Dear EarthTalk: Why do some people complain about fluoride in drinking water and toothpaste? I thought it was beneficial for dental health?
—Becky Johnston, Shoreline, WA
Communities began adding fluoride to water supplies in the early 1940s after decades of studies into why some Colorado residents were exhibiting a discoloration or “mottling” of the teeth but at the same time very low rates of actual decay. The culprit turned out to be high concentrations of a naturally-occurring fluoride that was running off into the water from Pike’s Peak after rainfalls. Research later concluded that adding small, controlled amounts of fluoride into public water supplies would act as a form of community-wide cavity prevention without causing the undesirable mottling known at the time as “Colorado stain.”
Today, supporters of fluoridation cite research from the U.S. Centers for Disease Control showing that the very inexpensive fluoridation of drinking water has since correlated to significant reductions in incidences of tooth decay (15-40 percent) in communities across the country. But skeptics worry we may be getting too much of a good thing. While small amounts of fluoride will prevent tooth decay, excessive amounts can lead not only to irreversible tooth discoloration (today called “fluorosis”) but also to other health issues, including an increased risk of bone breakage and osteoporosis.
The problem, says Fluoride Action Network (FAN), which is opposed to fluoridation, is that the very water supplies that are treated for dental purposes are also used in the making of many common food products—from baby formula and cereal to juices, sodas, wines, beers and even fresh produce. And with most toothpastes also adding fluoride, many people are ingesting far more fluoride than they should.
The main concern for most people is the discoloration of children’s second teeth once the baby teeth are gone. Besides being embarrassing, there is no cure. And some doctors worry that excessive fluoride may actually be promoting tooth decay rather than preventing it—and harming kids in other ways, particularly as they get older. FAN cites studies showing how low-to-moderate doses of fluoride can lead to eczema, reduced thyroid activity, hyperactivity, IQ deficits, premature puberty and even bone cancer.
On the other side of the debate, concerns have risen that our increased reliance on non-fluoridated bottled water instead of tap water may be leading to increases in tooth decay (some bottled waters have added fluoride). However, speaking in a May 2002 UPI Science News article, John W. Stamm, dean of the School of Dentistry at the University of North Carolina at Chapel Hill and a spokesperson for the American Dental Association, said, “It’s very important to realize that there are many sources for body fluids. The fact that one may be consuming variable amounts of bottled water seems to me to be insufficient reason to be concerned about a fluoride deficient diet.”
Avoiding fluoride is difficult for those whose local water is fluoridated. And the only filters that can strain fluoride out of water are expensive ones that employ reverse osmosis, activated alumina or distillation. Switching to unfluoridated toothpaste—many varieties are available from natural health retailers—is one way to cut down on fluoride intake, especially for those who swallow toothpaste when they are brushing.