For many decades sodium fluoride, commonly abbreviated to “fluoride,” stood unchallenged as a miracle chemical that protected people from tooth decay.
Every dentist sang its praises, the government poured a bit of it into most of our drinking water sources, and dental product manufacturers included it as the active ingredient in their toothpastes and mouthwashes.
In recent years, however, an increasing number of scientists, researchers, public health professionals and companies have critically examined the beloved dental care ingredient. Studies have questioned whether putting fluoride in our water is safe or effective in reducing cavities. There are now many brands of toothpaste that do not contain fluoride. Instead these manufacturers rely on alternative substances that have not been plagued by controversy.
It’s not that the chemical is inherently dangerous. In small doses it is completely harmless, and there is still plenty of evidence to suggest it can prevent tooth decay. What most critics are concerned with is that consumers are ingesting too much fluoride, which can contribute to medical issues and diseases.
If you want to make an informed decision about your fluoride intake, it’s time to look at all the facts. This topic is especially important for parents with young children whose teeth are still growing.
What Is Sodium Fluoride, and How Does It Work?
Sodium fluoride is a chemical that has positively charged sodium ions bonded with negatively charged fluoride ions. It exists as a dissolvable white powder. If you remember the Periodic Table of Elements from your high school biology class, you’ll understand right away why its chemical structure is abbreviated as “NaF.” You might have seen sodium fluoride supplement tablets that have “NaF” etched into the surface.
When we drink fluoridated water or use dental products with sodium fluoride, trace amounts of the chemical come into contact with our teeth. The substance then contributes to a process called remineralization. It binds minerals — such as calcium and magnesium — to our enamel, the skin of our teeth. This effect defends teeth against acids that contribute to cavities.
Because sodium fluoride is poisonous when consumed in high doses, manufacturers often use it as a key ingredient in pesticides. Its binding properties also make it instrumental for developing preservatives, cleaning supplies, lotion, metal, adhesives, glass and wood-based products such as paper. Most people are only concerned about the adverse effects of ingesting sodium fluoride, so there is little controversy when it comes to its inclusion in non-dental products.
Sodium Fluoride vs. Other Types of Fluoride
“Fluoride” is an umbrella term that generally refers to three types of fluoride additives:
- Fluorosilicic acid [FSA] (sometimes referred to as hydroflurosilicate [HFS]: most common additive in water fluoridation
- Sodium fluorosilicate: dry salt additive, made by neutralizing fluorosilicic acid with sodium chloride
- Sodium fluoride: dry salt additive, can be made by adding caustic soda to neutralize fluorosilicate
FSA has been the primary water fluoridation additive since the 1950s, and about 90% of sodium fluoride in the U.S. is derived from FSA. Sodium fluoride is much more significant as an ingredient in products. Nonetheless, sodium fluoride in our water has been a public health concern as well.
Fluoride Is Actually Natural: A Brief History
Because many fluoride-free brands of dental products call themselves “natural,” there is a misconception that fluoride can only be artificial. Nonetheless, sodium fluoride can also be as natural as the water it flows through. You should keep in mind, though, that natural does not necessarily mean healthy, and vice versa.
In 1931 Dr. Frederick McKay proved that high levels of naturally occurring fluoride in drinking water supplies could cause people to develop permanent brown stains on their teeth. Dentists eventually identified this symptom as part of fluorosis, a condition that is still prevalent today.
After years of more research, the National Institute of Health made a groundbreaking discovery: when administered at a certain concentration, fluoride seemed to reduce the rate of cavities without causing fluorosis. Today the U.S. Public Health Service recommends an “optimal fluoride concentration” of 0.7 milligrams per liter [mg/L] for communities that fluoridate their drinking water supplies.
Fluoride may be natural, but it is true that local water authorities often rely on synthetic processes to boost the amounts we ingest. According to CDC data from 2014, about two-thirds of the U.S. population consumes fluoridated drinking water. Generally this distribution became standard without the expressed consent of citizens. After all, when was the last time you saw fluoride on a ballot?
A Lot of Sodium Fluoride Comes from Fertilizer Mining
Roughly 90% of the fluoride additives used in water fluoridation are a byproduct of mining phosphorite rocks. This substance is ultimately converted to phosphate fertilizers that are valuable in the agriculture industry.
According to a 2018 study published in the International Journal of Hydrology, phosphate mining can negatively impact local sources of water, including drinking water. The practice also tends to have adverse effects on the health of miners.
To produce sodium fluoride, manufacturers first create FSA by capturing fluoride gas released during the mining process. They then add salt or caustic soda to the substance until it transforms into sodium fluoride. It’s certainly not the cleanest or most natural method of producing fluoride.
