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I initially dismissed it as the same category of stupid as anti-vax beliefs, but it turns out that there are a decent amount of good studies showing a link betw

I initially dismissed it as the same category of stupid as anti-vax beliefs, but it turns out that there are a decent amount of good studies showing a link between fluoride in water and (slightly) lower IQ when pregnant mothers ingest the fluoride. Note that there is no significant effect after birth. The idea is to remove fluoride from water and advise pregnant women to use fluoride-free toothpaste. Everyone else can get enough fluoride from modern toothpastes, or regular dentist treatments. The logic is that fluoride in tap water made sense in the era before toothpaste had it, but now it is “overmedicating” a vulnerable fraction of the population.

culi 2y ago
The IQ link is very heavily lacking in evidence. In the actual research the main "risk" posed by flouridated water is actually fluorosis. This causes minerals in your enamel to be replaced with flouride which can cause them to be brittle in the long term. It's pretty uncommon but the thought is that now that flouride toothpaste are commonplace, the benefit of flouridated water is also way less. Which changes the calculus. A not insignificant number of researchers are advocating for the view that flouridating water just isn't worth it anymore and the (slight) risk of flourosis is more significant than the (slight) benefit of decreased dental caries.
- Jimmc414 2y ago
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  - crazygringo 2y ago
    What do you mean? There's literally tons of evidence. Do you think fluoride doesn't actually reduce cavities?
    - newZWhoDis 2y ago
      [flagged]
      - jiggawatts 2y ago
        That's just not true. Most of the studies simply compared areas with different amounts of natural fluoride in their local water supply, and applied some basic statistics comparing dental health. There have also been some A/B studies possible in areas that stopped or started using fluoride in their water. Multiple such studies have been done, globally, over many decades.
        Brybry 2y ago
        I think it depends on how strict your criteria and evidence requirements are. There are two Cochrane reviews that I saw on community water fluoridation: https://pubmed.ncbi.nlm.nih.gov/26092033/ https://pubmed.ncbi.nlm.nih.gov/26092033/ https://pubmed.ncbi.nlm.nih.gov/39362658/ https://pubmed.ncbi.nlm.nih.gov/39362658/ There is limited modern evidence (ie. in a world where everyone is brushing their teeth with fluoride toothpaste) of some reduction in tooth decay in children. There were no studies on adults that met the review criteria. Overall it seems like we just don't really know how much impact CWF currently has.
      - shlant 2y ago
        you're just lying https://www.cdc.gov/oral-health/data-research/facts-stats/fast-facts-community-water-fluoridation.html?utm_source=chatgpt.com https://www.cdc.gov/oral-health/data-research/facts-stats/fa...
    - amazingamazing 2y ago
      [flagged]
      - plaqueattack 2y ago
        You can’t be serious right now. Your teeth aren’t in your digestive tract.
        dcassett 2y ago
        > Your teeth aren’t in your digestive tract. However: Once ingested, the fluoride has a systemic affect on teeth before they erupt, incorporating into the matrix of developing teeth to increase the mineralization content and decrease the solubility of enamel. [1] [1] https://www.uspharmacist.com/article/current-fluoride-recommendations-for-the-pediatric-patient https://www.uspharmacist.com/article/current-fluoride-recomm...
      - deleted 2y ago
        [deleted]
      - dcrazy 2y ago
        Fluoridated toothpaste says not to swallow because it contains much higher concentrations of fluoride than drinking water. If you ingest too much toothpaste, it can cause your teeth to get blotchy: https://en.wikipedia.org/wiki/Dental_fluorosis https://en.wikipedia.org/wiki/Dental_fluorosis
        amazingamazing 2y ago
        Yup, but even for fluoride gels it says explicitly not to swallow. One because fluoride is toxic when concentrated, two because it needs to be on your teeth, not inside your belly.
      - freehorse 2y ago
        It increases fluoride content in the saliva
    - Jimmc414 2y ago
      [flagged]
      - mmsc 2y ago
        If your water was sourced """naturally""" from a spring with a high fluoride levels, I wonder if you'd call that an additive.
    - Spooky23 2y ago
      You can’t win. Freedom, IQ, precious bodily fluids. There’s no end to the nonsense. My city started fluoridating a few years ago. The crazy was off the chart, they’re still active. NYC has fluoridated for 60 years, you’d think someone would have figured out that the entire city is dumber.
      - like_any_other 2y ago
        Bodily autonomy is "nonsense"?
        scheeseman486 2y ago
        How do you feel about the fossil fuel industry, because they're responsible for far more carcinogens entering your body than Big Flouride.
        grues-dinner 2y ago
