The study, published in PNAS, examined Wisconsin state testing records, archival information about when Wisconsin cities began to fluoridate their water, and data from the Wisconsin Longitudinal Study, which has followed a random sample of 10,317 high school seniors from 1957 through 2026. Key findings include:
- There is no evidence supporting a connection between community water fluoridation and children’s IQ.
- There is also no evidence supporting a connection between community water fluoridation and cognitive functioning at various points later in life.
- Findings confirm evidence published in previous research which also used a national sample, but considered school achievement test scores instead of actual IQ scores.
For your information if you think fluoridation of water is bad:
Fluoride in the water is the opposite of bad, it’s good for your teeth. It’s in toothpaste for a reason! There is no reasonable evidence that fluoride causes any major health problems, in fact, the fluoridation of water is dubbed as one of the largest public health accomplishments in a while. In addition, the fluoride added to water is miniscule, tiny, far far too low in concentration to be toxic. 0.7-1.2 mg / L is the range that most countries that implement water fluoridation add to their water supply. For reference, the WHO recommends 1.5 mg / L as the upper limit. Additionally, in many places, the groundwater has fluoride levels a bit higher than that.It also occurs in plenty of foods naturally too (fruits, seafood, spinach, etc.)
Some more information of fluoride:
https://my.clevelandclinic.org/health/treatments/11195-fluoride
https://www.cdc.gov/oral-health/prevention/about-fluoride.html
https://www.sciencedirect.com/science/article/abs/pii/S000291652334718X
In many countries, particularly in developing nations, fluoridation of water is too expensive (since you need the infrastructure for it), and fluoride toothpastes are preferred instead. But in industrialised countries, where infrastructure for managing the water supply already exists, fluoridation of water is more effective.
Ireland and England both implement the fluoridation of water. In particular, 73% of Ireland’s population drinks fluoridised water
https://ukhsa.blog.gov.uk/2016/04/13/water-fluoridation-what-it-is-and-how-it-helps-dental-health/ (UK) https://pmc.ncbi.nlm.nih.gov/articles/PMC4081215/ (Ireland)
Additionally, so does Canada:
https://www.canada.ca/en/services/health/publications/healthy-living/fluoride-factsheet.html https://www.canada.ca/en/public-health/services/publications/healthy-living/community-water-fluoridation-across-canada.html
Other solutions to provide fluoride have also been pursued, such as in toothpastes (already mentioned), iodized salts, and milk. They each have varying effectiveness depending on the country.
TLDR:
- Fluoride added to water is too low to pose any significant health problems
- There are no studies to suggest that the 0.5-1.5 mg / L range that the WHO promotes is dangerous
- It’s not just the U.S., fluoridisation of water is present in Ireland, England, and Canada
- For the countries that do not pursue adding it to water, fluoridation is done through toothpastes, iodized salts, and milk
- Different strategies of fluoridation are pursued because some are more effective than others for that given region (e.g. toothpastes are more viable than treatment of water in developing nations)
- Fluoride is already present in many natural sources (fruits, veg, groundwater, etc.) and is safe in the recommended low concentrations (need to reiterate this!)
Arguing with internet people took many hours away from my life, so now I will redirect any silly discussion to this comment instead.
@CookieOfFortune@lemmy.world @fallaciousBasis@lemmy.world @pelespirit@sh.itjust.works @MrFappy@lemmy.world
Here you go
Again. I’m arguing for the benefits of fluoridation…
Many prior studies link reduced teeth rot to mental wellness, cognitive function, less cardiac issues, lower risk of stroke, less inflammation, less depression, and on and on.
There’s cross species studies on this.
Feeding pigs sweets “taints the meat” and the hogs start acting weird, often violent, and antisocial.
And indeed, trans species obvious basic biology… Diabetes is real. Etc. Excessive sugar doesn’t just rot teeth, it rots the whole body, including the brain.
My college teacher would be devastated
If fluoride doesn’t affect the nervous system, then why is your average American the way they are? Checkmate librulz!
Dammit. Why have I been drinking all this water then?
Better teef
Yeah. Flouride consumption isn’t an issue, but fearing flouride despite the studies, that’s a red flag.
Fuck Utah
Damn it. I was gonna come in here and be like, “Ah, that’s what big fluoride wants you to think, sheeple!”
You know, like a crazy person.
But it turns out the actual crazy people who truly believe that stupid shit are already out in full force.
Obligatory
No one is mentioning that it calcifies the pineal gland which prevents natural secretion of DMT as well as the ability to use our minds to travel.
One of the highest quality shitposts I’ve ever seen. Bravo!
Yeah, it caused my third eye to totally crust up. To be fair I was barely using it anyway.
You appear to be referencing this study. You would need to drink 21.5L/day of fluorinated water (standard 0.7 mg/L of fluoride) for this to apply to you.
