This is factually incorrect. In fact recent studies show that up to 25% of cavities are still prevented by fluoridating water. On top of that, multiple Canadian cities are adding fluoride back in their water after 10 years of having it removed because of excellent evidence that the lack of fluoridation in the water is what led to the increase in cavities in those cities, since they had neighboring cities who kept fluoride in the water during the same period

It's factually correct that too much fluoride is correlated with decreased average IQ.

By "too much" a factor of > 10x western safe levels is meant and by "correlated with" is meant a slew of other heavy metals are generally present.

This comes from studies that look at places in China, in Africa, and elsewhere that have unusally high levels of fluoride and other elements naturally occurring in water or as a by product of other industrial processing going on.

Where the problem lies is in the "fill in the missing line" extrapolations that the anti-fluoride folk do to "conclude" that if really high levels of stuff in water makes you stupid and affects your health then it surely must follow that small amounts make you a bit stupid and a bit unhealthy.

This is despite no such evidence existing even given large western populations with meticulously kept water quality and health records in the UK, Canada, Australia, US, etc.

The G20 recommended fluoride levels are safe by all the evidence to date and work to decrease cavity rates.

What is significant political progress is that such measures are now allowed to be debated if they are justified or not. Western political culture clearly shifted far towards dogmatism and needed a course correction. We shouldn’t be afraid to question scientists and studies.

It is factually correct fluoride can be dangerous and studies have shown that. It is also factually correct fluoride in water reduces cavities. The debate is the risk rewards lines and safety.

https://www.newsweek.com/epa-fluoride-drinking-water-risks-c...

> Federal officials have recommended a fluoridation level of 0.7 milligrams per liter of water as of 2015. This is a decrease from the recommended upper ranger of 1.2 milligrams from the 50 years before that. Meanwhile, the EP has a longstanding requirement that water systems cannot have over 4 milligrams of fluoride per liter of water. For comparison, the international safe limit for fluoride in drinking water as stated by the World Health Organization (WHO) is 1.5 milligrams

The A/B testing you reference in Canada is interesting data obviously. It’s also possible reducing cavities with fluoride comes at an IQ cost isn’t it?