        Not just regular toxic chemicals, either, through the is plenty of that. Quite a bit of radiation too. And companies that adulterate, misrepresent and obfuscate what they put in food as well. No-one is putting corn syrup or brominated vegetable oil in food with any intention other than money money money. In fact, if I were an evil subgenius and really actively wanted to damage the IQs of the nation for some nefarious purpose, and it has to be substance-based, I'd avoid things with annoying oversight like public drinking water and vaccines and focus on food and pollution as a vector. If challenged, I just say "why do you hate my freedom to make a profit and provide jobs". Sure, the FDA and EPA exist, but even then you can get away with far, far more in those areas. Food wise, HFCS, BVO, etc, pollution wise, almost everything to with plastics or polymers, oil, coal, gas the list goes on and on.
        TheBicPen 2y ago
        Do you think bodily autonomy is absolute? Your comments seem to imply that bodily autonomy is the only relevant thing to consider when discussing patient care. The world doesn't work that way. Believe it or not, a doctor won't amputate a limb when you show up with a runny nose even if you insist that that's the procedure you want. Search up the 4 principles of biomedical ethics if you want to learn more about the factors that influence doctors' ethical decisions. Or do you mean that your opinion should trump that of any doctor or expert in any field when the issue pertains to your person? If that's the case, I wonder why you choose to participate in society at all, given that you're uncomfortable with the idea that other people might know more than you.
    - oaktrout 2y ago
      Fluorinated water minimally reduces cavities: https://www.cochrane.org/news/water-fluoridation-less-effective-now-past https://www.cochrane.org/news/water-fluoridation-less-effect... It was probably much more effective 50 years ago when fluoride was not in everyone's toothpaste.
  - afthonos 2y ago
    There isn’t any! GP doesn’t have that authority! Well done! On the other hand, the society you live in probably has some sort of document establishing who does have the authority, and how it devolves to the actual policy-makers. Google “$YOUR_LOCATION government” and you’ll have some good starting points. If you’re lucky, you might even get to participate in the process; “$YOUR_LOCATION elections” will give you good pointers in that case.
  - loktarogar 2y ago
    The people of Flint, MI were (and some still are!) forced to drink bottled water for years when their water was contaminated with lead. When you drink from publicly supplied water, you accept risks that can be much worse than fluoride in your water. If you want to avoid that, you need to procure your own drinking water.
  - cratermoon 2y ago
    7mg/L? Where the heck did you get that figure? The correct value is a tenth of that: 0.7 milligrams per Liter (mg/L) The limit is 2mg/L, and that's only found in places with naturally occurring high levels of flouride.
  - don_neufeld 2y ago
    You can solve your “problem” for a very small price: it costs under $0.50 per day to distill your own drinking water per person. So for $15/mo, “problem” solved. Are you doing that?
    - syspec 2y ago
      How does one go about doing that? For that price? I'd love to give it a go for my family
  - Sparkle-san 2y ago
    It's not your water, it's municipal water you purchase with the fluoride in it.
- userbinator 2y ago
  Which changes the calculus Was that intentional? (https://en.wiktionary.org/wiki/dental_calculus https://en.wiktionary.org/wiki/dental_calculus for those who didn't get the reference.)
  - kazinator 2y ago
    The canonical form is "I see what you did there".
- deleted 2y ago
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- kjkjadksj 2y ago
  Fluorosis is very common afaik. My dentist told me I have it: slightly whiter patches on my teeth. Then he showed me his own fluorosis. It actually is stronger than the old enamel.
- naasking 2y ago
  > The IQ link is very heavily lacking in evidence. Not really: https://jamanetwork.com/journals/jamapediatrics/fullarticle/2828425 https://jamanetwork.com/journals/jamapediatrics/fullarticle/...
  - shlant 2y ago
    your study has been heavily criticized where you already posted it: https://news.ycombinator.com/item?id=43523900 https://news.ycombinator.com/item?id=43523900 I can only assume once you see those very valid criticisms, you will update your references
    - naasking 2y ago
      Does the study not literally refute the claim that fluoride's negative impact on IQ is lacking in evidence, contrary to the original claim? What exactly do you think needs to be updated?
      - shlant 2y ago
        the original refutation was "fluoride in the drinking water concentrations is proven safe and it doesn't affect brains". Your study does not show that IQ is effected at concentrations that are being added to water supplies. Just because X can result from Y levels of some substance does't mean X results from Y-n concentrations.
        naasking 2y ago
        > the original refutation was "fluoride in the drinking water concentrations is proven safe and it doesn't affect brains". No, this is the original claim: > but it turns out that there are a decent amount of good studies showing a link between fluoride in water and (slightly) lower IQ when pregnant mothers ingest the fluoride. Then the parent replied that this IQ link is lacking evidence, which it's not, per the meta-analysis I cited.