Oh, and you’d also need to be a duck.
So, drinking a lot of fluorinated water will turn me into a duck. Got it.
Would I still weigh as much as a woman, then? Asking for science reasons.
Quack
as well as the ability to use our minds to travel.
This comment has big “teleport to Waffle House” energy.
This comment section is so bonkers, I can’t tell if you’re being sarcastic or not.
Not at all. It’s why I switched to a zero water filter. Drinking water with fluoride messes with our ability to reach our full potential, and at a time when that’s the most possible thanks to knowledge of the most effective techniques to do so.
For you information, that “zero water” filter is not that great for your health. It removes all the minerals and other bits in the water, and water without those minerals is not as good for you. Ultrapure water can absorb some of the minerals in your body, which obviously isn’t a very good thing.
Also, fluoride in the water is the opposite of bad, it’s good for your teeth. It’s in toothpaste for a reason! There is no reasonable evidence that fluoride causes any major health problems, in fact, the fluoridation of water is dubbed as one of the largest public health accomplishments in a while. In addition, the fluoride added to water is miniscule, tiny, far far too low in concentration to be toxic. It also occurs in plenty of foods naturally too (fruits, seafood, spinach, etc.)
Some more information of fluoride:
https://my.clevelandclinic.org/health/treatments/11195-fluoride
https://www.cdc.gov/oral-health/prevention/about-fluoride.html
https://www.sciencedirect.com/science/article/abs/pii/S000291652334718X
Water filters are still important*, just get a regular one that focuses on removing the bad stuff (lead, arsenic, that sort) rather than removing EVERYTHING
*if your tap water is unsafe to drink
I’ve survived over half a century without a water filter? For half of that, I was on a well.
Water filters are good when they filter out something you know is in the water that shouldn’t be.
Proud Flint resident right here ^
They’re also good when they filter out something you don’t know is in the water but shouldn’t be. You ever get that well water tested? Did that test include PFAS?
I saw a test that found Zero filters increased microplastics 10x or something like that.
Also, they’re pretty useless when they filter out beneficial minerals but miss the thing you didn’t know about that’ll kill you.
That well water got tested on a regular basis. It didn’t include PFAS because nobody tested for PFAS back then.
However, most filters today don’t filter PFAS. A good reverse osmosis filter will, or distillation. Problem with distillation is that it filters out all the good stuff too, so then you have to fortify your water.
Got it, I edited my comment
Our ability to reach our full potential.
Now I know you are just memeing.
Unfortunately, I’ve long since reached my full potential.
I did that on school sports day when my trainers fell off mid-run.
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I’m going to post this again, because everyone needs to fucking understand that science is studying results and a process:
What about autoimmune diseases and inflammation? It looks like there might be a link, but they haven’t studied it enough.
Based on the body surface area of humans and animals, and considering the metabolism and absorption of fluoride in rats, according to calculations, the WHO’s safety threshold for fluoride intake from drinking water (1.5 mg/L) corresponds to a fluoride concentration of 10 mg/L in the drinking water of rats. After 1 week of acclimatization, the 150 rats were randomly assigned to 5 groups (n = 30) and provided with drinking water containing 0, 10, 25, 50, or 100 mg/L of fluoride. Although 50 and 100 mg/L are not equivalent to the doses humans are exposed to in natural environments, they are commonly used in animal models of fluorosis and have been widely demonstrated to be robust in rat models of fluorosis [35,36,37]. According to the exposure mode and time of fluoride, it can be divided into three modes: fluoride treatment for 12 weeks (12 w), fluoride treatment for 24 weeks (24 w), and fluoride treatment for 12 weeks and 12 weeks of improve water(12 w12 wi) (Table S1). Rats were euthanized with isoflurane anesthesia at the end of the breeding period.
“We gave rats 6.66 times more than humans are exposed to and bad stuff happened.”
That’s really not a good methodology.
I mean, its fine - but it just isn’t overly meaningful for how we make decisions as individuals. But to design a scenario where we would absolutely see an effect is valuable to see if we should invest more money into larger studies.
Or as the saying goes in biotech: “everything works in mice”.
copying my answer from a different comment relating to fluoride:
Fluoride in the water is the opposite of bad, it’s good for your teeth. It’s in toothpaste for a reason! There is no reasonable evidence that fluoride causes any major health problems, in fact, the fluoridation of water is dubbed as one of the largest public health accomplishments in a while. In addition, the fluoride added to water is miniscule, tiny, far far too low in concentration to be toxic. It also occurs in plenty of foods naturally too (fruits, seafood, spinach, etc.)
