The York Review (2000) was the first attempt at a systematic review of fluoridation research by a balanced panel of respected scientists.
No “massive” proof that fluoridation reduced dental decay
It did NOT find fluoridation to be safe
That it was significantly associated with high levels of fluoride
In October 2000, the NHS Centre for Reviews and Dissemination at York University published a report on fluoridation, commissioned by the Department of Health in 1999. It was the first attempt at a systematic review of fluoridation research by a balanced panel of respected scientists, for, against, and neutral on the question of fluoridation. It examined over 3000 studies and found no “A” grade research. All but 214 were rejected as unsound. These unsound studies are still relied on by fluoridation proponents. The remainder were classsed as of “moderate” reliability.
The York Review was called an “independent review”, although it was paid for by the government and carried out by the British NHS, a government body that was already committed to fluoridation. The health secretary who launched it said he wanted a review which would “prove once and for all that fluoride is safe and effective”. In other words, the review’s intended conclusion was decided in advance by a politician.
The York Review’s terms of reference were widely criticised for being too narrow and thus excluding much important evidence against fluoride for example clinical studies. Most of the research on caries levels is epidemiological. Proof of harm, conversely, is almost impossible to prove this way; clinical studies are needed for comparison with epidemiological data.
In spite of this the report found against fluoridation. The response of proponents was to lie about the York findings, claiming they supported fluoridation. The NZ Ministry of Health has joined in promoting such lies to the NZ public. This unconscionable behaviour drew the following public response from Dr. Trevor Sheldon, chairman of the Review Board.
It should be noted in relation to point #1 that the Review Board could find no reliable study showing any benefit from fluoridation. It was obliged by its terms of reference to then consider moderately reliable studies. Even these showed only the 0.6 DMFS (15%) supposed improvement – but that is based on “moderately” reliable studies (primarily Brunelle and Carlos 1990). In fact the range of studies went from a slight benefit through to a slight increase in tooth decay from fluoridation. Proponents continue to quote this as proof that there is benefit from fluoride.
York Science Park
York YO10 5DGProfessor Trevor A. Sheldon
Head of Department
1 Whilst there is evidence that water fluoridation is effective at reducing caries, the quality of the studies was generally moderate and the size of the estimated benefit, only of the order of 15%, is far from “massive”.
2 The review found water fluoridation to be significantly associated with high levels of dental fluorosis which was not characterised as “just a cosmetic issue”.
3 The review did not show water fluoridation to be safe. The quality of the research was too poor to establish with confidence whether or not there are potentially important adverse effects in addition to the high levels of fluorosis. The report recommended that more research was needed.
4 There was little evidence to show that water fluoridation has reduced social inequalities in dental health.
5 The review could come to no conclusion as to the cost-effectiveness of water fluoridation or whether there are different effects between natural or artificial fluoridation.
6 Probably because of the rigour with which this review was conducted, these findings are more cautious and less conclusive than in most previous reviews.
7 The review team was surprised that in spite of the large number of studies carried out over several decades there is a dearth of reliable evidence with which to inform policy. Until high quality studies are undertaken providing more definite evidence, there will continue to be legitimate scientific controversy over the likely effects and costs of water fluoridation.
(Signed) T.A. Sheldon,