        2y ago
- hedora 2y ago
  Children are the main group that benefits from fluoride in water because the fluoride helps strengthen teeth as they form. Lack of fluoride increases childhood cavities, leading to decreased academic performance. This was a real problem in the San Jose school district until recently. They started fluoridation of water in the last ten years, and were the biggest US city that didn’t fluoridate. The evidence of the above is clear according to SJ dentists I have talked to.
- somenameforme 2y ago
  The National Toxicology Program recently completed a fairly substantial meta study and concluded that "for every 1 mg/L increase in urinary fluoride, there is a decrease of 1.63 IQ points in children.". [1] This is also relevant to OP since it's not just pregnant women at risk from excessive fluoridation but also children. For now it seems that adults are, somewhat oddly, unaffected. [1] - https://ntp.niehs.nih.gov/whatwestudy/assessments/noncancer/completed/fluoride https://ntp.niehs.nih.gov/whatwestudy/assessments/noncancer/...
  - Aloisius 2y ago
    In bold from your source: > It is important to note that there were insufficient data to determine if the low fluoride level of 0.7 mg/L currently recommended for U.S. community water supplies has a negative effect on children’s IQ.
    - somenameforme 2y ago
      Yeah, note the measurement is in urine. So there are two separate issues. Determining whether fluoride is damaging to IQ, and then whether the levels in water can drive this. The former is way easier to evaluate than the latter. The reason comes from that study's intro pargraphs: --- "Since 1945, the use of fluoride has been a successful public health initiative for reducing dental cavities and improving general oral health of adults and children. There is a concern, however, that some pregnant women and children may be getting more fluoride than they need because they now get fluoride from many sources including treated public water, water-added foods and beverages, teas, toothpaste, floss, and mouthwash, and the combined total intake of fluoride may exceed safe amounts." --- So the issue is trying to isolate the exact amount and source of fluoride people are getting. And that probably has no answer because it's going to vary dependent on how much fluoridated water somebody drinks, the rest of their diet, their other dental hygiene composition, and more. So levels that would be safe for one percent of the population, will be dangerous for another percent of it.
  - efirman 2y ago
    Here is a concise detailed analysis of the concerns with the metaanalysis provided by the NTP: https://theunbiasedscipod.substack.com/p/the-well-runs-deep-examining-the https://theunbiasedscipod.substack.com/p/the-well-runs-deep-... The NTP report is flawed and likely biased.
Speedy218 2y ago
> but now it is “overmedicating” a vulnerable fraction of the population. Makes sense, but the intention also is that many people do not brush their teeth, or at least do not brush them as often as they should, and so fluoride is added to drinking water to compensate so people's teeth don't start to fall out at an alarming rate.
- apothegm 2y ago
  Sadly, an alarming percentage of Americans don't drink water. I’ve spoken to way too many people who think water tastes wrong because it’s not sweet enough.
  - singpolyma3 2y ago
    I've heard this and it doesn't fit in my brain. They never drink water? Ever?
    - TimTheTinker 2y ago
      Something like 10% of SNAP benefits go towards purchases of soda pop and other sugary drinks made by PepsiCo/etc.
      - kacesensitive 2y ago
        It’s heartbreaking, but not surprising. When you’re dealing with limited resources, constant stress, and often living in areas where healthy options are harder to access or more expensive, sugary drinks can feel like an affordable comfort. Instead of judging SNAP recipients, we should be looking at the systems that make soda more accessible than clean, appealing , and fresh food.
        milesrout 2y ago
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deleted 2y ago
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mountainriver 2y ago
Agree, my biggest issue is often where they source the fluoride and whether they test it. We found out in my (liberal) hometown that they were actually sourcing some derivative which has no human studies. Given that everyone gets enough in toothpaste I just don’t see the reason to keep doing it, too much can go wrong. It’s kind of a strange mass medication that I’m not sure the government needs to be involved in.
- someperson 2y ago
  What was the derivative?
deleted 2y ago
[deleted]
thayne 2y ago
> Everyone else can get enough fluoride from modern toothpastes, or regular dentist treatments. The advantage of putting it in water is that it ensures all children get it, not just the children whose parents can and do make sure they brush their teeth and go to the dentist.
- syspec 2y ago
  So everyone else's kids have to have a lower IQ because of that? Bad parents are gonna be bad parents.
jaredklewis 2y ago
