No health risks from fluoride, study finds

06:39, Aug 22 2014

Top scientists are advising towns without fluoridation they would be better off adding fluoride to their water supplies.

This follows a review of scientific evidence which found fluoridation levels in this country created no health risks and provided protection against tooth decay.

The review was commissioned by Sir Peter Gluckman, the Prime Minister’s chief science adviser, and Royal Society of New Zealand president Sir David Skegg at the request of Auckland Council on behalf of several councils.

The review, published today, found no evidence of serious adverse effects after many decades of exposure.

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‘‘Communities that currently do not provide CWF (community water fluoridation) – particularly those with high dental caries prevalence – would benefit from its implementation.’’


Councils with CWF schemes could be confident they were reducing health inequalities and saving on lifetime dental care costs for their citizens.

‘‘Councils where CWF is not currently undertaken can confidently consider this as an appropriate public health measure, particularly those where the prevalence and severity of dental caries is high,’’ the report said.

To carry out the review, scientific literature was evaluated by a panel of five experts, along with former Wellington Mayor Kerry Prendergast. The report was reviewed by three international experts and the director of the National Poisons Centre.

In a letter to Auckland Council chief planning officer Dr Roger Blakeley, Gluckman and Skegg acknowledged fluoridation aroused passions and argument.

‘‘Given the caveat that science can never be absolute, the panel is unanimous in its conclusion that there are no adverse effects of fluoride of any significance arising from fluoridation at the levels used in New Zealand.

‘‘In particular, no effects on brain development, cancer risk or cardiovascular or metabolic risk have been substantiated, and the safety margins are such that no subset of the population is at 

risk because of fluoridation,’’ Gluckman and Skegg said.

‘‘We conclude that the scientific issues raised by those opposed to fluoridation are not supported by the evidence. 

‘‘Our assessment suggests that it is appropriate, from the scientific perspective, that fluoridation be expanded to assist those New Zealand communities that currently do not benefit from this public health measure – particularly those with a high prevalence of dental caries.’’

More than half the population get water from a fluoridated supply, including residents of Wellington and Auckland. Places without fluoridation include Christchurch, Whangarei, Tauranga, New Plymouth, Napier and Nelson.

Hamilton restarted putting fluoride in its water last month, having decided to remove it in June last year. The change of heart followed a referendum last October in which about 70 per cent of those who voted were in favour of fluoridation. Organisation Safe Water Alternative NZ is challenging the move, with a High Court hearing scheduled for next month.

Court action against South Taranaki District Council earlier this year by another anti-fluoridation group, New Health New Zealand, was unsuccessful.

New Health challenged the council’s power to add fluoride to the water in Patea and Waverley, but the High Court rejected its application and ruled the law provided implied power to fluoridate. The ruling has been appealed.

In the most recent incident Rotorua District Council decided by seven votes to six not to hold a binding referendum on adding fluoride to the town’s water supply. NZ Dental Association chief executive Dr David Crum said it was a sad day and an example of the flawed local decision-making process affecting ‘‘rational and essential community health actions’’.

The dental association supported efforts by Local Government NZ to have central government take over responsibility for decisions about fluoridation.

The Government is reluctant to get involved, with Health Minister Tony Ryall saying it was a long term position that fluoridation of water supplies was a decision for local communities.

He made those comments last November and yesterday a spokeswoman said the position had not changed.

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