Among the controversies around public health, fluoridation of the public water supply ranks second behind vaccination. The nominee for Secretary for Health and Human Services wants to remove it. Is that a good idea?
The major benefit of fluoride is that it dramatically reduces dental cavities in children and to a lesser extent in adults. In 1945, Grand Rapids, MI became the first city in the world to add fluoride to its water. Dental cavities in children living there have dropped by more than 60% since that was done. Calgary and Alberta stopped fluoridation and the rate of cavities in children doubled.
Canadian, Australian, and U.S. dental societies support fluoridation, though most European countries have stopped mandating fluoridation. Most dentists also recommend topical fluoride, including fluoride in toothpaste, which fights plaque but does not reduce cavities.
What are the hazards? Very high levels of fluoride can lead to bone disease and staining of teeth.
(I must note that very high levels of almost anything can be harmful. Marathon runners and others have died from drinking too much water).
The biggest concern is that studies have suggested that when mothers drink fluoridated water, their children have lower IQs. These studies were done in regions of Asia and Mexico where naturally occurring levels of fluoride in water are very high. None were done in U.S. communities that had fluoridation programs.
Good studies show that there is no harm to animals or humans from levels up to 10 times the usual consumption of fluoride.
The FDA has recommended a very conservative level of 0.7 mg/liter in the public water supply, a level that maximizes benefit while minimizing risk. In the U.S., about 85% of communities fell in that range.
How can you know? In most of the U.S. and Canada, fluoridation is a local decision. Call your town’s Department of Public Works. If your town adds fluoride they should know, and indeed should publish that data annually. Not every state requires fluoride to be added, and if it is not added testing will probably not be done.
If you use well water, you can arrange for private testing.
What about fluoride in toothpaste? If it is not swallowed, very little gets into the body. If you have children too young to follow the advice not to swallow, put a very small amount (less than 1/8 inch) on the toothbrush yourself.
If you are pregnant and worried, you can buy deionized water to drink during your pregnancy.
So, proven benefit for children’s teeth or very unlikely effect on their IQ? You decide.
Edward Hoffer MD is Associate Professor of Medicine, part-time, at Harvard.
What Does The Doctor Say?
By Dr. Edward Hoffer