I think that link is only there when the fluoride levels are extremely high. See https://parentdata.org/fluoride-drinking-water/ https://parentdata.org/fluoride-drinking-water/ for a good overview of the data
LeoPanthera 2y ago
Whether this is true or not, it's absolutely not why they banned it. They banned it as part of the culture war. That's 100% of the reason. "The libs" want it, so it must be banned.
robbiep 2y ago
The levels of fluoridation in order to cause difference in IQ as I understand it, from the Chinese studies, suggest that basically the effect if true occurs at around 2x+ the concentration found in supplemented water supplies. My understanding also is that if you’re a dentist wanting to get rich, move somewhere that has unfluoridated water.
- bigmadshoe 2y ago
  2x is honestly pretty small. I would expect the amount required to drop IQ to be larger by an order of magnitude or more to conclude that fluoridating water is totally safe.
- cortic 2y ago
  So if your training and double your water intake your basically lowering you IQ? (according to the Chinese studies) I wonder the method this uses.. has anyone looked at dementia rates in high fluoride areas.. Particularly in people with high water intake? There is also a host of things we use water for from cooking to preserving, distilling and cooling.. i wonder if any of these things could concentrate the fluoride. Also since fluoride has a lower boiling point any studies tracked what breathing in fluoride gas over long periods cause?
- raincole 2y ago
  2x is basically no safe margin for something like water. Of course you can question the quality of the study, but if it's actually 2x, fluoride in tap water should be treated like lead pipes.
windexh8er 2y ago
> The idea is to remove fluoride from water and advise pregnant women to use fluoride-free toothpaste. What most people don't understand here are the levels of fluoride being ingested. You can very easily remove all fluoride from your water with a relatively cheap RO system. But the recommendation to use "fluoride-free toothpaste" is just plain misinformation. The reason is that you don't eat toothpaste. And even when adults ingest small amounts of toothpaste, again, the amount of fluoride is basically beyond negligible. Fluoride can both be applied to teeth as a varnish and/or consumed in drinking water. Using a flouride-free toothpaste can oftentimes do more damage than good because of SLS in those alternatives and because those alternatives often have abrasives that do far more harm than good. It's amazing people will recommend a product that may likely be worse because they have no domain expertise. So, yes, people should talk to their Dentist about these things and ask questions of them vs the Internet. Really the downside to removing fluoride from city water is that low income families will be worse off with respect to dental related issues compared to more well off families that spend time instilling dental hygiene and preventative care for their kids. As you mentioned most people who have decent oral hygiene get enough flouride. Where we live we have well water. Fluoride in the water isn't a concern, and if it was in our drinking water it generally wouldn't be consumed because of the water filtration anyway. Source: spouse is a DDS.
- navigate8310 2y ago
  My anecdotal experience says that using fluride-free biomine toothpaste makes my tooth highly sensitive than using a good ol' Colgate. Now, I use it only twice or thrice per month randomly.
piuantiderp 2y ago
[flagged]
unsupp0rted 2y ago
> I initially dismissed it as the same category of stupid as anti-vax beliefs Dismissing things out of hand like this is a category of stupid in itself. Look at the current research, listen to people who devoted their careers to studying this, make up your own mind. If you're on HN, then you're qualified enough to at least figure out who the genuine experts are and read what they recommend. Putting any science-based debate into a "category" to dismiss is turning yourself into one of the stupid people.
- edanm 2y ago
  This is bad advice that no one could possibly follow. > Look at the current research, listen to people who devoted their careers to studying this, make up your own mind. Do you honestly do this with every single belief you have? Even every single controversial belief? Have you looked, yourself, into whether the world is flat? Whether the 9/11 conspiracy theories are true? Whether crop circles were created by aliens? These are all absurd conspiracy theories, but I assume most people don't know the "up to date" research on any of them, or what people who have "devote their careers" to research them say. And those are incredibly common and well known to be false theories. You have to take some things on faith to at least some degree - though to be clear, by "on faith" I mean "on faith of people you trust", which should really start with professional scientists etc. Also, it's totally fine to just say "I have no actual idea" about most things, and just go with what your current understanding of the status-quo position is.
  - unsupp0rted 2y ago
    > Even every single controversial belief? Yes. > Have you looked, yourself, into whether the world is flat? Whether the 9/11 conspiracy theories are true? Whether crop circles were created by aliens? Yes.

