive amount of research to demonstrate fluoride’s
harmfulness, the ties between leading fluoride researchers and the
corporations who funded and benefited from their research, and what he says is
the duplicity with which fluoridation was sold to the people. The result is a
compelling challenge to the reigning dental orthodoxy, which should provoke
renewed scientific scrutiny and public debate."

~~~
niels_olson
> affluent

effluent

~~~
x5n1
thx. corrected.

