The recent decision by the Hamilton City Council to stop fluoridating the Hamilton water supply has received substantial commentary from my fellow science bloggers regarding the science (or lack there of) behind this decision (see here, here, here, here and here). Most of these posts have addressed some of the dodgy scientific arguments put forward by anti-fluoridation advocates, so I won’t dwell on those – what I want to do here is look at the claim that fluoridation is “mass medication”.
This argument reminds me of the debate over the addition of folic acid to bread. The reason for doing this is that folic acid significantly reduces the occurrence of neural tube defects (NTD) in new born babies. NTD’s can result in death or severe disability for the child. In the debate over compulsory addition of folic acid I originally opposed addition of folic acid, as I thought this means of delivery would lead to doses which varied too much to be useful (some women eat very little bread), and that it was a form of mass medication, particularly as it was only really of use to pregnant women to protect the health of their unborn child – surely it would be far more effective for pregnant women to take supplements ensuring the optimum dose of folic acid to best protect their unborn child?
Thanks to vigorous discussion with colleagues here at sciblogs and other advocates for folic acid, I have since changed my mind (which is something a good scientist/rational thinker should do when confronted with new evidence). The three key points which made me change my mind are:
1) Evidence from countries such as Canada where compulsory fortification of foods with folic acid has lead to a significant decrease in NTD’s
2) Not every pregnancy is planned or recognised in time for the woman to take folic acid for the optimum period of time
3) There were no studies showing that folic acid could be harmful to those taking it in the doses it was being introduced into bread. As is happening in the current fluoride debate some opponents pointed out that with high doses there was some early evidence that it might create some health issues. However, we need to remember that in talking about toxicity or adverse health effects you always need to consider the dosage. Even water, which is vital for live can be toxic if we consume too much of it at one time (rapid consumption of around 2 – 3 litres can cause “water intoxication” which can be fatal). As far as I can see there is little evidence that folic acid (or fluoride) in the doses that are being proposed/used could do harm.
With regards to fluoridation another point worth remembering is that some water supplies have natural levels of fluoride. Indeed it was the observation that populations consuming water with naturally occurring fluoride had lower numbers of dental cavities, that first hinted that adding fluoride to water supplies without it might be a good idea. Can we really consider the addition of something that occurs naturally elsewhere as medication?