culi 2y ago

The IQ link is very heavily lacking in evidence. In the actual research the main "risk" posed by flouridated water is actually fluorosis. This causes minerals in your enamel to be replaced with flouride which can cause them to be brittle in the long term. It's pretty uncommon but the thought is that now that flouride toothpaste are commonplace, the benefit of flouridated water is also way less. Which changes the calculus. A not insignificant number of researchers are advocating for the view that flouridating water just isn't worth it anymore and the (slight) risk of flourosis is more significant than the (slight) benefit of decreased dental caries.

Jimmc414 2y ago
[flagged]
- crazygringo 2y ago
  What do you mean? There's literally tons of evidence. Do you think fluoride doesn't actually reduce cavities?
  - newZWhoDis 2y ago
    [flagged]
    - jiggawatts 2y ago
      That's just not true. Most of the studies simply compared areas with different amounts of natural fluoride in their local water supply, and applied some basic statistics comparing dental health. There have also been some A/B studies possible in areas that stopped or started using fluoride in their water. Multiple such studies have been done, globally, over many decades.
      - Brybry 2y ago
        I think it depends on how strict your criteria and evidence requirements are. There are two Cochrane reviews that I saw on community water fluoridation: https://pubmed.ncbi.nlm.nih.gov/26092033/ https://pubmed.ncbi.nlm.nih.gov/26092033/ https://pubmed.ncbi.nlm.nih.gov/39362658/ https://pubmed.ncbi.nlm.nih.gov/39362658/ There is limited modern evidence (ie. in a world where everyone is brushing their teeth with fluoride toothpaste) of some reduction in tooth decay in children. There were no studies on adults that met the review criteria. Overall it seems like we just don't really know how much impact CWF currently has.
    - shlant 2y ago
      you're just lying https://www.cdc.gov/oral-health/data-research/facts-stats/fast-facts-community-water-fluoridation.html?utm_source=chatgpt.com https://www.cdc.gov/oral-health/data-research/facts-stats/fa...
  - amazingamazing 2y ago
    [flagged]
    - plaqueattack 2y ago
      You can’t be serious right now. Your teeth aren’t in your digestive tract.
      - dcassett 2y ago
        > Your teeth aren’t in your digestive tract. However: Once ingested, the fluoride has a systemic affect on teeth before they erupt, incorporating into the matrix of developing teeth to increase the mineralization content and decrease the solubility of enamel. [1] [1] https://www.uspharmacist.com/article/current-fluoride-recommendations-for-the-pediatric-patient https://www.uspharmacist.com/article/current-fluoride-recomm...
    - deleted 2y ago
      [deleted]
    - dcrazy 2y ago
      Fluoridated toothpaste says not to swallow because it contains much higher concentrations of fluoride than drinking water. If you ingest too much toothpaste, it can cause your teeth to get blotchy: https://en.wikipedia.org/wiki/Dental_fluorosis https://en.wikipedia.org/wiki/Dental_fluorosis
      - amazingamazing 2y ago
        Yup, but even for fluoride gels it says explicitly not to swallow. One because fluoride is toxic when concentrated, two because it needs to be on your teeth, not inside your belly.
    - freehorse 2y ago
      It increases fluoride content in the saliva
  - Jimmc414 2y ago
    [flagged]
    - mmsc 2y ago
      If your water was sourced """naturally""" from a spring with a high fluoride levels, I wonder if you'd call that an additive.
  - Spooky23 2y ago
    You can’t win. Freedom, IQ, precious bodily fluids. There’s no end to the nonsense. My city started fluoridating a few years ago. The crazy was off the chart, they’re still active. NYC has fluoridated for 60 years, you’d think someone would have figured out that the entire city is dumber.
    - like_any_other 2y ago
      Bodily autonomy is "nonsense"?
      - scheeseman486 2y ago
        How do you feel about the fossil fuel industry, because they're responsible for far more carcinogens entering your body than Big Flouride.
        grues-dinner 2y ago
        Not just regular toxic chemicals, either, through the is plenty of that. Quite a bit of radiation too. And companies that adulterate, misrepresent and obfuscate what they put in food as well. No-one is putting corn syrup or brominated vegetable oil in food with any intention other than money money money. In fact, if I were an evil subgenius and really actively wanted to damage the IQs of the nation for some nefarious purpose, and it has to be substance-based, I'd avoid things with annoying oversight like public drinking water and vaccines and focus on food and pollution as a vector. If challenged, I just say "why do you hate my freedom to make a profit and provide jobs". Sure, the FDA and EPA exist, but even then you can get away with far, far more in those areas. Food wise, HFCS, BVO, etc, pollution wise, almost everything to with plastics or polymers, oil, coal, gas the list goes on and on.
      - TheBicPen 2y ago
        Do you think bodily autonomy is absolute? Your comments seem to imply that bodily autonomy is the only relevant thing to consider when discussing patient care. The world doesn't work that way. Believe it or not, a doctor won't amputate a limb when you show up with a runny nose even if you insist that that's the procedure you want. Search up the 4 principles of biomedical ethics if you want to learn more about the factors that influence doctors' ethical decisions. Or do you mean that your opinion should trump that of any doctor or expert in any field when the issue pertains to your person? If that's the case, I wonder why you choose to participate in society at all, given that you're uncomfortable with the idea that other people might know more than you.
  - oaktrout 2y ago
    Fluorinated water minimally reduces cavities: https://www.cochrane.org/news/water-fluoridation-less-effective-now-past https://www.cochrane.org/news/water-fluoridation-less-effect... It was probably much more effective 50 years ago when fluoride was not in everyone's toothpaste.
- afthonos 2y ago