In his book, “The Fluoride Deception,” investigative journalist Christopher Bryson presents evidence that corporate polluters have lobbied scientists and public health officials to claim fluoride is safe and effective. There has also been an effort to suppress research against fluoridation, according to artist and anti-fluoridation activist Melissa Gallico. Dentists and public health officials are instructed, Gallico explained, to refer to water fluoridation as a simple adjustment of a naturally occurring mineral.
“This sounds a lot less scary than the fact that they are purchasing hexafluorosilicic acid (a substance that eats through concrete) from a fertilizer plant and putting it in the water supply,” Gallico said.
Evidence of Sodium Fluoride Reducing Tooth Decay
Critics of sodium fluoride use have tried to challenge its efficacy by highlighting the fact that many studies in favor of the practice are decades old and relied on outdated methods to gather and analyze data. There have also been accusations of biased research.
Nonetheless, there is modern research supporting the theory that balanced levels of fluoride can insulate teeth without negative side effects. Here are a few recent studies and scientific reviews in favor of fluoride:
- “Personal oral hygiene and dental caries: A systematic review of randomised controlled trials,” Gerodontology, 2018
- “Fluoride: A Review of Use and Effects on Health,” Journal of the Academy of Medical Sciences of Bosnia and Herzegovina, 2016
- “The Effect of 0.2% Sodium Fluoride Mouthwash in Prevention of Dental Caries According to the DMFT Index,” Journal of Dental Research, 2007
- “The preventive effectiveness in reducing tooth decay and decalcification of different concentration of fluoride toothpaste for orthodontic patients,” West China Journal of Stomatology, 2006
Arguments Against Fluoridating Water
In 2015 the U.S. Public Health Service [PHS] lowered its recommended maximum sodium fluoride concentration in drinking water from 1.2 to 0.7 mg/L. The problem is the EPA is only willing to enforce a limit of 4.0 mg/L.
For decades people have been consuming more than the 1.2 and even the 4.0 mg/L limits, according to PHS data. It’s not only water and dental products. Fluoride is often in our food and beverages, including milk.
Because of these levels that exceed the recommended optimal dosage of fluoride, many children might be at risk of developing fluorosis, according to a 2005 study. Even fluoride-loving dentists acknowledge that fluorosis is a serious issue.
There have also been studies and scientific analyses that suggest high levels of fluoride could be linked to hormone disruption, the development of ADHD, bone weakening, adverse effects on neurological development in children and thyroid problems. Researchers need to produce much more evidence before making any conclusions, but the initial findings are still troubling.
These public health concerns galvanized scientists and public health officials to reexamine the issue of whether water fluoridation is necessary to reduce “dental caries,” the scientific term for tooth decay and cavities. In 2015 Cochrane, a reputable organization that assesses the effectiveness of public health policies, determined that there has been “little contemporary evidence” to prove the dental value of fluoridating water, at least for adults. Dr. Hardy Limeback, who has spent more than a decade researching fluoride, estimated that the chemical saves about half a tooth per person over the course of a lifetime.
Because of the ubiquity of dental products that contain fluoride, it is possible that water fluoridation has become unnecessary, perhaps more harmful than helpful. Since 1975 many countries that do not fluoridate their water have also seen a reduction in tooth decay.
Excess sugar consumption is the largest contributor to dental carries, according to the World Health Organization [WHO]. It is possible that reducing the amount of sugar in a diet could prevent far more cavities than applying fluoride.
Is Sodium Fluoride Linked to Cancer?
It is unlikely that sodium fluoride ingestion contributes to the development of any type of cancer, according to the American Cancer Society. A 2016 study concluded that there is no relationship between fluoride consumption and childhood or adolescent osteosarcoma, the form of bone cancer people believed was linked to fluoride. Most modern research supports this assertion.
The myth of sodium fluoride causing cancer arose in 1991 when scientists tested doses of sodium fluoride on rats and found that some males developed osteosarcoma. Since then many studies have shown that this connection does not apply to humans.
You might want to approach similar myths with a healthy skepticism. There is a popular conspiracy theory, for example, that the government uses sodium fluoride to make citizens docile and easy to control.
Alternatives to Dental Products With Sodium Fluoride
Public health concerns regarding sodium fluoride have paved the way for dental products with alternative ingredients. Since 2011 fluoride-free toothpaste has become particularly popular, and there has been a rise in “natural” brands of toothpaste.
As an alternative to fluoride these companies often use xylitol, a chemical that seems to be able to reduce tooth decay with minimal risks. Some scientists have criticized xylitol and the research around it, but the substance is not nearly as controversial as fluoride. Xylitol is toxic to dogs, so remember to be careful with it if you are a pet owner.
Ron Welch, CEO of dental products company WELDENTAL, claimed that fluoride kills both harmful and beneficial bacteria, some of which is necessary for a healthy mouth. Our bodies need this helpful bacteria to create saliva, Welch said, and saliva can defend against gum disease, a condition that affects roughly half of American adults.
