Was that intentional? (https://en.wiktionary.org/wiki/dental_calculus for those who didn't get the reference.)

Where is the evidence that you have the authority to add 7mg/L of fluoride to my drinking water when I request the option? I get that it helps with cavities but me personally want the option to brush my teeth and drink basic water without additives.

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.

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.

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.

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.

No. When decisions I take could affect others, that can, in a limited way, justify overriding bodily autonomy. E.g. preventing someone with an infectious disease from spreading it by quarantining them. Or when they can't make their own decisions, e.g. if they're children, suffering dementia, or are unconscious and time is critical.

> Believe it or not, a doctor won't amputate a limb

I struggle to understand how this is a reasonable, much less charitable, interpretation of my words. Bodily autonomy does not include commanding others. But people can refuse care, even when it is medically sound. Except in very limited circumstances, doctors may not force procedures or medicine on unwilling patients.

> 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.

One does not at all follow from the other. Experts in the field will tell me excessive sweets are bad for me (and I believe them) - should they get to put a block my credit card so it cannot be used to buy unhealthy snacks, only healthy food?

I have humored your post, now please explain to me: How does believing people have a right to refuse medical treatment imply I am uncomfortable with others being more knowledgeable?

Maybe that’s why they haven’t?

But being serious if it’s relatively low and the negative effects only occur during pregnancy it’s not that easy to measure it.

Obviously there is no conclusive evidence (even if the studies from China seem somewhat credible) but IMHO even if the likelihood of this being true is e.g. only 5-10%, risk of a population wide loss of 1-2 IQ points seems like a massively too high price to pay just to slightly reduce cavity rates.

Also dismissing all credible (albeit weak) scientific evidence out of hand just because crazy people hold similar beliefs is a about as stupid as what they are doing..

The Flynn Effect was the observation that real IQ scores were increasing over time. But sometime around 1990 this seems to have stopped in pretty much the entire developed world, including the US. I'm not implying that this is solely due to fluoridation, though it's certainly a plausible contributing factor. But as for your snark about 'someone would have figured out people are getting dumber' - well, they have, and we don't know why.

[1] (pop media coverage of study) - https://www.popularmechanics.com/science/a43469569/american-...

[1] (study - no paywall!) - https://www.sciencedirect.com/science/article/pii/S016028962...

And lower IQ scores don't necessarily say much about pure intelligence directly, a worsening education system could also contribute and that's not exactly far fetched. And your linked source says:

> The steepest slopes occurred for ages 18–22 and lower levels of education

But it's relevant here because most people don't know that general intelligence levels (so far as IQ can measure) have begun to decrease, to the point that the GP here was overtly mocking the mere possibility of such as a [implied] practical impossibility.

Diagnoses for them started to skyrocket. Important difference.

I’m no expert, but I have seen the public education system attacked and defunded for decades, at home and abroad. Even libraries are being shut down in places with enough anti-intellectual sentiment. This goes much deeper than the fluoride in water.

If you can point to IQ values of New York specifically, going down more significantly starting with the introduction of fluoride into the water system, then you might have something there.

Until then, policy discussions like this will continue to take focus from the things that actually have an impact on IQ, like public education, healthcare/nutrition, and poverty.

And I'm certain one could trivially dig up data correlating the decline of IQ in New York to fluoridation. The Flynn Effect reversal began in the 90s, and New York began fluoridating their water in 1965, so there's an excellent age correlation there. But that correlation does not necessarily mean causation. What matters are more controlled studies determining definitively whether fluoride is intellectually harmful by using fluoride levels in urine to control for various confounding variables (people in the same regions getting fluoride from multiple sources, consuming more/less products with fluoride, etc). And we do have those studies, and the answer is yes it is.

That certainly doesn't mean it's the sole cause for the reversal of the Flynn Effect as its seen across the developed world, and many countries do not add fluoride to their water. But it is likely a contributing factor. In recent decades we have begun moving far faster than we're capable of evaluating the consequences of, and long-term consequences may well be stacking from multiple sources of mistakes.

[1] - https://nces.ed.gov/programs/coe/indicator/cmd/education-exp...

This is disingenuous, and itself a political talking point.

> In reality US education spending per student has continually increased and is always near the top of the world.

It is much more nuanced than “money in equals IQ out”.

Where does the money end up? Not in classrooms, unfortunately.

What is the average ratio of teachers to students? Is this number going up, up, up?

Now do counselors, nurses, etc.

How much are teachers spending out of pocket for classroom supplies? Has this number gone down, down, down?

By "most" metrics the US should be having phenomenal educational outcomes. The one variable that's not controlled for is the quality of students. Also, I put "most" in quotes because it's a weasel word - to my knowledge we outperform on every single typical educational metric, except result.

[1] - https://usafacts.org/data/topics/people-society/education/k-...

It’s akin to measuring the reduction in lip skin cancer from drinking sunscreen.

Multiple such studies have been done, globally, over many decades.

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/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.

https://www.cdc.gov/oral-health/data-research/facts-stats/fa...

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-recomm...

It was probably much more effective 50 years ago when fluoride was not in everyone's toothpaste.

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.

So for $15/mo, “problem” solved.

Are you doing that?

I'd love to give it a go for my family

Not really: https://jamanetwork.com/journals/jamapediatrics/fullarticle/...

https://news.ycombinator.com/item?id=43523900

I can only assume once you see those very valid criticisms, you will update your references

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.

  For fluoride measured in water, associations remained inverse when exposed groups were restricted to less than 4 mg/L or less than 2 mg/L but not when restricted to less than 1.5 mg/L

  There were limited data and uncertainty in the dose-response association between fluoride exposure and children’s IQ when fluoride exposure was estimated by drinking water alone at concentrations less than 1.5 mg/L.

Which is not a claim that was being discussed in this subthread, since the original claim being refuted specify any such qualification.

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.

[1] - https://ntp.niehs.nih.gov/whatwestudy/assessments/noncancer/...

> 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.

---

"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.

https://theunbiasedscipod.substack.com/p/the-well-runs-deep-...

The NTP report is flawed and likely biased.