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:
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.