As part of his research into the issue, documentary maker Alistair Harding, contacted both the Ministry of Health and the New Zealand Dental Association (NZDA). The Ministry of Health refused to provide any comment.
However, Dr Robin Whyman from NZDA did provide answers to Alistair’s questions and we find that the answers provide a compelling case that neither the MoH or the NZDA have any credible
evidence on which to base their claims of safety and effectiveness.
Here is a blow-by-blow rebuttal of the Robin Whyman’s answers to questions pertaining to fluoride.
RCR: In your understanding, how does fluoride work?
DR. ROBIN WHYMAN: Fluoride works on the surface of the teeth, especially on the dental enamel, by changing the balance between factors demineralising the tooth surfaces (taking out the calcium and phosphates from the dental enamel) and remineralisation.
Fluoride changes the balance and becomes incorporated in the dental enamel, building a small amount of fluoride into the enamel crystals of the dental enamel and making them more resistant to demineralisation. It also assists remineralisation of dental enamel that has been exposed to acids from the diet.
RCR:Can you talk about the difference between fluoride being used topically, and in our water supply?
DR. ROBIN WHYMAN: Fluoride from the water supply exposes teeth to a low level of fluoride on a frequent basis each day as people drink water and consume other food or drinks made from fluoridated water.
It is also absorbed once swallowed and increases the fluoride levels in saliva by a small amount, increasing the remineralising environment throughout the day.
[Whyman goes on to discuss fluoride toothpaste vs varnishes which is not relevant to this discussion.]
The Ministry of Health recommend adult strength fluoride toothpaste for all ages. Adult strength contains 1000ppm. Fluoride from fluoridated water contains around 0.85ppm and secreted from salivary glands is even less at 0.016ppm. 0.016ppm is approximately 62,500 times less fluoride than 1,000ppm in adult strength toothpaste.
RCR: What are your views on its toxicity?DR. ROBIN WHYMAN: Fluoride consumed in high doses over a very short period can create acute toxicity. This is associated with a number of symptoms but particularly gastric issues such as nausea and vomiting. However, this occurs at levels well above those from fluoridated water or from toothpastes used correctly.
Longer term or chronic exposure to high fluoride levels in early childhood while tooth development occurs can cause dental fluorosis. This is a tooth enamel defect characterised by opaque white areas in the enamel, caused by excess exposure to fluoride while the teeth are forming in the jaws and before they erupt into the mouth. Tooth development occurs during the first 8 years of life; beyond this age children are no longer susceptible to fluorosis.
The New Zealand Oral Health Survey in 2009 showed the overall level of moderate fluorosis to be very low, indicated that dental fluorosis prevalence is not increasing, and that levels of fluorosis are similar between fluoridated and non-fluoridated areas.
Fluoride as used in fluoridated water with a maximum acceptable value of 1.5mg/L (ppm) and recommended level of 0.7-1mg/L (ppm) is not toxic and in New Zealand it is not associated with increasing levels of dental fluorosis.
REBUTTAL: Whyman confines himself to speaking about dental fluorosis as if that is the only consideration of toxicity from fluoride. Dental fluorosis is the first outward sign of fluoride poisoning so should be a huge red flag telling authorities that New Zealanders are receiving dangerous levels of fluoride. To pretend that this damage to the tooth enamel, most probably caused by enzymes poisoned by fluoride, as “merely cosmetic”, as proponents claim, is untrue.
Also untrue are Whyman’s unsubstantiated claims that fluoridated water is not toxic, when recent US Government funded research is finding that it is, and is not associated with increasing levels of dental fluorosis when just about all research on fluoridation shows it is.In fact the Cochrane Collaboration’s Fluoride Review (2015) that the Director General of Health has relied on for directing councils to fluoridate, states that 40% of children in fluoridated areas can be expected to have some form of dental fluorosis and that 12% of children would experience dental fluorosis that could cause concern over appearance when water is fluoridated at 0.7ppm.
RCR: Can you comment on the NTP report and the evidence that opponents of fluoride cite of its toxicity?DR. ROBIN WHYMAN: The National Toxicology Programme (NTP) report was a systematic review of the research on fluoride exposure and neurodevelopmental and cognitive effects in humans. It started in 2016. It has been subject to much ongoing debate and review, including issues of the accuracy and precision of the text. A draft report and meta-analysis of the data was accepted by a Board of Scientific Counselors of the National Toxicology Programme in May 2023. The draft reports were sent to the Director of National Institute of Environmental Health Sciences. It remains for the Director to make final decisions about the recommendations of the report and the meta-analysis. The issue of whether fluoride in drinking water at levels in New Zealand communities with community water fluoridation affect neurological development or IQ was considered by New Zealand’s Chief Science Advisor in his report in 2014.
