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Comment by jedberg | Hacker News Reader

Generally kids don't use toothpaste with fluoride because of the risk of swollowing it. Yes, we know it's bad in high doses, which is why kids toothpaste often doesn't have it. You have to wait until they are old enough to spit when brushing.

In reality what will happen is that rich kids will be just fine because they will get their fluoride treatments at the dentist every six months.

It's the poor kids who will suffer because they don't see the dentist regularly because it's expensive, so they won't get their treatments.

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There is a such thing as baby teeth. Presumably most children learn to brush properly while they still have them. If they do something wrong, they get a second chance when their adult teeth replace them. Why does this even need to be explained?

As for “fluoride treatments”, those are applied to the teeth, not drank. They are not a substitute for regular brushing.

You sound concerned about the kids. We are on the same side. There is evidence that fluoridation level is correlated (dose dependent) with sleep problems, lower IQ scores, early onset puberty and bone cancer in children. There are specific areas outside blood brain barrier that it accumulates to the degree of fluoridation (100x to 200x levels of other tissues), all postmortem tests verify this.

It is true that many studies were at higher doses(2x to 4x), but that should not mean that it is acceptable to intentionally raise fluoride levels to half of harmful levels, because we want to protect teeth.

If you don't want cavities decrease sucrose, brush and floss. Can I brush my teeth with use baking soda, use whatever? Arent they are OUR teeth? What if we find some additive might help some other health issue? Should we add that to everyone's drinking water?

Afaik these findings primarily involve populations exposed to fluoride levels above 1.5 mg/L, which is higher than the 0.7 mg/L recommended for U.S. water supplies. There is insufficient evidence to conclude that fluoride at recommended levels negatively impacts IQ.

At safe levels fluoridation is a public health measure akin to fortifying foods with vitamins (e.g., iodine in salt or folic acid in flour something we do all the time).

> insufficient evidence

That's a very high standard of evidence.

Toxicity testing is often carried out on mice, up to the dosage required for any observable effect. From that safe levels for humans are derived, e.g. the NOAEL (No Observed Adverse Effect Level).

To say that a study done in humans, got observable effects at only twice the intended dose (who knows what the s.d. of the dose is, but anyway) and we conclude there's simply not enough evidence?

Many chemicals have been banned on the basis of far less evidence.

the question is regardless of the stated benefit, dont I still have the right to opt out of this all or nothing additive?

You have the right not to drink tap water of course

Honestly 1.5mg is not that different than 0.7mg..is there some reason to believe a 2X factor makes a big deal? I was expecting to hear of 10x differences or something, but 2x is not much of a factor in these kind of gradient effects.

1.5mg is literally twice the recommended limit. I don't really understand the logic in saying 2x overdosed is negligible. If you consistently eat 2x your daily calories you'll see the results fast. If you drink twice what you can handle, it would be bad. Etc

> Should we add that to everyone's drinking water?

Consider the following: Many water sources have a ton of salts and such in them naturally. Fluoride being one of them. The reason why water fluoridation became a thing in the first place is because it was noticed that higher natural levels of fluoridation resulted in fewer caries.

Water treatment in order to make it safe to drink often involves processes that remove and filter out these minerals and chemicals. Which means said things need to be added back in, as part of the treatment process.

Yes, we should.

What additives am I missing? I want to stay healthy.

Well, we don’t have that many things that can be added to water and have health benefits with basically no downside. Fluoride is one of the few things where it makes sense to do this. (If you are willing to broaden your horizons, you can buy things like iodized salt or golden rice to get the benefits of those. But food, alas, is not a government service.)

Kids until which age? Ime somewhere between 4-5 seem to be perfectly able to spit their toothpaste without swallowing. Guidelines in the EU typically suggest normally fluoride toothpaste in increasing amounts after 4.

Also, fluoride helps with remineralisation when it is used pretty much regularly, not once per 6 months. Fluoride treatments once per 6 months are not gonna bring back the enamel lost.

I do not understand what is the big deal here. In many countries there are specific recommendations wrt to fluoride and kids brushing their teeth that seem to work fine. This seems to be a solved issue in many places in the world without fluoridating water.

The recommendation from doctors is to use a small amount of toothpaste with fluoride. Apparently even if they cant spit yet. I was surprised to be told that, even though there are a ton of fluoride free toothpastes available.

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