What is Fluoride?
Fluoride is a natural mineral found throughout the earth’s crust and widely distributed in nature. Some foods and water supplies contain fluoride.
Fluoride is often added to drinking water and provided through toothpaste. Fluoride varnishes are also applied by dental professionals to reduce tooth decay. In the 1930s, researchers found that people who grew up drinking naturally fluoridated water had up to two-thirds fewer cavities than people living in areas without fluoridated water. Studies since then have repeatedly shown that when fluoride is added to a community’s water supply, tooth decay decreases.
How Does Fluoride Work?
Fluoride helps prevent cavities in two different ways:
- Fluoride concentrates in the growing bones and developing teeth of children, helping to harden the enamel on baby and adult teeth before they emerge.
- Fluoride helps to harden the enamel on adult teeth that have already emerged.
Fluoride works during the demineralization and remineralization processes that naturally occur in your mouth.
- After you eat, your saliva contains acids that cause demineralization -a dissolving of the calcium and phosphorous under the tooth’s surface.
- At other times when your saliva is less acidic it does just the opposite- replenishing the calcium and phosphorous that keep your teeth hard. This process is called remineralization. When fluoride is present during remineralization, the minerals deposited are harder than they would otherwise be, helping to strengthen your teeth and prevent dissolution during the next demineralization phase.
Invisalign patients can also use their Invisalign Aligners with over the counter Fluoride rises to increase the effectiveness of the fluoride rinse by pouring it into the trays!
Fluoride is not only safe, but it is effective and necessary — that’s the conclusion of every major health organization in America. Critics of fluoridation disagree with that conclusion. Let’s examine these claims and look at the evidence.
Claim #1: “Fluoride causes cancer.”
- In 2011, a U.S. study found no link between fluoride and bone cancer. The design of this study was approved by the National Cancer Institute1. The study is considered very reliable because—unlike previous studies—it examined actual fluoride levels in bone.
- In October 2011, after lengthy review, a committee of California’s Office of Environment Health Hazard Assessment voted unanimously that the evidence did not support classifying fluoride as a cancer-causing substance.
Claim #2: “Fluoridation is harmful because it causes a condition called fluorosis.”
- Dental fluorosis is a change in the appearance of the tooth’s enamel surface. Nearly all fluorosis in the U.S. is mild, leaving faint white marking on teeth. It does not cause pain, and it does not affect the health or function of the teeth. It’s so subtle that only a dental professional can correctly identify it.
- Dental fluorosis occurs among some people in all communities, even those that do not fluoridate their local water systems. For example, fluorosis occurs in countries like Norway, which does not fluoridate its public water systems because it occurs naturally.
- Fluorosis results from increased consumption of fluoride, over an extended period of time, while the teeth are developing under the gums. One source is toothpaste, which contains a much higher concentration of fluoride than optimally fluoridated water2. This is why parents of children under the age of 6 are advised to supervise their kids’ tooth-brushing and apply the age-a small smear of toothpaste to the toothbrush.
- A study published in 2010 found that mild fluorosis was not an adverse health condition and that it might even have “favorable” effects on overall health. That’s why the study’s authors said there was no reason why parents should be advised not to use fluoridated water in infant formula.
Claim #3: “Fluoride must pose a danger because there’s a warning label on toothpaste.”
Anti-fluoride groups claim that the existence of this label, required by the Food and Drug Administration (FDA), demonstrates that fluoride poses a danger. But here are the facts:
- In 1996, the ADA reviewed studies and concluded that “a child could not absorb enough fluoride from toothpaste to cause a serious problem” and added that fluoride toothpaste3 has an “excellent safety record.” The American Dental Association (ADA) believes the warning label on toothpaste exaggerates the potential for negative health effects from swallowing toothpaste.
- Every day, millions of Americans use fluoride toothpaste without any negative effect. The warning label simply reflects the fact that:
- The concentration of fluoride in toothpaste is much higher than that of fluoridated water.
- Parents are advised to supervise children’s tooth brushing to prevent swallowing because consumption of more concentrated forms of fluoride when children are young and their teeth are forming can lead to fluorosis.
Claim #4: “Europe doesn’t engage in fluoridation, so why should we?”
For a variety of reasons, European countries employ a number of different means to provide fluoride to their citizens:
- Salt fluoridation is widely used in Europe, and milk fluoridation is used in several countries. In fact, more than 70 million Europeans consume fluoridated salt or milk. Fluoridated salt reaches most of the population in Germany and Switzerland. These two countries have among the lowest rates of tooth decay in all of Europe.
- Fluoridated water is provided to 12 million Europeans, mostly reaching residents of Great Britain, Ireland, Spain and other countries.
- Italy has not tried to create a national system of water fluoridation, for two reasons. First, the drinking of bottled water is well established in Italian culture. Second, a number of areas in Italy have water supplies with natural fluoride levels that already reach the optimal level to prevent decay.
- Technical challenges are a major reason why fluoridated water isn’t common in Europe. In France and Switzerland, water fluoridation is logistically difficult because there are tens of thousands of separate sources for drinking water. This is why these countries use salt fluoridation, fluoride-rinse programs and other ways to get fluoride to their people.
Claim #5: “Fluoride is a by-product of the phosphate fertilizer industry.”
Opponents use this misleading message to associate fluoride with fertilizer and industrial waste.
- Fluoride is extracted from phosphate rock, and so is phosphoric acid—an ingredient in Coke and Pepsi. Neither one of them comes from fertilizer.
- Fluoride is extracted from the same phosphate rock that is also used to create fertilizers that will enrich soil.
