Fighting for fluoride in water
Head of Dentistry at James Cook University, Professor Neil Meredith, weighs in on the fluoride debate and decodes the science.
AS Mayor Bob Manning said recently: “Fluoride will be decided by science.”
It only seems appropriate to report on and present the science around Community Water Fluoridation (CWF) in a balanced, informed and understandable way. How does fluoride work? Our teeth and bones are comprised of a crystalline material called calcium hydroxyapatite.
Teeth are dissolved by exposure to acids produced by bacteria feeding on sugary foods.
Such bacteria form plaque on tooth surfaces, leading to cavitation and causing decay.
Teeth develop in our children from before birth until about eight years of age.
In this period, the calcium hydroxyapatite crystals form our teeth and bones.
If fluoride is present in the diet – in food, drinks, water or even toothpaste – it is incorporated into the calcium hydroxyapatite, which becomes calcium fluorapatite, which is less soluble and less easily dissolved, making teeth more resistant to decay.
A secondary benefit is that fluoride washes over our teeth as we drink and is also present in saliva, giving even adults a beneficial topical effect.
Fluoride is present in nature and in many natural springs and water supplies.
The optimal level of fluoride in water is 0.7mg/L and by introducing fluoride into communal drinking water this level is easily controlled.
In natural sources and springs the concentration is uncontrolled and often much higher.
The effect of this can be fluorosis that is evident as mottling of the teeth. Although unattractive, this does not weaken the tooth structure itself.
This is the most common consequence of high levels of fluoride but will not occur in CWF.
Concerns are expressed about possible risks of cancer, neurological disorders and bone fractures associated with fluoride.
However, a large number of highcalibre scientific studies published in peer-reviewed journals have reported that there is no appreciable risk of these conditions.
The few articles describing these issues include other factors that are likely to cause the symptoms described. Examples include brain disorders related to water contaminated with toxic heavy metals, including lead and mercury.
Another example is bone malformation caused by substance abuse from inhaling fluon refrigerant.
Conclusions drawn from such information should be treated with care.
Many health organisations, scien- tific bodies and university groups have studied and reported on the potential benefits and adverse effects of CWF.
These include the World Health Organisation (WHO), Center for Disease Control, National Health and Medical Research Council (Australia), Medical Research Council (UK).
Their conclusions are unequivocal in that community fluoridated water offers substantive benefits in improving oral health and reducing dental decay in children and adults with no appreciable adverse effects.
CWF has also been shown to be of extra benefit in poorer parts of the community.
WHO recommends fluoridation of drinking water as the single most important intervention to reduce dental caries in communities.
More than 80 per cent of the population – 17.5 million Australians – receive CWF. Why not Cairns? This article has been based on a review of 220 scientific papers and publications.
For those who may be interested, the references are available as a PDF by mailing fluoride@jcu.edu.au. Professor Neil Meredith is Head of Dentistry at James Cook University