Fluoride in water helps protect people’s teeth, especially in areas with limited access to dental care. However, too much fluoride can cause health problems. So, how do I keep my family’s teeth healthy without risking anyone’s overall health? At NCOHC, we think community water fluoridation is an important part of the answer to this question.
In this post, we dive deep into the science behind fluoride to answer questions about what it is, its safety and health impacts, and how you can be sure your water is OK to drink.
What is fluoride?
Fluoride is a natural mineral that helps prevent cavities. It is spectacularly effective when it comes to dental health—in fact, many public health professionals consider water fluoridation to be one of the single most effective public health measures to prevent tooth decay and improve oral health.
How does it work?
First, it’s important to understand how tooth decay happens. We get cavities when the outer coating of our teeth—the enamel—breaks down and lets harmful bacteria eat into our teeth. When bacteria reach the root of a tooth, you can end up with a toothache that may require a costly (and uncomfortable) root canal to repair the damage.
Many things can degrade tooth enamel over time. Sugar is a big one. When we eat sugary foods, bacteria convert those sugars into acids that eat away at our enamel. But even if we all adopted a sugar-free diet tomorrow, anything from teeth grinding to acid reflux, citrus, and starchy foods would also cause decay.
When that decay happens, fluoride is a great tool to re-strengthen our teeth and prevent decay from turning into a cavity. When we drink fluoridated water or brush with fluoride toothpaste, the mineral bonds with calcium and phosphate in our teeth to re-strengthen our enamel. When used regularly, fluoride-strengthened teeth are better able to resist acid damage that leads to cavities.
Did you know? Fluoride occurs naturally in many foods we eat.
Imagine this: you start your day with a breakfast of coffee and oatmeal. For lunch, you have a hearty salad with spinach, raisins, apples, and a boiled egg. Mid-afternoon, you need a caffeine boost, so you have a mug of black tea. Finally, for dinner, you cook a nice meal of shrimp and roasted potatoes, which you eat with a glass of wine.
Every single food you ate, plus that glass of wine, contained naturally occurring fluoride. But here’s the catch. You can eat shrimp, potatoes, and boiled eggs all day and drink coffee, tea, and wine to your heart’s content. If you only ate foods that naturally contain fluoride, you’d never come close to consuming enough to risk fluoride toxicity, even if you washed it all down with fluoridated water and brushed before going to bed with fluoride toothpaste.
Is fluoride safe?
Just because fluoride is good for our teeth doesn’t mean it’s good for the rest of our bodies, right? Here’s the truth: in high quantities, fluoride can damage our teeth and bones. However, in the United States, fluoridated water and products like toothpaste are regulated to ensure levels never come close to being dangerous.
There are two ways that fluoride can be harmful. The first and most dangerous is fluoride poisoning. We’ll tackle this first, and then we’ll talk about fluorosis.
For context in this section: The standard for water fluoridation, as defined by the US Public Health Service, is 0.7 mg/liter.
Fluoride poisoning
Fluoride poisoning is extremely rare. If you have it, you’ll experience abdominal pain, nausea, vomiting, weakness, and, in serious cases, cardiac arrest. To experience fluoride poisoning, the average adult in the United States (weighing around 180 pounds) would need to ingest one gram of sodium fluoride all at once. That means drinking a total of 386 gallons of water within a few minutes.
Given this, you can start to see how you can eat all sorts of fluoride-rich foods, drink fluoridated water, brush with fluoride toothpaste, and still not come close to a toxic level of fluoride in your body.
Note: In toothpaste, fluoride can often be found in much higher concentrations, which is why we don’t eat toothpaste, and it’s generally a great idea to keep toothpaste out of reach of unattended children.
Fluorosis
Fluorosis is the other negative outcome of over-exposure to fluoride. This one is less damaging but still entirely avoidable while consuming fluoridated water. The EPA recommends fluoride levels in drinking water not exceed two mg/liter for dental fluorosis or four mg/liter for skeletal fluorosis. Compared to the US Public Health Service-recommended 0.7 mg/liter baseline for drinking water, your community’s water system would need to more than double its fluoride concentration to risk fluorosis.
Fluorosis is also a long-term condition, meaning you need to consistently consume over-fluoridated water over many years.
Fluorosis can take two forms. The less severe type, dental fluorosis, is characterized by white spots or other discoloration on tooth surfaces. Dental fluorosis is purely cosmetic and carries no risk of pain or other side effects. However, tooth discoloration can cause low self-esteem and impact overall well-being, and treatment options are available.
The more severe type (brought on by prolonged exposure to more than four times the recommended water fluoridation level), skeletal fluorosis, brings on similar symptoms to fluoride poisoning. People who have consumed very high levels of fluoride for many years may experience abdominal pain, diarrhea, nausea and vomiting, and joint pain. Skeletal fluorosis can also lead to bone brittleness in more severe cases, causing fractures and bone hardening.
How do I know if my fluoridated water is safe?
The CDC maintains a “My Water’s Fluoride” page with county-by-county information about fluoridated water systems, including fluoridation status reports, month-by-month fluoridation levels, and information about natural system fluoride levels (see the next section of this post for more information about well water and naturally occurring fluoride).
If you want to test your tap water, there are many options available. At-home test strips may be less accurate than options to mail a sample to a lab. If you choose to test your water with a mail-in test, you can help ensure reliability by asking about the lab used to test your sample. The EPA requires laboratories to be certified to analyze drinking water samples. Learn more about state-by-state certified laboratories.
What about well water?
If your drinking water comes from a well, you may have one of the many sources of naturally occurring fluoride right in your backyard. Since fluoride is a mineral, underground erosion can release fluoride into your water supply.
While in many cases, naturally occurring fluoride in well water is perfectly safe, this source isn’t strictly measured the way it is in treated municipal water systems. Because of this, if you have a well, you may want to consider testing your well water to know how much fluoride you are ingesting. As outlined above, if your well’s fluoride concentration is above two mg/liter, you run a higher risk of fluorosis.
If your well’s fluoride concentration is too high, you can install a home treatment system to reduce your fluoride levels.
On the other hand, if your community water system or well doesn’t have fluoride, there are also steps you can take to make sure you keep your mouth healthy. Options range from fluoride pills to drops you can add to your water, dietary supplements, and other preventive practices. Your best option if you don’t have fluoridated water is to talk with your dentist about the right choices for you and your family.
Prioritizing & protecting public oral health
At NCOHC, we believe in the power of prevention—and fluoride is one of the best tools we have to stop tooth decay. It can have an especially high impact on communities facing barriers to accessing routine dental care. When used responsibly, fluoride in drinking water is safe and incredibly effective in strengthening teeth and reducing cavities.
Community water fluoridation helps ensure everyone has a fair shot at a healthy smile, no matter where they live. We encourage you to stay curious and informed about your oral health. By testing your drinking water and talking with your dental care provider, you can learn more and make the best decisions for you and your family.
NCOHC, a Foundation for Health Leadership & Innovation program, works to advance systems-level changes, improving the overall health and well-being of all North Carolinians by increasing access and equity in care. Sign up/a> for our monthly newsletter to join the network and get involved!
