A Look at Water Fluoridation Across Different Communities

As promised, I’ve done a quick scan through the science literature in relation to water fluoridation across communities with different levels of treatment.

McDonagh et al. (2000) Systematic review of water fluoridation. BMJ. 321 doi: http://dx.doi.org/10.1136/bmj.321.7265.855

This paper is a great one. Not only does it look at the evidence collected by a wide range of previous studies, it also looks at the quality of those datasets. Some of the low grade papers indeed found positive and negative increases in the rate of cancers (ie. more or less) where fluoride treatment took place. All in all, the only real detrimental impact discovered that held any weight was dental fluorosis, although still the rates of fluorosis varied wildly across the studies.

Dini et al. (2011) Comparison of two indices of caries patterns in 3-6 year old Brazilian children from areas with different fluoridation histories. IDJ. 48. doi: 10.1111/j.1875-595X.1998.tb.00700.x

The authors only looked at the teeth in this study, but it is of no surprise what they found; less tooth decay where fluoridation of drinking supply had covered the community for the longest period.

Whelton (2012) Monitoring the effectiveness of water fluoridation in the Republic of Ireland. Journal of Irish Dental Association. http://hdl.handle.net/10147/236475

Again, tooth decay down, mild fluorosis up. Suggestions include reducing the target amount of fluoride in water from 0.9ppm to 0.7ppm and concerns about the possibility of young children swallowing fluoride toothpaste, which gives them higher doses when they are more susceptible to developing fluorosis.

Chachra et al. (2010) The Long-term Effects of Water Fluoridation on the Human Skeleton. JDR. 89 (11) doi: 10.1177/0022034510376070

The authors here looked at exposure of fluoride on the skeleton. They used bone samples from fluoridated Toronto and from non-fluoridated Montreal to test for likelihood of fracture. In short, they found no discernible difference over the natural variation between individuals (ie. genetics, lifestyle and diet factors).

Parnell et al. (2009) Water Fluoradation. European Archives of Paediatric Dentistry. 10 (3)

This one is similar to the McDonagh et al. (2000) above in that it reviews the quality of previous studies, to a similar affect; fluoridation improves tooth health with the only real negative impact being some cases of fluorosis.

I cannot help but conclude from this quick review that the anti-fluoridation crowd are enthusiasts. They have latched onto a small subject and inflated it beyond all measure. It doesn’t help that fluoridation does indeed have a deep murky socialistic conspiracy past, noting the Chinese fluoride paranoia expressed by Jason Woodforth.

From what I found in Charchra et al. (2010) and on other anti-fluoride sites, talking about fluorosis as a severely detrimental pressure on self-esteem, especially in younger people, I couldn’t help but make a conclusion (and the following, I hope is read by the anti-fluoride fans); this whole hysteria is so pathetically small, when much larger problems exist that cause significant social degradation. Think obesity, drug abuse, inequality, violence and mental health; these things kill people in the millions each year. A youth bullied in the school yard and then at home via the internet. The overweight parents, with two obese children, heading through the checkouts with bottles of fizzy, packages of process food and not a scrap of fresh fruit or vegetables (a sight I saw everyday as an undergrad working in retail). A single mother who cannot afford dental for herself. The isolated alcoholic that the world simple forgot. The waste of food while others starve.

And I’m expected to think a handful of cases of mild tooth discolouration demands so much time and enthusiasm?

Yes, the science concludes that you should watch your child’s intake of fluoride, most notably through ensuring they do not swallow tooth paste or mouth wash. However, with some communities now living with multiple generations of fluoridation cover, where are the masses of dead or dying stupid individuals ruined by fluoride?

On the other hand, we know what obesity, cigarettes, alcohol and illegal drugs do and how many people they are killing. Choose a better target.



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5 responses to “A Look at Water Fluoridation Across Different Communities

  1. An informative post. I got intensive fluoride treatment as a child, it may have reduced my number of dental fillings (the studies you review support that idea) and I’d never heard of fluorosis until you mentioned it here.

    • I’m the same. I hadn’t heard of fluorosis until I looked into the studies.. Seeing I’ve lived in fluoride treated areas for more than 20yrs without hearing of it tells me what the science backs up; it’s unlikely at treatment levels and is only mild in almost all cases (swallowing toothpaste at a young age seems to be worse). But how the anti-fluorides carry on, you’d swear fluoride is a beacon for an alien invasion.

