The US Government’s National Toxicological Program (NTP) has released a draft of major 6 year review into fluoride’s neurotoxicity. The draft review has been released as the result of a court order. The NTP had advised in 2022 that it was ready to release the review but the final version has been held back due to political interference (see emails released under FOIA). 

The draft review, which includes the peer reviewers comments and the NTP response to those comments, has been used as the major piece of evidence in a two week federal trial that was held in February 2024. Whether the final version is ever released is now not relevant since it has been thoroughly contested in the court. 

A court ruling is expected in the near future (as at 26 April 2024).

The NTP, (est. 1978), is an interagency collaboration within the U.S. Department of Health and Human Services. Is in partnership with:

      • National Institute for Occupational Safety and Health (part of Centers for Disease Control CDC)

      • Food and Drug Administration (FDA)

      • National Institute of Environmental Health Sciences (part of National Institutes of Health NIH)

    The NTP is the Go-To agency when the US Government want to review any “agents of concern”. It does the most serious scientific analysis to identify if there are any toxic or biological effects caused by that agent. 

    Results of the NTP Review

      • The meta-analysis reported that 52 of 55 studies found lower IQ with higher fluoride exposures, 95% consistency. 7 IQ point reduction (SMD-0.46 (-0.55, -0.37)). Page 499 has the 55 Human IQ studies. 1 SMD = standardized weighted mean difference is equivalent to 15 IQ Points. Therefore, -0.46 means 15 x -0.46 = 7 IQ Points. Page 502 has a breakdown of the 55 Human IQ studies with the -0.46 SMD.
      • The NTP recognised that of the high quality studies the Canadian and Mexican cohort data were the strongest. Those studies included Bashash 2017, Bashash 2018, Green 2019, Till 2020, Farmus 2021. Those studies found an IQ reduction range between 3 – 9 IQ points. On average, a 1ppm increase caused a 5 IQ point reduction. Note, in New Zealand we fluoridate at a range of between 0.7ppm – 1ppm which is why it can be said that we maybe lowering IQ in New Zealand between 3 – 5 IQ points on average.

      • Concluded that prenatal and early life exposures can reduce IQ.

      • The meta-analysis could not detect a safe level of exposure.
      • First draft of NTP in 2019 concluded “that fluoride is presumed to be a cognitive neurodevelopmental hazard to humans.”

    Ministry of Health have not reviewed NTP May 2023 Draft.

    Rotorua District Council requested a response to the National Toxicology Program review. On 18 July 2023, the Ministry of Health responded with this letter. The Ministry of Health did not provide an answer to the concerns of the Council with regards to the NTP review. MoH say they have only considered developments up to June 2021 and is still relying on the outdated 2014 New Zealand Report.

    The Chief Science Advisor’s report of 2021 quotes from the 1st Draft of the NTP which says “…when considering all the evidence, including studies with exposures to fluoride levels higher than 1.5 mg/L in water, NTP concludes that fluoride is presumed to be a cognitive neurodevelopmental hazard to humans. This conclusion is based on a moderate level of evidence that shows a consistent and robust pattern of findings in human studies across several different populations demonstrating that higher fluoride exposure (e.g., >1.5 mg/L in drinking water) is associated with lower IQ and other cognitive effects in children.”

    The Chief Science Advisor follows with the comment that “This determination is very clearly dose dependent” which should actually mean we don’t have fluoridation since there is no way of knowing what dose anyone is getting, or more importantly what dosage (mg/kg/day) anyone is getting. 

    1.5 mg/L in water is very close to the target the MoH promotes of 0.85 mg/L, there is no margin of safety of a known neurotoxin.

    But it gets worse. In the 2nd Draft of the NTP Report the scientists reject the claim that neurotoxicity occurs only 1.5 mg/L. On page 318 they say “Several of the highest quality studies showing lower IQs in children were done in optimally fluoridated (0.7 mg/L) areas…many urinary fluoride measurements exceed those that would be expected from consuming water that contains fluoride at 1.5 mg/L.” On page 652 the NTP say “there is no obvious threshold”.

    Fluoride Action Network USA (FAN) Summaries

    Fluoride Action Network USA (FAN) Summaries

    FAN has published some great summaries explaining the details from the NTP Review and the politics around it.

    Fluoride is the New Lead – May 3rd, 2023 | Chris Neurath, Science Director, Fluoride Action Network

    Government Report Finds No Safe Level of Fluoride in Water; Fluoridation Policy Threatened – March 16th, 2023 | Fluoride Action Network

    Suppressed Government Report Finding Fluoride Can Reduce Children’s IQ Made Public Under EPA Lawsuit – March 15th, 2023 | Fluoride Action Network.