K.K. Cheng, Iain Chalmers, Trevor A Sheldon. British Medical Journal, 2007; 335:699-702.

“We are concerned that the polarised debates and the way that evidence is harnessed and uncertainties glossed over make it hard for the public and professionals to participate in consultations on an informed basis.”

Evidence in favour of fluoridation is poor

“Given the certainty with which water fluoridation has been promoted and opposed, and the large number (around 3200) of research papers identified, the reviewers [of the York Review in 2000] were surprised by the poor quality of the evidence and the uncertainty surrounding the beneficial and adverse effects of fluoridation.”

“If fluoride is a medicine, evidence on its effects should be subject to the standards of proof expected of drugs, including evidence from randomised trials. If used as a mass preventive measure in well people, the evidence of net benefit should be greater than that needed for drugs to treat illness… There have been no randomised trials of water fluoridation.”

“Studies that met the minimal quality threshold indicated that water fluoridation reduced the prevalence of caries but that the size of the effect was uncertain.”

“Water fluoridation aims to reduce social inequalities in dental health, but few relevant studies exist. The quality of research was even lower than that assessing overall effects of fluoridation. The results were inconsistent—fluoridation seemed to reduce social inequalities in children aged 5 and 12 when measured by the number of decayed, missing, or filled teeth, but not when the proportion of 5 year olds with no caries was used.”

“The review estimated the prevalence of fluorosis (mottled teeth) and fluorosis of aesthetic concern at around 48% and 12.5% when the fluoride concentration was 1.0 part per million, although the quality of the studies was low.”

Fluoridation may not be safe

“The evidence was of insufficient quality to allow confident statements about other potential harms (such as cancer and bone fracture). The amount and quality of the available data on side effects were insufficient to rule out all but the biggest effects.”

“Small relative increases in risk are difficult to estimate reliably by epidemiological studies, even though lifetime exposure of the whole population may have large population effects.”

“While the quality of evidence on potential long term harms of fluoridated water may be no worse than that for some common clinical interventions, patients can weigh potential benefits and risks before agreeing to treatments. In the case of fluoridation, people should be aware of the limitations of evidence about its potential harms and that it would be almost impossible to detect small but important risks (especially for chronic conditions) after introducing fluoridation.”

Fluoride is not required by the body

“Fluoride is not in any natural human metabolic pathway.”

Medical ethics

“If viewed as a medicine, water fluoridation would require approval from a relevant authority.”

“The legal definition of a medicinal product in the European Union (Codified Pharmaceutical Directive 2004/27/EC, Article 1.2) is any substance or combination of substances ‘presented as having properties for treating or preventing disease in human beings’ or ‘which may be used in or administered to human beings either with a view to restoring, correcting or modifying physiological functions by exerting a pharmacological, immunological or metabolic action.'”

“If fluoride is a medicine, evidence on its effects should be subject to the standards of proof expected of drugs, including evidence from randomised trials. If used as a mass preventive measure in well people, the evidence of net benefit should be greater than that needed for drugs to treat illness. An important distinction also exists between removing unnatural exposures (such as environmental tobacco smoke) and adding unnatural exposures (such as drugs or preservatives). In the second situation, evidence on benefit and safety must be more stringent. There have been no randomised trials of water fluoridation.”

“Under the principle of informed consent, anyone can refuse treatment with a drug or other intervention. … The General Medical Council’s guidance on consent also stresses patients’ autonomy, and their right to decide whether or not to undergo medical intervention even if refusal may result in harm. This is especially important for water fluoridation, as an uncontrollable dose of fluoride would be given for up to a lifetime, regardless of the risk of caries, and many people would not benefit.”

“Potential benefit must therefore be balanced against uncertainty about harms, the lower overall prevalence of caries now than a few decades ago (and smaller possible absolute benefit), the availability of other effective methods of prevention, and people’s autonomy.”

The government has misled the public about the findings of the York Review

“… the Department of Health’s objectivity is questionable—it funded the British Fluoridation Society, and along with many other supporters of fluoridation it used the York review’s findings selectively to give an overoptimistic assessment of the evidence in favour of fluoridation. In response to MRC recommendations, the department commissioned research on the bioavailability of fluoride from naturally and artificially fluoridated drinking water. The study had only 20 participants and was too small to give reliable results. Despite this and the caveats in the report’s conclusion, this report formed the basis of a series of claims by government for the safety of fluoridation.”

“Against this backdrop of one sided handling of the evidence, the public distrust in the information it receives is understandable.”