  There isn’t any! GP doesn’t have that authority! Well done! On the other hand, the society you live in probably has some sort of document establishing who does have the authority, and how it devolves to the actual policy-makers. Google “$YOUR_LOCATION government” and you’ll have some good starting points. If you’re lucky, you might even get to participate in the process; “$YOUR_LOCATION elections” will give you good pointers in that case.
- loktarogar 2y ago
  The people of Flint, MI were (and some still are!) forced to drink bottled water for years when their water was contaminated with lead. When you drink from publicly supplied water, you accept risks that can be much worse than fluoride in your water. If you want to avoid that, you need to procure your own drinking water.
- cratermoon 2y ago
  7mg/L? Where the heck did you get that figure? The correct value is a tenth of that: 0.7 milligrams per Liter (mg/L) The limit is 2mg/L, and that's only found in places with naturally occurring high levels of flouride.
- don_neufeld 2y ago
  You can solve your “problem” for a very small price: it costs under $0.50 per day to distill your own drinking water per person. So for $15/mo, “problem” solved. Are you doing that?
  - syspec 2y ago
    How does one go about doing that? For that price? I'd love to give it a go for my family
- Sparkle-san 2y ago
  It's not your water, it's municipal water you purchase with the fluoride in it.
userbinator 2y ago
Which changes the calculus Was that intentional? (https://en.wiktionary.org/wiki/dental_calculus https://en.wiktionary.org/wiki/dental_calculus for those who didn't get the reference.)
- kazinator 2y ago
  The canonical form is "I see what you did there".
deleted 2y ago
[deleted]
kjkjadksj 2y ago
Fluorosis is very common afaik. My dentist told me I have it: slightly whiter patches on my teeth. Then he showed me his own fluorosis. It actually is stronger than the old enamel.
naasking 2y ago
> The IQ link is very heavily lacking in evidence. Not really: https://jamanetwork.com/journals/jamapediatrics/fullarticle/2828425 https://jamanetwork.com/journals/jamapediatrics/fullarticle/...
- shlant 2y ago
  your study has been heavily criticized where you already posted it: https://news.ycombinator.com/item?id=43523900 https://news.ycombinator.com/item?id=43523900 I can only assume once you see those very valid criticisms, you will update your references
  - naasking 2y ago
    Does the study not literally refute the claim that fluoride's negative impact on IQ is lacking in evidence, contrary to the original claim? What exactly do you think needs to be updated?
    - shlant 2y ago
      the original refutation was "fluoride in the drinking water concentrations is proven safe and it doesn't affect brains". Your study does not show that IQ is effected at concentrations that are being added to water supplies. Just because X can result from Y levels of some substance does't mean X results from Y-n concentrations.
      - naasking 2y ago
        > the original refutation was "fluoride in the drinking water concentrations is proven safe and it doesn't affect brains". No, this is the original claim: > but it turns out that there are a decent amount of good studies showing a link between fluoride in water and (slightly) lower IQ when pregnant mothers ingest the fluoride. Then the parent replied that this IQ link is lacking evidence, which it's not, per the meta-analysis I cited.
        2y ago
hedora 2y ago
Children are the main group that benefits from fluoride in water because the fluoride helps strengthen teeth as they form. Lack of fluoride increases childhood cavities, leading to decreased academic performance. This was a real problem in the San Jose school district until recently. They started fluoridation of water in the last ten years, and were the biggest US city that didn’t fluoridate. The evidence of the above is clear according to SJ dentists I have talked to.
somenameforme 2y ago
The National Toxicology Program recently completed a fairly substantial meta study and concluded that "for every 1 mg/L increase in urinary fluoride, there is a decrease of 1.63 IQ points in children.". [1] This is also relevant to OP since it's not just pregnant women at risk from excessive fluoridation but also children. For now it seems that adults are, somewhat oddly, unaffected. [1] - https://ntp.niehs.nih.gov/whatwestudy/assessments/noncancer/completed/fluoride https://ntp.niehs.nih.gov/whatwestudy/assessments/noncancer/...
- Aloisius 2y ago
  In bold from your source: > It is important to note that there were insufficient data to determine if the low fluoride level of 0.7 mg/L currently recommended for U.S. community water supplies has a negative effect on children’s IQ.
  - somenameforme 2y ago
    Yeah, note the measurement is in urine. So there are two separate issues. Determining whether fluoride is damaging to IQ, and then whether the levels in water can drive this. The former is way easier to evaluate than the latter. The reason comes from that study's intro pargraphs: --- "Since 1945, the use of fluoride has been a successful public health initiative for reducing dental cavities and improving general oral health of adults and children. There is a concern, however, that some pregnant women and children may be getting more fluoride than they need because they now get fluoride from many sources including treated public water, water-added foods and beverages, teas, toothpaste, floss, and mouthwash, and the combined total intake of fluoride may exceed safe amounts." --- So the issue is trying to isolate the exact amount and source of fluoride people are getting. And that probably has no answer because it's going to vary dependent on how much fluoridated water somebody drinks, the rest of their diet, their other dental hygiene composition, and more. So levels that would be safe for one percent of the population, will be dangerous for another percent of it.
- efirman 2y ago
  Here is a concise detailed analysis of the concerns with the metaanalysis provided by the NTP: https://theunbiasedscipod.substack.com/p/the-well-runs-deep-examining-the https://theunbiasedscipod.substack.com/p/the-well-runs-deep-... The NTP report is flawed and likely biased.

