Article Review: Sodium Fluoride and the Rat Brain

Ok, you guys are going to start wondering if I actually do any dentistry or if I just spend my time reading irrelevant articles about fluoride.

This will be a quick one because it is just silly.

There is an often-referenced article that found that sodium fluoride (NaF) can damage the rat brain. Sounds scary, right? You can find a link to the original paper on my favourite source for articles on fluoride: https://fluoridealert.org/studytracker/?search=afifi&fulltext=&fantranslation=

The article is from 2009 and is an experiment on 20 rats, split into 4 groups of 5. One group was a control, one group got Vitamin B6, one group got NaF, and another group got NaF and Vitamin B6.

So right off the bat it is rats......and not humans, and very few of them, but the kicker is that these rats were force fed 10mg/kg of NaF daily.

10mg/kg!

Putting that into human perspective.....say you take a 70kg person and have them eat 10mg/kg NaF, you are looking at 700mg daily ingestion of NaF. A child's tube of toothpaste is 75mL and 0.24%NaF, meaning it has about 180mg of NaF in it. So this study would be like force feeding a 70kg human almost 4 tubes of children's toothpaste everyday! Siiiiiiick. This is just plain animal cruelty.

The amounts of NaF in this study simply do not represent realistic human scenarios, and the number of days that the rats were fed wasn't even stated in the article. It is not surprising that the rats were experiencing ill effects. This is such an extreme dosage that it does not even make sense to reference it, but it is cited in dozens of popular articles.

One thing that also gets me about these NaF studies is that the writers only focus on Fluoride, but do not even mention the fact that there is a larger amount of Sodium being administered (by weight). Surely ingesting that amount of Na on a daily basis would have deleterious effects as well. There is no background given on the effects of sodium (even though one of the proposed mechanisms is impairment of a Na/K channel), or any attempt to control for sodium; it is just dealt with as a non-factor, which is not a correct assumption.

Does this article prove that NaF makes rats very sick? Yes. Is it a realistic situation that humans would find themselves in? Not at at all.

Once again, please do not stop brushing your teeth with fluoride toothpaste because of this article.

Thanks for reading!

Dr. Dave