Some more information of fluoride:
https://my.clevelandclinic.org/health/treatments/11195-fluoride
https://www.cdc.gov/oral-health/prevention/about-fluoride.html
https://www.sciencedirect.com/science/article/abs/pii/S000291652334718X
Eh the first major study in fluoride, the Grand Rapids study would never hold up to today’s standards. It was not a blind study and cavity detection is subjective.
Also drinking water is a poor way to deliver fluoride. The mechanism of action requires physical contact with your teeth to work. Toothpaste and mouthwash would be a better option and reduce consumption. To my knowledge, there hasn’t been a modern large scale study conducted looking into different delivery methods. We do have some evidence comparing countries that don’t fluoridate but still have low cavity rates.
And while rare, fluoride allergies do exist.
It can also be difficult to dose.
the first major study in fluoride, the Grand Rapids study would never hold up to today’s standards. It was not a blind study and cavity detection is subjective.
There has been many more studies on fluoride, none of which have shown that that the low concentrations of fluoride added to drinking water has any negative health effect. Not just the one, always check multiple sources!
Also drinking water is a poor way to deliver fluoride
It depends on the area you’re dealing with. In some countries, it’s more cost effective to put fluoride in the water supply, while in others, fluoride toothpastes are more effective. In Germany, they put fluoride in iodized salt!
There has been many more studies on fluoride, none of which have shown that that the low concentrations of fluoride added to drinking water has any negative health effect.
Again, there have not been any randomized control trials testing the efficacy of fluoride in drinking water compared to other delivery methods.
It depends on the area you’re dealing with. In some countries, it’s more cost effective to put fluoride in the water supply, while in others, fluoride toothpastes are more effective. In Germany, they put fluoride in iodized salt!
Did you just not read my comment? The reason isn’t cost, it’s not that expensive to add fluoride.
The reason is we wouldn’t be adding anything to drinking water if there were better alternatives. If we started again with today’s standards, no scientist would recommend fluoridated drinking water.
The reason isn’t cost, it’s not that expensive to add fluoride.
In many countries, particularly in developing nations, fluoridation of water is too expensive (since you need the infrastructure for it), and fluoride toothpastes are preferred instead. But in industrialised countries, where infrastructure for managing the water supply already exists, fluoridation of water is more effective. Places where tap water is more readily available (like the U.S.,
much of Western Europe, Canada, Ireland, etc.) will also be more likely to adopt the fluoridation of water.The reason is we wouldn’t be adding anything to drinking water if there were better alternatives. If we started again with today’s standards, no scientist would recommend fluoridated drinking water.
Fluoridation of water still helps to prevent tooth decay, and in regions where it is cost-effective, it is a great benefit to public health! Of course, fluoride toothpastes are great, but it’s not the best solution for everywhere.
much of Western Europe, etc.) will also be more likely to adopt the fluoridation of water.
Citation needed.
Of course, fluoride toothpastes are great, but it’s not the best solution for everywhere.
Why not? Or more specifically, why is this insufficient in the US? Are there studies comparing the efficacies?
much of Western Europe
Correction added to my comment, it looks like that for most of Western Europe, fluoridation in water is not common. That was a mistake and I acknowledge that, and I have edited my comment to reflect that.
However, Ireland and England both implement the fluoridation of water. In particular, 73% of Ireland’s population drinks fluoridised water
https://ukhsa.blog.gov.uk/2016/04/13/water-fluoridation-what-it-is-and-how-it-helps-dental-health/ (UK) https://pmc.ncbi.nlm.nih.gov/articles/PMC4081215/ (Ireland)
Additionally, so does Canada:
https://www.canada.ca/en/services/health/publications/healthy-living/fluoride-factsheet.html https://www.canada.ca/en/public-health/services/publications/healthy-living/community-water-fluoridation-across-canada.html
Why not? Or more specifically, why is this insufficient in the US?
Well, for one, tap water is readily available in the U.S., making fluoride super accessible to a large portion of the population! Also, fluoride toothpastes exist in the U.S. too, why can’t we have both? Both are effective at preventing tooth decay, perhaps toothpaste moreso (and there are studies that show that, you can easily search for yourself I think), but both help to prevent cavities.
That doesn’t clearly communicate the levels of fluoride necessary to show such a response.
That’s the part where they need to study it more.
Or they could have just shared that information from the study.
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But shouldn’t it? That’s what is claimed. But I’m certain enough there’s a large enough populace that doesn’t drink tap water to confound results.
copying my answer about fluoride, again:
Fluoride in the water is the opposite of bad, it’s good for your teeth. It’s in toothpaste for a reason! There is no reasonable evidence that fluoride causes any major health problems, in fact, the fluoridation of water is dubbed as one of the largest public health accomplishments in a while. In addition, the fluoride added to water is miniscule, tiny, far far too low in concentration to be toxic. It also occurs in plenty of foods naturally too (fruits, seafood, spinach, etc.)