Speedy218 2y ago

> but now it is “overmedicating” a vulnerable fraction of the population. Makes sense, but the intention also is that many people do not brush their teeth, or at least do not brush them as often as they should, and so fluoride is added to drinking water to compensate so people's teeth don't start to fall out at an alarming rate.

apothegm 2y ago
Sadly, an alarming percentage of Americans don't drink water. I’ve spoken to way too many people who think water tastes wrong because it’s not sweet enough.
- singpolyma3 2y ago
  I've heard this and it doesn't fit in my brain. They never drink water? Ever?
  - TimTheTinker 2y ago
    Something like 10% of SNAP benefits go towards purchases of soda pop and other sugary drinks made by PepsiCo/etc.
    - kacesensitive 2y ago
      It’s heartbreaking, but not surprising. When you’re dealing with limited resources, constant stress, and often living in areas where healthy options are harder to access or more expensive, sugary drinks can feel like an affordable comfort. Instead of judging SNAP recipients, we should be looking at the systems that make soda more accessible than clean, appealing , and fresh food.
      - milesrout 2y ago
        [flagged]

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mountainriver 2y ago

Agree, my biggest issue is often where they source the fluoride and whether they test it. We found out in my (liberal) hometown that they were actually sourcing some derivative which has no human studies. Given that everyone gets enough in toothpaste I just don’t see the reason to keep doing it, too much can go wrong. It’s kind of a strange mass medication that I’m not sure the government needs to be involved in.

someperson 2y ago
What was the derivative?

deleted 2y ago

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thayne 2y ago

> Everyone else can get enough fluoride from modern toothpastes, or regular dentist treatments. The advantage of putting it in water is that it ensures all children get it, not just the children whose parents can and do make sure they brush their teeth and go to the dentist.

