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Fluoride and IQ

One thing everyone agrees on when it comes to the addition of fluoride to drinking water is that the issue stirs up emotions, both pro and con. But the question should not be based on emotion, it should be based on relevant science. Whether fluoride can be used as a rat poison, which in high doses it can, or whether it is produced as a byproduct of the fertilizer industry has nothing to do with its efficacy in reducing tooth decay or with its safety.

One thing everyone agrees on when it comes to the addition of fluoride to drinking water is that the issue stirs up emotions, both pro and con. But the question should not be based on emotion, it should be based on relevant science. Whether fluoride can be used as a rat poison, which in high doses it can, or whether it is produced as a byproduct of the fertilizer industry has nothing to do with its efficacy in reducing tooth decay or with its safety. The allegation that fluoride was initially added to drinking water because this provided an appropriate way for the fertilizer industry to get rid of an undesired byproduct is absurd. Fluoride was added to water because it can reduce cavities. And it does. Bacteria in the mouth digest sugars from food and produce acids that eat away the enamel through a process called demineralization. Flouride, however, can promote remineralization of the enamel and prevent a caity from progressing further. Various studies of fluoridated and non-fluoridated communities since the 1940s have shown that the addition of fluoride to drinking water to the tune of anywhere from 0.7 to 1.2 parts per million can reduce tooth decay in children by some 50%. Today, the comparisons are not as dramatic because many children use fluoridated toothpaste, receive fluoride treatments from dentists and eat processed foods prepared with fluoridated water. In fact, because of these interventions, and the presence of fluoride in drinking water, some children may be getting too much fluoride which can result in fluorosis, a condition that leads to weakened teeth with white streaks. But there are those who claim that the addition of fluoride to water can do more than this, that it can cause cancer, thyroid problems, weakened bones and reduced intelligence.

Fluoride has biological activity so these claims merit attention. And they have received it. In spades. Health Canada, The World Health Organization, The Center for Disease Control and numerous other organizations have scrutinized the many studies that have been carried out and have concluded that the benefits of fluoridation outweigh the risks. They do, however, agree that some children may be getting too much and have suggested that the optimal amount added to water can be reduced to 0.7 ppm and that fluoridated toothpastes which normally contain from 1000 to 1500 ppm of fluoride should be made available in special children’s formulations with about half that amount. The newest bugaboo seems to be the allegation that fluoride can reduce IQ. This is bases on a couple of studies in China comparing performance on IQ tests between communities where the water contained an average of 0.9 ppm and 4.1 ppm of naturally occurring fluoride. The low-fluoride children had a higher IQ on average by 7.7%. Whether this is meaningful is debatable, but 4.1 ppm is four times greater than what is added to water in North America. And the researchers did not check to see if levels of lead, which can certainly affect IQ, in the water were comparable in the two areas. Let’s remember also that poor dental health is not only a cosmetic problem, it has been linked with heart disease. So we want fluoride in our water, but given that we have other sources as well, we perhaps don’t need quite as much in water as previously. Where natural fluoride in the water is greater than 2 ppm, an alternative source of water for children may be appropriate, especially when it comes to making up baby formula. But the anti-fluoride rhetoric is not scientifically justified. And the antifluoride activists can’t accuse me of making these comments because of some brain impairment due to fluoride. Montreal tap water is not fluoridated. And my numerous cavities are a testimonial to that.

 

 

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