The claim is made by the pro-vice-chancellor of York University, whose own institute was commissioned by the government in 1999 to review all the evidence.
Prof Trevor Sheldon accuses the government of "one-sided handling of the evidence" that his university gathered for the Department of Health. The Department used the evidence "selectively. . .to give an over-optimistic assessment of the evidence in favour of fluoridation," he says.
The York researchers discovered very little evidence to suggest that fluoride in the water supply is beneficial to our teeth. The rate of dental caries has dropped dramatically both in countries that have added fluoride, such as Germany and Portugal, and those which have not, such as Austria and Sweden.
Ireland, which has fluoridated its water, has one of the highest rates of tooth decay in Europe. One study found that three out of four children in Ireland have tooth decay by the time they reach the age of 15.
The York researchers couldn't find enough evidence to suggest either that fluoridation is safe or dangerous. Campaigners against fluoridation have claimed it can cause bladder cancer and fractures. However, it's wrong for any government to claim that fluoridation is "absolutely safe", either, he says.
Despite the lack of evidence for some of the more serious health claims, it is indisputable that fluoride can cause fluorosis, a disease that damages the enamel of the tooth. The American Dental Association has warned mothers of babies and toddlers not to prepare solids with fluoridated water as it may be bad for the development of the child's teeth.
Perhaps Prof Sheldon shouldn't be so surprised by the government's partiality. Until last year it was funding the British Fluoridation Society!
(Source: British Medical Journal, 2007; 335: 699-708).