Fluoride is like anything else: it’s good for you in appropriate doses. In doses that are too large, it can be poisonous, especially for children. At appropriate doses, fluoride can strengthen your teeth, preventing cavities and infected teeth. Studies show that people who spent most of their lives drinking fluoridated water have about 30% fewer cavities than those who spent most of their lives drinking non-fluoridated water, and that means fewer fillings and fewer crowns. At higher doses, it can lead to a number of serious health problems and even death.
Anti-fluoride protesters often try to confuse the issue by presenting studies showing injury related to fluoride, but ignoring the dosages involved.
It is true that high levels of fluoride can lead to serious problems, such as thyroid problems or developmental difficulties that may lead to a lowered IQ. However, if we look at a study of thyroid problems related to fluoride, we can see that the levels of fluoride present in drinking water are far in excess of levels used in municipal drinking water. The study looked at children in areas with naturally-occurring fluoride in the drinking water. Some children came from an area where the fluoride level in the water was 2.6 parts per million (ppm). Others came from an area where the natural fluoride levels were 5.7 ppm. The recommended dose for fluoride in municipal water supplies—and what we have here in Denver—is 0.7 ppm. In other words, kids in these areas were exposed to fluoride levels of 4-7 times what is in our water supply. For comparison, the Environmental Protection Agency (EPA) considers fluoride levels of 2.0 ppm as being potentially harmful, and levels of 4.0 ppm are considered toxic. Even the control group in this study had water fluoride levels of 0.98-1.0 ppm, significantly in excess of municipal fluoride levels. And even with these high levels of fluoride, the impact was minor. From the conclusion of the study: “The children with dental fluorosis living in endemic fluorosis areas may not have a frank thyroid disease due to excessive fluorine consumption.” In other words, even these high levels of fluoride only resulted in minor perturbations of the thyroid.
But what about potential brain damage? The most commonly cited study on this issue is a review of Chinese studies conducted by a Harvard researcher. The study looked at people suffering neurotoxic responses to fluoride. Children were drinking water with fluoride levels up to 11.5 ppm, or nearly 3 times the toxic dose! Based on the studies, it seemed that these children did experience brain damage, as measured by results on IQ tests. But when researchers completed analysis, they found, “The estimated decrease in average IQ associated with fluoride exposure based on our analysis may seem small and may be within the measurement error of IQ testing.” Even at 3 times the toxic dose and 16 times the municipal water dose, the impact on IQ is small.
The key to getting the benefits of fluoride for your teeth without risking toxicity for you or your child is to make sure you’re not getting too much fluoride. Most importantly, don’t swallow fluoride toothpaste or mouth rinse. Don’t let a child brush with fluoride toothpaste before they are able to spit the toothpaste out without swallowing.
If you live in an area without fluoridated water, talk to your dentist about fluoride supplementation. Never supplement fluoride without talking to a dentist or doctor first.