Water fluoridation: what we know

So your body is 70 per cent water, but in order to remain adequately hydrated should you opt for filtered or tap? Whether fluoride is good or bad for you occupies centre stage in this debate. The proponents of these two positions seem to inhabit a parallel universe. On the NSW government health website you will find the following quote: “Water fluoridation has been described by the US Centers for Disease Control and Prevention as one of the top ten public health achievements of the 20th century.”

The addition of fluoride to the water and prevention of dental caries in both children and adults are considered a vital proactive health breakthrough with no potential downside. At a dose of 1ppm (one part of fluoride in one million parts of water) the level of fluoride is high enough to look after your teeth but also safe enough to mitigate any adverse effects, according to the NSW health authorities. It’s a practice that receives the thumbs-up stamp of approval from the World Health Organization and numerous health associations around the world, including the American and Canadian dental organisations.

According to the position statement of the American Academy of Nutrition and Dietetics, the fluoridation of community water in the latter part of the 20th century has resulted in a major decline in the prevalence and severity of dental caries in many developed nations, whereby large numbers of both children and adults have been spared the pain and suffering that goes along with this affliction, with the added bonus of considerable financial savings. Estimates in the US indicate that, in most communities, every $1 invested in fluoridation saves $38 or more in treatment costs.

Fluoride acts to enhance the mineralisation of teeth but it also functions to reverse tooth demineralisation and inhibits the acid-producing bacteria that promote dental caries. For adults it is actually the topical application of fluoride found in products like toothpaste that has the most impact. More than the fluoride found in water, this form of fluoridation has a greater capacity to neutralise the harmful bacteria and to contribute significantly to maintaining the healthy mineralisation of teeth.

In late 2013, an article in the weekend Telegraph newspaper revealed the alarming 49 per cent rise in dental caries in young children. While sweet drinks, lollies, cakes and infrequent brushing are contributory factors, the Australian Dental Association also credits this worrying trend to the increased use of bottled water, which lacks fluoride. The article indicates that before fluoride was introduced into the water children would have seven caries on average, which declined precipitously to only one after fluoridation. Now the numbers are rising again and the culprit could be the absence of fluoride.

However, there is a flipside to the fluoride story that speaks to the dangers of fluoride excess. At the level of 1ppm or 1mg/L found in our water, fluoride is considered safe. Once this level goes above 2ppm the danger of dental fluorosis increases and, once the fluoride level exceeds 4ppm, over the course of a lifetime the risk of developing osteoporosis escalates.

Fluorosis is the hypo-mineralisation of tooth enamel that results from excessive fluoride ingestion before tooth eruption in children. It might be hardly noticeable or could lead to white spots, pitting of teeth and discolouration. In recent times its prevalence has increased in many developed nations. In the US, 32 per cent of children now have some form of dental fluorosis.

The problem is that our exposure to fluoride doesn’t only depend on the levels found in water. Toothpaste, foods, medicines and beverages processed in fluoridated areas all contain fluoride. For example, one glass of apple juice will provide 0.2mg/L of fluoride, while a tomato has 0.04mg/L of fluoride. A host of medications, including some of the statin drugs, widely employed to lower cholesterol, are imbued with fluoride (these can be found at slweb.org/ftrcfluorinatedpharm.html).

While some research finds no association between chronic exposure to high levels of fluoride (>3.15 mg/L) and IQ in children, alternative evidence suggests that at levels between 1ppm and 2ppm or above, fluoride might have adverse effects on neurological development. One study revealed a statistically significant increase in the proportion of children with IQ lower than 80 when mean fluoride level in the water was 2.46±0.25 mg/L. Clearly, more investigation is needed in this area.

At concentrations of 0.7–1.2ppm in drinking water, fluoride has anti-cancer effects, but ongoing exposure to higher levels can harm the kidney and the thyroid gland, switch on cells that promote arthritis and raise blood sugar levels. Fluoride can increase free-radical levels, instigate heart disease, damage DNA, stimulate cancer cells and encourage them to multiply. The evidence for this is primarily from test-tube studies and research has yet to confirm a link between fluoride exposure and any human cancers.

There is an extremely vocal anti-fluoride lobby in this country and its poster child is a documentary entitled Fire Water, alkaway.com.au/information-fluoride-documentary.html. In an excoriating reprimand of the health authorities in which, rather than a life-saving health initiative, the fluoridation of our water is portrayed as a health disaster disseminating nothing but toxicity, the narrative is littered with claims of how fluoride might be ruining our health. Details emerge of how the fluoride in our water is derived from the waste produced during fertiliser manufacture and is found in a form called fluorosilicic acid, a substance that has not undergone any controlled human clinical trials documenting its safety or effectiveness.

Despite some, albeit limited, evidence that silicofluoride exposure can raise blood lead levels in children, the American Dental Association and the Centres for Disease Control and Prevention assert that all the chemicals used in fluoridation meet safety standards. However, depending on which universe you want to embrace, there are filtration systems for removing fluoride.

There is no question mark around the life-sustaining essence of water. What lingers under the microscope is a source we can trust.

Dr Michael Elstein is a Sydney-based anti-ageing physician and writer. He is the author of the books Eternal Health: The Comprehensive Guide to Anti-Ageing for the New Millennium and You Have the Power: Why didn’t my doctor tell me about this?