Study.

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.
  • sbird@sopuli.xyz
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    19 hours ago

    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

    • CookieOfFortune@lemmy.world
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      15 hours ago

      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.

      • sbird@sopuli.xyz
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        14 hours ago

        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!

        • CookieOfFortune@lemmy.world
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          11 hours ago

          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.

          • sbird@sopuli.xyz
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            10 hours ago

            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.