No one wants cavities, and people have been using fluoride for decades as a way to keep their teeth healthy. Though fluoride has made a difference in the teeth of people in developed countries, it is not a cure-all for oral health. There are many dangers involved in overexposure to fluoride, and since it is in public drinking water—and thus in almost everything we drink and eat—having fluoride in toothpaste only increases the likelihood of ingesting too much of this chemical. Children are even more likely to swallow toothpaste, and they are at the greatest risk for enamel fluorosis, which causes white streaks in the teeth and sometimes even mottling of the teeth in its most severe form. Though only a cosmetic issue in all but the extreme cases, enamel fluorosis is still an example of fluoride causing the very opposite of what we use it for: stronger teeth.
Not all effects of fluoride are so innocuous. Skeletal fluorosis can be crippling, and even lead to death.1 One study found that in young boys, fluoride is a risk factor for osteosarcoma, the most common type of bone cancer.2
Some studies have suggested that too much fluoride can lead to an increased risk of disorders affecting teeth, bones, the brain, and the thyroid gland.3 This may be in part because fluoride appears to alter the crystalline structure of bones in such a way that may increase the risk for fracture.4
There is a reason why every tube of fluoridated toothpaste comes with the following warning: “Keep out of reach of children under 6 years of age. If more than used for brushing is accidentally swallowed, get medical help or contact a poison control center right away.” Fluoride can definitely be harmful, and yet most Americans use it every single day. It is essentially industrial waste, yet just because it is used in public water systems, people assume it must be safe.
1 J. Fawell, K. Bailey, J. Chilton, E. Dahi, L. Fewtrell and Y. Magara, Fluoride in Drinking-Water, World Health Organization (2006).
2 Elise B. Bassin, David Wypij, Roger B. Davis and Murray A. Mittleman, “Age-Specific Fluoride Exposure in Drinking Water and Osteosarcoma,” Cancer Causes and Control 17, no. 4 (2006).
3 Dan Fagin, “Second Thoughts about Fluoride,” Scientific American 298, no. 1 (2008).
4 Dan Fagin, “Second Thoughts about Fluoride,” Scientific American 298, no. 1 (2008).