University of York systematic review (2000)

Bone health – no association between fractures and fluoridated water

In its systematic review published in 2000, the Centre for Reviews and Dissemination (CRD) at the University of York analysed 18 studies designed to identify possible increases in hip fractures associated with the consumption of fluoridated water. (1)

The York researchers’ analysis found a more or less equal number of cases where hip fracture rates increased or decreased slightly in fluoridated areas, with some studies showing no measurable effect either way.

A similar pattern emerged when data from studies on other types of bone fracture (i.e., not hip fractures) was analysed.

In their report the York team say: “A forest plot of all the bone studies showing the measures of effect and their 95% confidence intervals was produced for all studies that provided sufficient data to calculate a relative risk, odds-ratio or standardised rate-ratio and its 95% confidence interval. “

They continue: “The majority of the measures and their confidence intervals were distributed around 1, the line of no effect for related measures (suggesting no association), with no obvious outliers noted.”

Cancer – no pattern of association with fluoridated water

The York team also reviewed studies comparing cancer rates in fluoridated and non-fluoridated areas.

On the basis of their analysis they conclude: “The findings of cancer studies were mixed, with small variations on either side of no effect. Individual cancers examined were bone cancers and thyroid cancer, where once again no clear pattern of association was seen.

“Overall, from the research evidence presented, no association was detected between water fluoridation and mortality from any cancer, or from bone or thyroid cancers specifically.”

1. McDonagh M, Whiting P, Bradley M, Cooper J, Sutton A, Chestnut I (2000): A systematic review of public water fluoridation.  Centre for Reviews and Dissemination, University of York.

YORK’S VERDICT ON BONE FRACTURE STUDIES REVIEWED

“The majority of the measures and their confidence intervals were distributed around … the line of no effect for related measures (suggesting no association), with no obvious outliers noted.”

YORK’S VERDICT ON CANCER STUDIES REVIEWED

“Overall, from the research evidence presented, no association was detected between water fluoridation and mortality from any cancer, or from bone or thyroid cancers specifically.”