syspec 2y ago
So everyone else's kids have to have a lower IQ because of that? Bad parents are gonna be bad parents.

jaredklewis 2y ago

I think that link is only there when the fluoride levels are extremely high. See https://parentdata.org/fluoride-drinking-water/ https://parentdata.org/fluoride-drinking-water/ for a good overview of the data

LeoPanthera 2y ago

Whether this is true or not, it's absolutely not why they banned it. They banned it as part of the culture war. That's 100% of the reason. "The libs" want it, so it must be banned.

robbiep 2y ago

The levels of fluoridation in order to cause difference in IQ as I understand it, from the Chinese studies, suggest that basically the effect if true occurs at around 2x+ the concentration found in supplemented water supplies. My understanding also is that if you’re a dentist wanting to get rich, move somewhere that has unfluoridated water.

bigmadshoe 2y ago
2x is honestly pretty small. I would expect the amount required to drop IQ to be larger by an order of magnitude or more to conclude that fluoridating water is totally safe.
cortic 2y ago
So if your training and double your water intake your basically lowering you IQ? (according to the Chinese studies) I wonder the method this uses.. has anyone looked at dementia rates in high fluoride areas.. Particularly in people with high water intake? There is also a host of things we use water for from cooking to preserving, distilling and cooling.. i wonder if any of these things could concentrate the fluoride. Also since fluoride has a lower boiling point any studies tracked what breathing in fluoride gas over long periods cause?
raincole 2y ago
2x is basically no safe margin for something like water. Of course you can question the quality of the study, but if it's actually 2x, fluoride in tap water should be treated like lead pipes.

windexh8er 2y ago

> The idea is to remove fluoride from water and advise pregnant women to use fluoride-free toothpaste. What most people don't understand here are the levels of fluoride being ingested. You can very easily remove all fluoride from your water with a relatively cheap RO system. But the recommendation to use "fluoride-free toothpaste" is just plain misinformation. The reason is that you don't eat toothpaste. And even when adults ingest small amounts of toothpaste, again, the amount of fluoride is basically beyond negligible. Fluoride can both be applied to teeth as a varnish and/or consumed in drinking water. Using a flouride-free toothpaste can oftentimes do more damage than good because of SLS in those alternatives and because those alternatives often have abrasives that do far more harm than good. It's amazing people will recommend a product that may likely be worse because they have no domain expertise. So, yes, people should talk to their Dentist about these things and ask questions of them vs the Internet. Really the downside to removing fluoride from city water is that low income families will be worse off with respect to dental related issues compared to more well off families that spend time instilling dental hygiene and preventative care for their kids. As you mentioned most people who have decent oral hygiene get enough flouride. Where we live we have well water. Fluoride in the water isn't a concern, and if it was in our drinking water it generally wouldn't be consumed because of the water filtration anyway. Source: spouse is a DDS.

navigate8310 2y ago
My anecdotal experience says that using fluride-free biomine toothpaste makes my tooth highly sensitive than using a good ol' Colgate. Now, I use it only twice or thrice per month randomly.

piuantiderp 2y ago

[flagged]

unsupp0rted 2y ago

> I initially dismissed it as the same category of stupid as anti-vax beliefs Dismissing things out of hand like this is a category of stupid in itself. Look at the current research, listen to people who devoted their careers to studying this, make up your own mind. If you're on HN, then you're qualified enough to at least figure out who the genuine experts are and read what they recommend. Putting any science-based debate into a "category" to dismiss is turning yourself into one of the stupid people.

edanm 2y ago
This is bad advice that no one could possibly follow. > Look at the current research, listen to people who devoted their careers to studying this, make up your own mind. Do you honestly do this with every single belief you have? Even every single controversial belief? Have you looked, yourself, into whether the world is flat? Whether the 9/11 conspiracy theories are true? Whether crop circles were created by aliens? These are all absurd conspiracy theories, but I assume most people don't know the "up to date" research on any of them, or what people who have "devote their careers" to research them say. And those are incredibly common and well known to be false theories. You have to take some things on faith to at least some degree - though to be clear, by "on faith" I mean "on faith of people you trust", which should really start with professional scientists etc. Also, it's totally fine to just say "I have no actual idea" about most things, and just go with what your current understanding of the status-quo position is.
- unsupp0rted 2y ago
  > Even every single controversial belief? Yes. > Have you looked, yourself, into whether the world is flat? Whether the 9/11 conspiracy theories are true? Whether crop circles were created by aliens? Yes.