Some more information of fluoride:
https://my.clevelandclinic.org/health/treatments/11195-fluoride
https://www.cdc.gov/oral-health/prevention/about-fluoride.html
https://www.sciencedirect.com/science/article/abs/pii/S000291652334718X
According to Wikipedia (I know, not the most accurate source. I just needed a quick statistic) the U.S. has a fluoride level of 0.7 mg / L since 2015. Poking around for other countries, it looks like 0.7-1.2 mg / L is the range that most countries add to their water supply.
For reference, the WHO recommends 1.5 mg / L as the upper limit. Additionally, in many places, the groundwater has fluoride levels a bit higher than that.
Ok?
Seems about 20 people, including you, didn’t get it.
So here’s what I was thinking earlier:
If you feed a pig sweets. What happens?
Their teeth rot. Same for humans.
If an animals teeth are rotting, oh boy. Guess what? I mean science will greet you with many associations (I’m sure some are causal)… Including heart disease, cognitive impairments, chronic inflammation, infection, carries, abcesses, etc.
Long story short, you really don’t want to eat that animal. And I imagine you really don’t want to be that animal.
Really short: shit breath often leads to a shit head.
So… if fluoride is so great… Apparently. So why doesn’t this show up, if it’s so great?
I would expect a positive association, based on the hype. This says it found none.
So what’s the benefit then?
Bad oral hygiene is associated with IQ decline. So if fluoride is helping alleviate that, where’s that data?
So what’s the benefit then?
Protection against tooth decay? I’m not sure I understand your point. That is a pretty big health benefit, I think, not sure why you think it’s not a positive effect. There are plenty of studies as to how fluoride (in the water or as toothpaste) can protect against cavities.
I will reiterate my point that fluoride levels in water is too low to be dangerous, as the WHO recommends a maximum of 1.5 mg / L for fluoridation of water, while most countries that implement it use a concentration of 0.7-1.2 mg / L. Additionally, fluoride is also naturally present in many fruits, seafood, etc. as well as many groundwater sources that are perfectly safe to consume.
edit: I think I understand what you are talking about. Yes, fluoride does not increase nor decrease IQ levels. Its main job is to protect against tooth decay. But that is still a public health benefit, no?
I guess I’ll reiterate. Many studies from early studies, after fluoridation became more common versus before, have found numerous benefits. Across the globe…
I think this study is more absence of evidence rather than evidence of absence.
Like… Shit. Say a kid has a cavity do you think he’s going to be focusing on his homework or his tooth hurting?
Decreasing number of cavities in children != increasing IQ
IQ only measures the ability to solve problems and pattern-match. And I would assume IQ tests are taken after cavities are dealt with.
To give an example, it’s the same thing as if you tried to give an IQ test to someone who, in the past, has had a bacterial infection. Then, when the person is perfectly healthy, you give them an IQ test once, then some antibiotics, then another IQ test giving the same result as the first. You would not conclude that antibiotics are ineffective and should be banned!
Fluoride doesn’t impact your IQ.
Whatever you’re on … does.
That is all.
Other studies disagree with that conclusion.
I mean… I can take any IQ test against you and I can tell you what I’m going to get… 98th percentile. That’s 130-140. Not perfect. But certainly above average.
Will you even break a hundred?
☝️🤓
Huh? It’s there for cavity prevention.
Read any scientific literature?
Yes, regularly.
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Are you having a stroke?
I’ll accept the null answer.
🍞🔥
The usefulness of fluoride is pretty well established at this point. If you have new data, please share it.
This study disagrees with you.
No significant difference.
You might wanna double check those p-values.
The study suggests no change in IQ values, not no change when it comes to protecting your teeth. To copy an example from a previous comment:
IQ only measures the ability to solve problems and pattern-match. And I would assume IQ tests are taken after cavities are dealt with. It’s the same thing as if you tried to give an IQ test to someone who, in the past, has had a bacterial infection. Then, when the person is perfectly healthy, you give them an IQ test once, then some antibiotics, then another IQ test giving the same result as the first. You would not conclude that antibiotics are ineffective and should be banned!
Wtf?
frongt noted that the fluoride is beneficial (for preventing tooth decay), while you state that the study denies this. This is untrue, as it just shows that fluoride doesn’t affect IQ (which primarily focuses on measuring logical thinking). It does not look at how it protects against cavities, there are plenty of studies on that already!
It’s the same thing as if you tried to give an IQ test to someone who, in the past, has had a bacterial infection. Then, when the person is perfectly healthy, you give them an IQ test once, then some antibiotics, then another IQ test giving the same result as the first. You would not conclude that antibiotics are ineffective and should be banned!
Your argument would replace bacterial infection with cavities and antibiotics with fluoridised water. Like the example with antibiotics, it is not a reasonable conclusion to state that no change to IQ = fluoridation in water is ineffective.
