Is Robert F. Kennedy, Jr., just a big crank? Well, yes. But is he nevertheless correct in his specific claims about the harms of water fluoridation? It’s long been argued that it’s no longer necessary, and that it might have the scary adverse effect of lowering children’s IQs. In this episode of The Studies Show, Tom and Stuart look at the evidence.

While they’re at it, Tom and Stuart ask whether there’s evidence for several other dentistry-related claims. Regular check-ups; flossing; fillings; fluoride toothpaste—is your dentist just b**********g you about any or all of these?

[This podcast was recorded just before Donald Trump selected RFK Jr. as his candidate for US Health Secretary, but that makes the episode even more relevant].

The Studies Show is brought to you by Works in Progress magazine. If you’re an optimist who enjoys reading about how things have gotten better in the past, and how we might make them better in the future—then it’s the magazine for you. Find it at worksinprogress.co.

Show notes

* RFK Jr.’s tweet about how the new Trump administration will remove fluoride from the US water supply

* US National Research Council’s 2006 report on fluoridation

* 2023 meta-analysis on water fluoridation and IQ

* Letter co-authored by Stuart, criticising a bad study on fluoride and IQ in pregnant women and their babies

* The original study

* Review of fluoridation and cancer risk

* 2000 UK NHS review of fluoridation and cancer risk

* 2022 UK Government report on the link of water fluoridation to various different medical conditions

* 2024 Cochrane Review on fluoridation and preventing tooth decay

* Review of guidelines from the Journal of the American Dental Association

* 2020 randomised controlled trial on fillings in children’s teeth

* The Cochrane Library on the evidence for specific intervals between dental appointments (e.g. 6 months)

* The American Dental Association guidelines on flossing, and the NHS ones

* 2019 Cochrane review of RCTs of flossing

* The ADA and NHS guidelines on brushing with fluoride toothpaste

* 2019 Cochrane review on brushing and fluoride

* Claims about cardiac health being related to dental health

* Study of 1m people in Korea on cardiac health and tooth loss

* 2020 meta-analysis of cardiac and dental health

* The study included in the meta-analysis by Chen, Chen, Lin, and Chen

* Claims about dental health and cancer

* 2020 review of the literature

* 2024 Ars Technica story on dentists over-selling their services

* 2019 Atlantic piece: “Is Dentistry a Science?”

* 2013 piece in the Washington State Dental News magazine on “creative diagnosis”

* Articles in the British Dental Journal and JAMA Internal Medicine both arguing that evidence-based medicine has left dentistry behind

Credits

The Studies Show is produced by Julian Mayers at Yada Yada Productions.