In the leadup to the election, RFK Jr. said that removing fluoride from drinking water was definitely on his agenda. 

In an interview with NPR's Steve Inskeep this morning, Robert F. Kennedy Jr. said that the Trump administration, which he will likely be a part of, will recommend removing fluoride from the country’s drinking water...

“We don’t need fluoride in our water,” Robert F. Kennedy said on Morning Edition. “It’s a very bad way to deliver it into our systems.”

I wrote about a study on this topic back in 2019 and David wrote about it more recently looking at some more recent research. For a long time this has been considered a kind of fringe topic chiefly of concern to cranks and crazy people.

Given that president-elect Trump just picked RFK Jr. as the next HHS Secretary, it's worth highlighting a column in the Washington Post which concludes that, on this issue, Kennedy's views aren't crazy at all.

Over the years, research has shown that fluoride is not harmless. Higher levels can lead to problems such as tooth discoloration, bone deformities and thyroid diseases. In recognition of these risks, as well as the fact that most people are now getting fluoride through toothpaste, the Public Health Service lowered the recommended fluoride concentration in drinking water in 2015. In 2019, the CDC urged parents to supervise young children’s use of toothpaste to guard against excessive fluoride ingestion.

Multiple studies also show that neonatal fluoride exposure might interfere with brain development. A JAMA Pediatrics study concluded that Canadian women who drank fluoridated water during pregnancy had children with lower IQ scores at ages 3 to 4 years old. There was no statistically significant effect on girls, but IQ scores of boys born to women with higher fluoride consumption were nearly 4.5 points lower...

A U.S. study published this year in JAMA Network Open found that prenatal fluoride exposure was associated with children developing neurobehavioral problems. Researchers followed 229 women in the Los Angeles area from pregnancy through about the third year of their child’s life and linked higher amounts of fluoride by the expectant mothers to nearly double the odds of the child having problems such as anxiety and emotional instability.

In the US, the decision to fluoridate or not is usually made at the local level, though the state of Hawaii has outlawed it. But some towns and cities including Portland and Wichita have decided not to use it. And its use is much less common in Europe.

Interestingly, most Western European countries, including Denmark, France, Germany, Italy, the Netherlands, Norway and Sweden, have ended public water fluoridation. If Kennedy succeeds in persuading Trump to recommend against fluoridation, he would actually be aligning the United States with peer countries.

There's probably a trade off here. There might be a slight increase in cavities if we stopped fluoridating, but that can be mitigated in other ways (toothpaste, fluoride treatments). On the other hand, if fluoride is impacting IQ, that's something that we likely can't change once it has happened. 

Dr. Wen got some blowback for siding with RFK Jr. but she wrote a follow-up in which admitted she initially planned to write a column blasting his views of fluoridation as some kind of conspiracy theory, but had to change her views when she looked at the studies.

I planned to write a column that would debunk his arguments and explain why fluoridation is sound public health policy.

When I delved into the research, I was shocked: The data clearly indicates that conventional wisdom needs to be revisited.

...the studies demonstrating fluoride’s impacts are well-conducted, peer-reviewed and published in prestigious journals such as JAMA. Earlier this year, the National Toxicology Program, which is part of the Department of Health and Human Services, concluded with “moderate confidence” that fluoride in drinking water is linked with lower IQ in kids...

Something isn’t automatically wrong because I didn’t know about it before or because it’s espoused by people with whom I have other disagreements.

As you can probably guess, this didn't go over well with readers at the Post. The comments section is full of angry progressives who are certain that anything with any connection to the Trump administration must be wrong. I won't bother including them. They aren't worth reading.