Why Is There Fluoride in Water? Is It Effective?

Based on nearly 100 randomized controlled trials, fluoride toothpaste reduces dental cavity rates, but what about just adding fluoride to the water supply?

Like everything in medicine, it’s a matter of balancing the risks and benefits.

This is the first video in a five-part series on water fluoridation. Stay tuned for:
• Side Effects of Water Fluoridation: Dental Fluorosis ( )
• Is Water Fluoridation Safe? ( )
• Why I Changed My Mind on Water Fluoridation ( )
• Medicine’s Response to the Changing Science on Fluoride Safety ( )

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Thanks for watching. I hope you’ll join in the evidence-based nutrition revolution!
-Michael Greger, MD FACLM

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Dave McKinnon

  • @JosephSamuelMusic says:

    How do I get to the other videos in this series?

    • @themotivator2587 says:

      It looks like this is the first, and it came out today. The next four should be released over the next few days.

  • @andrewpawley8883 says:

    I love this channel!

  • @ScarCaskt says:

    If they cared about our teeth, why is dental insurance separate from health insurance?

    • @johnpurser2798 says:

      Who is “they”? And if “they” cared so much about health why have “insurance”? Why not just have health care?

    • @MqKosmos says:


    • @velatoget says:

      @@johnpurser2798 “They” means the people we are talking about. In this case, we’re talking about fluoride lobbyists (people and companies who have financial interest in disposing of their aluminum biproduct for profit), and companies that profit from fluoride directly.

      “Who is they” is a strange question. Does it matter?

    • @pdblouin says:

      ​@@velatoget You’re saying Big Fluoride is the reason we have separate dental insurance? But what about Big Dentist? Aren’t they lobbying for worse teeth?

    • @johnpurser2798 says:

      @@velatoget Well you care who “they” are and what “they” believe so yes, who they are matters. And since you still don’t know who “they” are and the “they” you identified is not who we’re talking about I would guess the topic still needs clarification.

      The video is a nice presentation on the facts of the matter, independent of what any hypothetical “they” wants.

  • @houseofroos says:

    Thank you so much for doing this topic

  • @tommanley2924 says:

    Why, because they had a ton of after product called fluoride and they needed a way to profit from it, that’s how it happened.

  • @Mr.N0.0ne says:

    I appreciate the information, but I find this tactic of pausing the story at the good part and making us come back another day for the rest of it really annoying. I don’t know any other YouTuber that does this. I guess you do it to try to increase subscribers, but I find it unpleasant.

  • @mchagawa1615 says:

    Thank you for sharing <3

  • @sinun82 says:

    The words “safe and effective” have been abused lately

  • @johnpurser2798 says:

    Some of the first conspiracy theories I heard on the internet were based on “Water fluoridation makes you a slave!” I had no idea the roots of this nonsense went back so far.

  • @keithlb1 says:

    I don’t use fluoridated toothpaste because if you are eating cruciferous veggies to reduce high blood pressure and heart disease, the Esselstyn heart reversal diet, he says fluoride interferes with the breakdown of nitrites as you chew these greens with some balsamic vinegar for optimal nitrate absorption into the endothelial tissue

  • @Typhoonbladefist says:

    I did some calculations years ago and came to the conclusion that 2L of tap water per day could result in hypothyroidism. Not long after, I remember coming across a study from, I think the CDC, which came to the same conclusion and suggested lowering the recommended levels added to the water supply. 2L a day is easily obtainable and easily exceeded for those that exercise or work in hot regions. Then there is the question of natural dietary sources such as fruits and vegetables that may have absorbed it. This was not considered in the overall load.

    Now consider if you make soup with tap water, you are only concentrating the levels more. If you use toothpaste, that also contributes to the load from the small amounts you incidentally swallow while brushing.

    Now imagine you already have hypothyroidism, now you either need to stop drinking tap water or need to up your meds.

    Maybe I’m sensitive, but after a few minutes I feel odd whenever I drink tap water (and certain bottled water brands known for using filtered tap water), a bit like brain fog or something. I really can’t explain it, but I never feel this way with natural spring water. Maybe it’s also the added chlorine?

    I’m fine with toothpaste, that works, and so does eating a healthy diet. Both of these are health choices people can make. The tap water is a health choice you cannot make (not without having to pay the tax of buying bottled spring water) and has demonstrable health effects on people that are NOT communicated to the people. Then there is also the concern of dosing in the same levels for infants as adults which I’m concerned may be an issue as well, as well as the variability of dosage based on things like working in hot areas or frequent exercise.

    I seriously hope you take this into account with your follow up videos.

  • @QuocTaHoang says:

    Finally!!! I waited for a whole year since you first announced about Fluoride bad side effect in Feb 2023.

  • @SALVATl0N says:

    Thank you for covering this topic! I hope you will address the widespread use of fluoride, and if there was an issue, it seems like we would have seen it long ago. I wonder if there’s any thing that we have given humans on such a mass scale as much as fluoride?

  • @ruthohare9840 says:

    Went down that rabbit hole when my daughter was a baby and spoiler warning the costs far outweigh the claimed benefits. There is no way adding it to the water is ethically justified.

  • @Albopepper says:

    At what cost!? Nooo!!! I’m not gonna drink any water til I find out! 🤣

  • @deavman says:

    CDC..safe, effective..misinformation..
    Words that make me go “Hummmm…”

  • @rosariomoschitto4037 says:

    Fluoride is worthwhile when limited to topical application (i.e. toothpaste). Consuming fluoride on the other hand (i.e. drinking water) is more harmful than beneficial.

  • @LeckieInstallsLondon says:

    Whoa what a cliffhanger 😂

  • @JMo268 says:

    It’s a cliffhanger!

  • @jdstep97 says:

    I’m not convinced. I’ll continue avoiding fluoride. Thanks for the information, though, Doc.

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