How to Monitor and Manage Your Consumption of Sodium Fluoride
If you’re worried about consuming unhealthy amounts of sodium fluoride, there are many strategies you can use to reduce risks. It is especially important to monitor your children’s fluoride intake. Consult your dentist regarding oral care decisions, but remember they will most likely be extremely biased when it comes to fluoride.
Research or Test the Concentration of Fluoride in Your Drinking Water
Caitlin Hoff, a CDC-certified Consumer Advocate at ConsumerSafety.org, suggested that people who are concerned with sodium fluoride ingestion should try to determine the concentration in their drinking water. Consumers can learn this information by researching local water authorities or testing drinking water samples at a certified laboratory. There are kits people can order and utilize to test the water at home, Hoff said, but there is no guarantee these products will provide accurate results.
If you manage to receive credible results, use them to make decisions about dental care and relevant consumer products. People who are exposed to alarmingly high levels of sodium fluoride in their drinking water sources can invest in water filters and bottled water. Pure Water Freedom, for example, offers a line of fluoride filters.
If You Use Fluoride Toothpaste or Mouthwash, Reduce the Amount
When you brush your teeth, how much toothpaste do you squeeze out of the tube? Like the majority of Americans, you most likely use enough to cover the entire toothbrush, maybe more.
“I’m sure the toothpaste companies love you for using that full one inch of toothpaste on the toothbrush,” said Dr. David Okano, a periodontist with more than 30 years of experience. “But, in reality, a pea-sized amount would be the amount necessary, particularly if you’re a child.”
Using less fluoride toothpaste can reduce the risk of fluorosis, Okano said, not to mention the fact that it will save you money. Many dentists, including Okano, have recommended that children only use an amount of toothpaste that is about as big as a grain of rice.
Dr. Glennis Katzmark, DDS, added that small children are at higher risk for consuming unhealthy doses of fluoride because they tend to swallow more of their toothpaste and mouthwash. Parents can watch out for the health of their children by training them to avoid swallowing.
If you or your family use both toothpaste and mouthwash that contain fluoride, maybe you can go fluoride-free for at least one of those products. One should be more than enough to prevent cavities, especially if your water is fluoridated.
For mouthwash consider a sip instead of a guzzle. This reduction will save money and lower the chance of swallowing sodium fluoride.
When visiting the dentist for cleanings or procedures that involve fluoride, Anastasia Turchetta, RDH, recommended asking for fluoride varnish instead of gel or foam. This approach is likely to reduce the amount of fluoride you might swallow. Turchetta also advised pregnant women to consult their OBGYN about sodium fluoride.
If You Live in a Small Town or Rural Area, Be Extra Careful of Sodium Fluoride in Water
McKay was one of the first dentists to highlight the fact that there are higher rates of fluorosis in small towns and rural areas that do not sufficiently regulate their water supplies. The residents in these vicinities are more likely to have teeth that are darkened and pitted. Katzmark, who grew up in the small town of Cuero, Texas, noticed these stains on her molars and in patients with similar backgrounds.
If you live in a such an area, take extra precautions to protect yourself or family members from the risk of fluorosis. Schedule regular dental checkups and have your children see a dentist at an early age, even if you need to commute out of town to reach an office. Remember that your dental care should be preventative, not reactive.
Try to Improve Your Brushing Techniques and Habits
Regularly brushing and flossing with good technique can be more valuable than toothpaste, according to Okano. Unfortunately the vast majority of dental patients are not doing enough, Katzmark said.
Next time you visit the dentist, try to brush up on your brushing and flossing technique. Most dentists will instruct you to brush twice a day and for two minutes each time. By using proper technique, you won’t need to rely as much on large amounts of toothpaste, and that means less fluoride. To make this adjustment easier, consider ordering some gentle silk floss and a toothbrush with an ergonomic handle.
Fluoride-Free Dental Products
If there is an abundance of sodium fluoride in your water supply, chances are you don’t need it in your dental products. There are dozens of natural toothpaste brands out there, so you will have plenty of choices. For those who still want at least a bit of fluoride, there is always mouthwash.
What’s the Verdict on Sodium Fluoride?
It might be many more years before we can confidently pin down a verdict on sodium fluoride consumption. Right now there is legitimate evidence on both sides of the debate, and it’s difficult to tell which argument is most convincing.
As is the case with many substances, it’s all about balance. You may not be able to snap your fingers and adjust the local water supply, but you can take steps to ensure you are not ingesting an unhealthy amount of fluoride. Whether it’s becoming involved in local politics or simply buying products that reduce fluoride intake, you have the power to protect yourself and impact the issue.
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