This article was first published in聽
聽was about the benefits of water fluoridation. Now, 11 years later, we are back where we started. As the聽, I will try to make the case that fluoride is good for dental health and that it does not affect the brain development of young children.聽
The benefit of fluoride for human health is that it strengthens teeth, makes them more resistant to decay, and has some inhibitory action on the bacteria that lead to cavities. Its聽聽when researchers found that rates of tooth decay varied based on the levels of fluoride in local groundwater. Fluoride is a natural occurring element, but its concentration varies widely in different places. In North America,聽, with the exception of some parts of the southwestern United States where proximity to the聽聽results in very elevated natural levels of fluoride in drinking water.
The decision to supplement drinking water with fluoride in North America led to a dramatic聽聽over the second half of the 20th century and was declared one of the聽聽of the century by the U.S. Centers for Disease Control and Prevention.
Unfortunately, the uptake of聽. Ontario and Manitoba have very high rates, while Quebec and British Columbia have very low coverage.
The opposition to water fluoridation generally follows three main tracks.聽
You will often hear people claim that water fluoridation costs too much money. But聽聽suggest that every dollar spent on water fluoridation saves between $5 and $93 in dental costs. Even by the most conservative estimates, water fluoridation as a prevention strategy saves our society money in the long term.聽
Another argument is we can get fluoride from other sources, like toothpaste. But we add fluoride to drinking water for the same reason we add iodine to salt and folic acid to grains: It is the most effective way to ensure all members of society have equal access to necessary medical care. It is easy to say 鈥済o buy toothpaste鈥� when you have a comfortable income, but access to dental care is a luxury some cannot afford. Fluoride supplementation is not only the most cost-effective way of distributing fluoride to the population, it鈥檚 also the most equitable.聽
The final argument is that fluoride reduces the IQ of children. Many point to a recent review from the U.S.聽聽as proof that fluoride is dangerous. However, this was not new research, but a review of previous trials. Second, its concern was with very high levels of fluoride in drinking water, like places in Texas that are close to the Ogalalla Aquifer, with concentrations above 1.5 mg/L (over twice what is present in our drinking water).
Even so, the studies suggesting an association with lower IQ often compare the average IQ of children in regions with water fluoridation programs against those in other regions, without adjusting for the many other factors that can affect test performance. Also, IQ tests are unreliable predictors of cognitive performance, subject to a number of biases, and are generally poorly regarded these days.
And finally, the studies in question suggest a聽聽with very high fluoride exposure, which is a trivial change in a test that is of dubious value to begin with. Fluorosis, a discolouration of the teeth with exposure to high levels of fluoride, is the only well-established health effect and is cosmetic, not dangerous.聽
The controversy surrounding water fluoridation is unjustified in my opinion.聽, especially in children, although there is limited research on this scenario. Such programs cost money, but they prevent disease in the long term. At times like this, I hope we will not be penny-wise and pound foolish.聽