He reported that in the studies that have raised concerns the fluoride exposures “were many (up to 20) times higher than any that are experienced in New Zealand or other CWF communities, the studies also mostly failed to consider other factors that might influence IQ, including exposures to arsenic, iodine deficiency, socioeconomic status, or the nutritional status of the children. Further, the claimed shift of less than one standard deviation suggests that this is likely to be a measurement or statistical artefact of no functional significance.”
REBUTTAL: Whyman has ignored the findings of the NTP Review. This is a major review containing analysis of many studies, a large number which have been published since 2017. Many of the studies were funded by the US Government and are considered to be very high quality.
The meta-analysis reported that 52 of 55 human IQ studies found lower IQ with high and low fluoride exposures, 95% consistency with an average 7 IQ point reduction.
Of the 19 studies rated higher quality, 18 found a lowering of IQ. The NTP recognised that of the high quality studies the Canadian and Mexican cohort data were the strongest. Those studies found an IQ reduction range between 3 – 9 IQ points. On average, a 1ppm increase may cause a 5 IQ point reduction.
Concluded that prenatal and early life exposures can reduce IQ. The meta-analysis could not detect a safe level of exposure – NO SAFE THRESHOLD OF FLUORIDE IN WATER.
Incredibly, Whyman has chosen to cite the now 10 year old 2014 New Zealand’s Chief Science Advisor’s report to defend fluoridation when there has been a plethora of IQ research that has emerged in the past 10 years.
However, the biggest flaw in the 2014 Chief Science Advisor report which Whyman repeats is that “Further, the claimed shift of less than one standard deviation suggests that this is likely to be a measurement or statistical artefact of no functional significance.”
The original document included the following wording: “Further, the claimed shift of less than one IQ point suggests that this is likely to be a measurement or statistical artefact of no functional significance.”
When the authors of the Chief Science Advisor report were notified that the reduction in IQ related to the 7 IQ points from the Harvard Review in 2012, the authors made the following correction in January 2015:
“Further, the claimed shift of less than one standard deviation suggests that this is likely to be a measurement or statistical artefact of no functional significance.”
One standard deviation is equivalent to 15 IQ points and has been used as a substitute for actual IQ points.
What the Chief Science Advisor’s report should say:
“Further, the shift of seven IQ points suggests that this is likely to be of functional significance.”
The Chief Science Advisor’s report, therefore, should have ended fluoridation.
RCR: How dangerous to children’s IQ do you think fluoride is?DR. ROBIN WHYMAN: The report of the New Zealand’s Chief Science Advisor and Royal Society of New Zealand in 2014 did not support the suggestion that fluoride at the levels used in community water fluoridation is a risk to children’s IQ or their cognitive function. Similarly a 2016 report by the National Health and Medical Research Council (NHMRC) in Australia reviewed the literature. It states “Overall, the body of evidence for an adverse effect of fluoride on IQ and cognitive function is largely of very limited quality and is not particularly relevant to the Australian context. The best and most relevant evidence is from the only high-quality study (Broadbent et al 2014) which found no evidence for an adverse effect of fluoridated water at levels comparable to that seen in Australia on intelligence in children (as measured by IQ).”
The study cited by Broadbent et al is a New Zealand study from the highly reputed Dunedin study. Combined with the wider reviews by the Chief Science Advisor and the NHMRC it gives a strong level of confidence that data in New Zealand does not support the suggestion of a risk to children’s IQ from community water fluoridation in our environment.
REBUTTAL: All of the research quoted above was carried out prior to 2017. In 2017 the first US Government study was published that found fluoride reduces children’s IQ even at the levels we are exposed to with fluoridation. There have been a number of other US Government funded studies carried out in Canada, where around 40% of their water supplies are fluoridated (at an even lower level than in New Zealand). These high quality studies have also found that fluoride at the levels we are exposed to, is neurotoxic.
The NTP Review classified the New Zealand Broadbent study as “low-quality” because basic considerations were not taken into account such as which children, those living in fluoridated or non-fluoridated areas, were taking fluoride tablets.
The NTP Report on Broadbent:
“A frequent, critical limitation among the high risk-of-bias studies was lack of information regarding exposure or poor exposure characterization.
In one case, multiple sources of fluoride exposure were assessed separately without properly controlling for the other sources of exposure, which could bias the results (Broadbent et al. 2015).
“Broadbent et al. (2015) assessed fluoride exposure in three ways: use of community water in a fluoridated area versus a non-fluoridated area, use of fluoride toothpaste (never, sometimes, always), or use of fluoride tablets prior to age 5 (ever, never). The same children were used for each analysis without accounting for fluoride exposure through other sources.”
“For example, there were 99 children included in the non-fluoridated area for the community water evaluation, but there is no indication that these 99 children were not some of the 139 children that had ever used supplemental fluoride tablets or the 634 children that had always used fluoride toothpaste. Therefore, comparing fluoridated areas to non-fluoridated areas without accounting for other sources of exposure that might occur in these non-fluoridated areas would bias the results toward the null.”
See page 66 of the NTP Meta-analysis.