What the 'York Review' on the fluoridation of drinking water really found

Originally released : 28 October 2003

A statement from the Centre for Reviews and Dissemination (CRD).

In 1999, the Department of Health commissioned CRD to conduct a systematic review into the efficacy and safety of the fluoridation of drinking water. The review specifically looked at the effects on dental caries/decay, social inequalities and any harmful effects. The review was published on the CRD Fluoridation Review website and in the BMJ in October 2000.

We are concerned about the continuing misinterpretations of the evidence and think it is important that decision makers are aware of what the review really found. As such, we urge interested parties to read the review conclusions in full.

We were unable to discover any reliable good-quality evidence in the fluoridation literature world-wide.

What evidence we found suggested that water fluoridation was likely to have a beneficial effect, but that the range could be anywhere from a substantial benefit to a slight disbenefit to children's teeth.

This beneficial effect comes at the expense of an increase in the prevalence of fluorosis (mottled teeth). The quality of this evidence was poor.

An association with water fluoride and other adverse effects such as cancer, bone fracture and Down's syndrome was not found. However, we felt that not enough was known because the quality of the evidence was poor.

The evidence about reducing inequalities in dental health was of poor quality, contradictory and unreliable.

Since the report was published in October 2000 there has been no other scientifically defensible review that would alter the findings of the York review. As emphasised in the report, only high-quality studies can fill in the gaps in knowledge about these and other aspects of fluoridation. Recourse to other evidence of a similar or lower level than that included in the York review, no matter how copious, cannot do this.

The full report is available via the CRD Fluoridation Review website. For more information, please contact Paul Wilson.