  2. Suggest you read “ Developmental Fluoride Neurotoxicity : A Systematic Review and Meta- Analysis “ published online July 2012 .There are now 36 studies linking fluoride exposure to lowered IQ. There are also now 16 animal studies have found that fluoride exposure impairs the learning and memory capacity of animals – read more on this at – http://www.fluoridealert.org/studies/brain01/
    In July this year researchers from Harvard University, Shenyang Medical University and University of Southern Denmark published a Systematic Review – a Meta- analysis of 27 studies from China and Iran and found strong indications that fluoride can adversely affect cognitive development in children ( lower IQ ). Their review was published in the US govt Journal Environmental Health Perspectives
    The researchers analyzed possible associations with IQ measures in more than 8,000 children of school age up to 14 years of age and apart from one study which had a neutral finding, 26 studies indicated that fluoride exposure may lower IQ.
    Comparisons were made of children living in areas with water naturally contaminated with fluoride ( many of these studies had high fluoride areas with fluoride concentrations that were only modestly 2 , 3 or 4 times that of concentrations in Australian artificially fluoridated water ) compared to reference areas with lower fluoride concentrations ( some “ lower areas “ had fluoride concentrations similar to or just lower than Australian fluoridated water )
    The finding – the higher the fluoride exposure the lower the IQ .
    The average lowering of IQ was – 0.45 SMD ( Standardised Mean Difference ) – this is equivalent to an average lowering of 7 IQ points
    Pages 24, 25, 26 of the Harvard publication lists the fluoride concentrations of the high fluoride and lower fluoride areas ( both study and reference areas were naturally contaminated fluoride). ( Attached extract showing water concentrations )

    One of the studies showed lowered IQ at only 0.88 mg/L ( SE Qld is artificially fluoridated at 0.8 mg/L ) compared to a lower reference level of 0.34 mg/L – NSW VIC TAS ACT fluoridated at 1.0 mg/L )

    Eleven of the 19 water studies had a known single point concentration – most of these ranged from 2 mg/L to just over 4 mg/L ( thus only 2 to 4 times higher than artificial fluoridation in NSW Vic Tas ACT )

    The implications of this study – there is no margin of safety for artificially fluoridated water considering that individuals can drink very variable volumes of water. An individual drinking 4 litres of fluoridated water a day receives 4 times the dose of fluoride as one drinking 1 litre of water per day. An individual drinking 1 litre of water with 4 ppm fluoride, receives the same dose of fluoride as an individual drinking 4 litres of water with 1 ppm fluoride in it.

    The REFERENCE ( lower fluoride) areas had concentrations ranging from 0.34 to 2.35 mg/L – the fluoride levels in the lower fluoride areas averaged approximately 0.6 mg/L so it was not a comparison of HIGH fluoride to NO fluoride , it was a comparison of HIGH fluoride to LOWER fluoride – THE BASELINE WAS ALREADY HIGH If a study had been done comparing 2 – 4 mg /L fluoride against a level of < 0.05 mg/L fluoride ( as Brisbane tap-water was before fluoridation ) the difference in IQ may have been even greater.

    A variety of methods were used to measure intelligence – to be able to compare different ways of measuring IQ the researchers used the Standardised Mean Difference – in this meta- analysis they found a Standardised Mean Difference in IQ score of – 0.45 The study used the units Standardized Mean Difference (SMD) and the study's summary unit is Standardized Weighted Mean Difference. The word Standardized refers to the fact that this is a measure of Standard Deviation. It is not the original units of IQ points. An important reason they did not use IQ points is because different studies used different intelligence scales and ways of estimating intelligence.

    One standard deviation in an IQ scale (or any normal distribution centred on 100) is 15. To convert from SMD to IQ points, assuming an IQ scale that uses a normal distribution, multiply SMD by 15.

    Thus the Harvard study finding of an average – 0.45 SMD – means about 7 IQ points lower in the conventional IQ score we use when they compared high fluoride to lower fluoride areas.
    Study author Grandjean stated. “Fluoride seems to fit in with lead, mercury, and other poisons that cause chemical brain drain,” “The effect of each toxicant may seem small, but the combined damage on a population scale can be serious, especially because the brain power of the next generation is crucial to all of us.”
    After reviewing fluoride toxicological data, the USA National Research Council (NRC ) reported in 2006, "It's apparent that fluorides have the ability to interfere with the functions of the brain."
    If you are not aware of this Infant formula when mixed with fluoridated water delivers 100-200 times more fluoride than breast-milk.
    Elected representatives of a community, who are imbued with the responsibility with making the right decision for all members of that community we believe that no person, no representative, should trade off that fluoridated water might lower tooth decay (by possibly a fraction of a tooth at best) for the risk that fluoridated water could be lowering our children’s IQs.
    The Precautionary Principle should be employed, if there is any doubt, keep fluoride out.
    Authorised by Merilyn Haines on behalf of Queenslanders For Safe Water, Air and Food Inc
    PO Box 149 Archerfield 4108 Mob 0418 777 112

    When you say chinese fluoride paranoia expressed by Jason Woodforth – are you saying that the fluoride chemicals used in Qld are not imported from China ???? ( as waste products of chinese industry ) You should know the silicofluoride chemicals do not exist in nature.

    PS – do you show your name anywhere – I have put mine.

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