The facts on fluoride

"Dietitian Caitlin Reid reveals everything you need to know about fluoride – where it’s found, why it’s in our water, and how much of it you need every day.

Fluoridation of drinking water in regions throughout Queensland and Victoria has had much media coverage this year. While the World Health Organisation (WHO) calls water fluoridation ‘the single most effective public health measure of reducing dental caries across the population’, many people believe it is a form of mass medication and that people should have a right to choose.

What is fluoride?

Fluoride is a natural occurring substance found in plants, fruit, vegetables, tea, rocks, water sources, seawater and soil. It is also present in the air due to natural sources, as well as through industrial or agricultural activities. Fluoride is produced from coal-fired barbecues, and is also contained in cigarette smoke.

Why is it added to water supplies?

Interest in water fluoridation began in the early 1900s when a Colorado dentist noticed his patients had very little tooth decay, which he attributed to the high fluoride content in their water supply. In 1945, the first water fluoridation project commenced in Grand Rapids Michigan, with other trials following soon after. These studies showed dramatic reductions in dental caries with no adverse health effects. Many countries now practice water fluoridation, which has been shown to reduce dental caries by 20–40%.

Fluoride combats tooth decay in two ways – it strengthens the tooth enamel (the hard shiny covering on your teeth) and allows the teeth, damaged by acid, to repair. Fluoride cannot fix dental caries, but can reverse low levels of decay.

Which Australian water has added fluoride?

Beaconsfield in Tasmania was the first town to have fluoridated water, and many other cities followed over the next couple of decades. By 1977 all Australian capital cities, except Brisbane, had fluoridated water supplies. Today, almost 80% of Australia has access to fluoridated water. The rate of fluoridation ranges widely – from 5% in Queensland to 100% in the ACT.

Does fluoride change the taste of water?

Fluoride does not have any taste or smell, therefore fluoridation does not alter either of these. Boiling water will not change its fluoride content. Most home water filtering systems, except the reverse osmosis water filter, do not change fluoride content.

How much do I need?

Fluoridated water contains less than one part per million of fluoride, which equates to 1mg per litre. This level is considered to be safe by the Centre for Disease Control and Prevention (CDC).