Does fluoride do more harm than good?

Monday, March 5, 2007
Last year, we ran a story on the best kind of water to drink — bottled, filtered, or tap — and boy, didn't that cause a stir.

The reason? A little thing called fluoride.

A key assumption we made was that adding fluoride to the water supply was a good thing, but quite a lot of angry letter writers told us they knew different. You see there are a lot of people out there who believe fluoridated water is doing the Australian public more harm than good.

Our reporter Michael Slater is going to take a closer look at the great fluoride debate.

Like any debate there are two sides.

For fluoride fan, Professor Ian Meyers of the Queensland School of Dentistry, the argument is simple — fluoride cuts cavities.

On the other side of the coin is Mark Diesendorf, a professor at the Institute of Environmental Studies at the University of New South Wales. He says there's no real hard evidence that fluoride reduces tooth decay.

"There have been studies that have shown no benefits at all from fluoride particularly on permanent teeth," he says.

Before we go on with this argument we should find out:

What is fluoride? It's a naturally occurring mineral found in water and some foods.

How's it supposed to work? It strengthens the enamel or surface of the tooth making it more resistant to the acid that causes cavities.

How does it get into our water? At water treatment works, like the one where Colin Nicholson is the Treatment Operations Manager. At this plant, water is taken from the nearby Hawkesbury River. After being cleaned with chemicals and filtered, the fluoride is added from this storage tank.

The key issue is how much is added, because fluoride is a poison.

Michael: "Now Colin, this is the fluoride … This is not looking too healthy or safe to me, with a [warning] sign like that."

Colin: "Yeah, but it's a concentrated acid form … by the time we add it at one milligram per litre it's a very minuscule amount and it's quite safe."

To make sure we are getting that tiny amount, Michael took a sample from the treatment plant and another from his own tap for independent testing.

So how were those fluoride levels? We found that both the tap water and the treatment plant water contained 0.9 parts per million of fluoride ions — so they're both exactly the same and it's just what Colin promised at the treatment plant.

Below 0.5 and both sides of the argument agree, fluoride has little effect on our teeth.

But does that mean it's good for us? The anti-fluoride camp says no one has investigated the long-term effects.

"The concern about fluoridated water is long term. People aren't going to drop dead from drinking a glass of fluoridated water, but they could have bone disease and other diseases for ingesting it for years and decades, says Professor Diesendorf."

What Professor Diesendorf is talking about is fluorosis, which can affect the entire body. It damages the bone structure causing pain and brittle bones that fracture more easily. It also damages the surface of teeth leading, ironically, to cavities.

But if you ask the pro-fluoride camp, they'll tell you it's practically impossible to overdose on fluoride.

Professor Meyers: "Dental and skeletal fluorosis will only occur where there's an excess of fluoride. There's no evidence of skeletal fluorosis in any communities that have artificial water fluoridation."

But a recent study by Harvard University in the United States, found a link between bone cancer — or osteosarcoma — and fluoridated water in boys only.

Professor Diesendorf: "If this evidence was seen for any pharmaceutical drug it would be immediately taken off the market, but fluoride is the protected pollutant I'm afraid."

Professor Meyers, on the other hand, says,"In the UK the York review looked at over 200 studies, which compared fluoridated communities and cancers — osteosarcomas — and found no relationship at all."

The fact is both sides of the argument can produce studies to support their view — there's no way of telling what's right. We also don't seem to have much choice because every capital city in Australia except Brisbane has fluoride added to the water supply and pouring out of your tap whether you like it or not.

Michael: "So should you stop drinking fluoridated water? Well I've been drinking it all my life and so far, so good … our public health experts believe the greater good is served by adding fluoride to the water supply."

But if you are concerned about fluoride, here are some alternatives:

  • Use water from rain tanks
  • Use a specialised purifier or reverse osmosis system to remove it from your personal supply
  • Buy specially marked "fluoride-free" bottled water.

The choice is yours.


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