- The quality and safety of fluoride additives are ensured by Standard 60, a program commissioned by the Environmental Protection Agency (EPA). Standard 60 is a set of standards created and monitored by an independent committee of health experts. This committee provides regular reports to the EPA. More than 80 percent of fluoride additives are produced by U.S. companies, but no matter where they come from, Standard 60 uses on-site inspections and even surprise “spot checks” to confirm the additives meet quality and safety standards.
Claim #6: “The National Research Council said that fluoride can have harmful effects.”
Opponents point to the NRC’s 2006 report on fluoride as a reason to question water fluoridation, but that misrepresents the purpose of this report.
- The NRC raised the possibility of health concerns in U.S. communities where the natural fluoride levels in well water or aquifers are unusually high. These natural fluoride levels are dramatically higher than the level used to fluoridate public water systems
- The NRC states that its report was not an evaluation of water fluoridation. “…it is important to note that the safety and effectiveness of the practice of water fluoridation was outside the scope of this report and is not evaluated.”
- The Centers for Disease Control and Prevention (CDC) wrote that the NRC’s findings “are consistent with CDC’s assessment that water is safe and healthy at the levels” used for water fluoridation.
Claim #7: “There are highly fluoridated states that have higher decay rates than states where fluoridation is less common.”
It is erroneous to compare fluoridation and tooth decay rates from state to state as proof that fluoridation does not reduce tooth decay.
- Water fluoridation is one important way to prevent tooth decay, but even where it is present, many other factors contribute to rates of decay. For example, research confirms that low-income people are more at risk for decay than upper income Americans. This makes sense because income status shapes how often a person visits a dentist, their diet and nutrition, and other confounding factors.
- Comparing different states based solely on fluoridation rates ignores these key income differences. For example, West Virginia and Connecticut reach roughly the same percentage of their residents with fluoridated water—91 percent and 90 percent, respectively. Yet the percentage of West Virginians living below the poverty line is nearly double the percentage of those living in Connecticut.
- A more reliable comparison would examine decay-related problems of people in the same state and income group. A 2010 New York study did precisely this—comparing Medicaid enrollees in counties where fluoridation was prevalent to enrollees in counties where most communities were not fluoridated. The study found that residents of counties where fluoridated water was rare needed 33 percent more fillings, root canals and extractions than those in counties where fluoridated water was common.
Claim #8: “A Harvard study shows that fluoride and lower IQ scores.”
Claims have been made about fluoride and IQ scores. They are not based on sound science but on flawed studies conducted outside the U.S.
- The “Harvard study” was a review of previous studies on IQ scores for children living in areas of China, Mongolia and Iran where the water supplies have very high levels of natural fluoride. In many cases, these areas had significantly higher levels than those used to fluoridate public water systems in the U.S. — more than 10 times as much as the optimal level used in the U.S.
- The Harvard researchers who reviewed these studies were quoted as saying, “While the studies the Harvard team reviewed did indicate that very high levels of fluoride could be linked to lower IQs among schoolchildren, the data is not particularly applicable here because it came from foreign sources where fluoride levels are multiple times higher than they are in American tap water.
- The studies that were reviewed were observational in nature, were conducted over several decades, and did not account for confounding factors, Neither these studies nor the Harvard analysis can conclude a cause for the change in IQ scores that was observed.
- Between the 1940s and the 1990s, the average IQ scores of Americans improved 15 points. This gain — about 3 IQ points per decade — came during the very period when fluoridation steadily grew to serve millions and millions of additional Americans.
- British researchers who evaluated similar fluoride-IQ studies found “basic errors” and wrote that different data were combined in a way “that does not give a valid or meaningful result.
- For additional information, visit Fluoride and IQs4.
Claim #9: “The government has never conducted a randomized, control study of fluoridation.”
- Numerous clinical studies have proven that fluoridated water protects teeth. Since 2010, studies from Nevada, New York, and Alaska have added to the overwhelming evidence that fluoridated water protects teeth from decay. In 2014, separate studies from New Zealand and Great Britain have added to this body of knowledge.
- A randomized study for fluoridation would require a community to be divided into two groups, where some homes would receive fluoridated water and the others would not. It is logistically unfeasible, if not impossible, to pipe fluoridated water into some homes and not others. That is why we rely on the body of evidence that demonstrates the effectiveness of fluoride, such as those above, and on the randomized clinical trials of toothpaste, tablets and varnish.
Claim #10: “Fluoride can harm plants and animals that live in the wild.”
- The fluoride level in a fluoridated water system is not high enough to harm plant or animal species. And research shows that even high levels of fluoride do not have a toxic effect on plants in ponds.
- The average fluoride level in ocean water is 1.4 milligrams per liter, which is significantly higher than the level used to fluoridate public water systems. No reputable source has identified any negative effects on salmon or other fish that live in the ocean.
- An environmental analyst who reviewed a 1989 study about the spawning habits of salmon criticized its authors for failing to “cite any research at all to substantiate their speculation.” This study failed to rule out the presence of other factors, such as the water turbidity and water velocity near dams.
Claim #11: “Fluoridating water is ‘medicating’ people without their approval.”
- Fluoride is a nutrient, not a medicine. Medicine is used to cure or control a medical problem that has already been diagnosed, such as hay fever or high blood pressure. Fluoridated water is not a cure; it’s a proven way to prevent a medical problem: tooth decay.
- Fortifying drinking water with fluoride is a lot like fortifying milk with Vitamin D. These additives prevent poor health. America has a history of fortifying foods or beverages to strengthen health—for example, adding iodine to table salt, fortifying milk with Vitamin D, and adding folic acid to breads and cereals.