What is Fluoride?

The Basics

Fluoride is the term that’s used to describe a chemical compound that exists between the element fluorine (remember the periodic table? Fluorine is element symbol F) and another element. On its own and at room temperature, fluorine exists as a gas (i.e., not a solid or liquid), but it’s actually impossible to find naturally-occurring fluorine outside of a compound:

Because of its reactivity, elemental fluorine is never found in nature […] Fluorine bonds with almost any element, both metals and nonmetals […] It forms covalent bonds with nonmetals, and […] can also form a diatomic element with itself (F2F2) [few elements can do this], or covalent bonds where it oxidizes other halogens (ClFClF, ClF3ClF3, ClF5ClF5). [Fluorine] will react explosively with many elements and compounds such as Hydrogen and water.


Because fluorine can’t be found in the wild, the compound fluoride is totally “natural” (i.e., it occurs naturally). It can also be synthesized (created in a lab environment), however, for use in various applications. Most common interactions with fluoride compounds will occur with public water systems and toothpastes.

The Controversy Around Fluoride

Most of the fluoride backlash that’s happening now is because more and more people have started to learn that fluoride can be pretty nasty when it comes to our health.

Among other things, fluoride is a known (and serious) neurotoxin. What this means is that, under the right conditions, fluoride can cause serious damage to nervous tissue (also called neural tissue or nerve tissue), which is the “stuff” that makes up the nervous system. The nervous system is what regulates our bodies and allows us to function and operate normally (breathe, eat, sleep, move, etc). Therefore, depending on the severity of the toxicity and resulting damage, excessive exposure to any neurotoxin (like fluoride) can be expected to cause significant disruption to a body functioning normally.

When it comes to the neurotoxic effects of fluoride specifically, some studies have shown high enough doses of fluoride can negatively effect parts of the nervous system that correspond to brain function, including memory impairment and increased difficulty in learning (source). Somewhat in keeping with this, there have been some studies done that seem to indicate that excessive exposure to fluoride can cause children to experience development complications, particularly as it relates to neurodevelopment (the creation and growth process of the neurosystem) (source).

Additionally, some concerns have been voiced over the years about a relationship between fluoride and cancer (source), though they tend to be discredited through subsequent studies.

Because of all the potential health risks from overexposure, a fairly large movement has formed across the globe that opposes the use of fluoride, with several different activist and interest groups worldwide fighting its usage in water supplies and dental care products.

If fluoride is so dangerous and toxic, why would anyone choose to expose us to it?

Considering how bad this all sounds, it’s worth contextualizing some of this information. Yes, fluoride is very bad for you, but only if it gets past a certain level.

This definitely isn’t an exact parallel, but consider the following: apple seeds contain arsenic, which is another neurotoxin that can definitely kill you with the right levels of exposure. If you’ve ever had store-bought apple juice in your life, you’ve consumed a low, generally safe level of arsenic (source). In fact, if you were to ingest an entire apple core’s worth of seeds right now, you probably won’t feel much of anything, even though you just put a known, fatal toxin into your body. Will something happen to you internally? Probably! But, given the exposure level, the scale of whatever happens to you will be so minute that the body will be able to recover and heal itself. The body will effectively overcome the neurotoxin, you won’t experience permanent damage to your neurosystem, and you will go about your life without much further thought that you just ate some arsenic as part of snack.

The safety of fluoride is similar to the safety of arsenic. It’s obvious neither are actually “safe” in an absolute sense of a concentrated, undiluted dose. The question is whether you’re getting close to those high concentrations to have to worry.

Many of the alarming results in these studies on fluoride involve exposure to levels of fluoride that you realistically (hopefully) shouldn’t expect to experience. Moreover, it’s worth noting that there are only currently a handful of human studies that point to fluoride as being seriously dangerous or disruptive, and many of the ones that currently exist involve fluoride exposure at levels no government or authoritative body would condone.

By contrast, the United States Health Department, the American and Australian Dental Associations, and countries in Europe and Oceania have repeatedly referenced studies that show that fluoride, at the appropriate exposure levels, is safe and is in fact generally beneficial for human dental health.

Why do some authorities maintain that fluoride is good?

If you love the taste of apple juice, odds are you probably won’t suddenly stop buying it because you’ve learned that it contains arsenic. Put simply, you’ll probably decide that the benefits of your experience of apple juice outweighs the risk of very low-grade arsenic exposure. By the same logic, if there’s evidence to suggest that there are really compelling benefits to small doses of fluoride, authorities will encourage its continued use — at least as long the pros continue to outweigh the cons and the general public’s safety is still ensured.

With that said, there’s actually not nearly as much debate about the use of fluoride in toothpaste (or other dental products) as there is about the use of fluoride in water. Arguably, most people who have done research and genuinely understand the potential threats of fluoride understand that the biggest threat of fluoride use comes from overexposure. Of all the possible places, it’s realistically easiest (and perhaps most likely) to accidentally trigger fluoride overexposure through a miscalculation in how much fluoride should be added to water supplies. Furthermore, it’s highly likely that many people viscerally object to water fluoridation because fluoridated water supplies removes a personal control element that one can have in regulating one’s individual fluoride exposure.

If the debate extends into discouraging the use of fluoridated toothpaste, therefore, it’s often based off location; that is to say, if you live in a place that fluoridates its water supply, you’re more likely to hear an argument against fluoridated dental care products. If you live in a place that doesn’t offer fluoridated water, you probably won’t even think twice about your toothpaste or mouthwash.

Why? Among other reasons, fluoride is one of the most present components in your teeth’s initial development. More importantly, fluoride has been shown to be supremely effective in preventing cavity formation, tooth decay, and permanent tooth loss.

Fluoride in Dental Care

What does fluoride in my mouthwash or toothpaste do?

Fluoride that’s added to dental care products are designed to help treat and protect tooth enamel, which is the exceptionally hard protective outer layer of our teeth that helps prevent them from rotting inside the wet, bacteria-filled places called the mouth. (Fun fact: tooth enamel is the strongest substance in your body. Its structure is made up of mineral crystals that are packed so densely, the final product is harder than iron.)

As we move through the world, eating and aging, our tooth enamel comes under constant fire — sugars; acids; food in between our teeth we don’t brush out that starts to decay; random bacteria from the air we breathe; really, just life — and it doesn’t ever get a break. Its only function is to try to protect your (very important) mouth bones from deteriorating so that you don’t have to consume everything as a liquid for the rest of your life.

(Incidentally, if that did happen, 200 years ago you probably wouldn’t have made it; no Vitamix or Ninja Bullets were around then. Basically, thousands of years of evolution has encouraged our bodies to create a protective film on our teeth so that we don’t die from starvation.)

The longer the fight goes on, the more we wear down our enamel. Eventually, our enamel can completely erode, and then our teeth are exposed to the elements — and they aren’t pretty. In fact, once tooth enamel erodes, there’s no way to regrow it, which means that once your teeth are made vulnerable, they’re pretty much stuck that way. Holes (aka “cavities”) can begin to develop in your teeth that, when left unchecked, can tear through your now-soft teeth and get all the way down to the nerve-endings in your jaw. If you’ve ever had a root canal before, you probably know firsthand how excruciatingly, mind-numbingly painful that can be.

This is where fluoride comes in. For decades, dentists have attested to its efficacy by pointing to all the studies that show fluoride helps strengthen tooth enamel, which it does through the process of re-mineralization. Essentially, in turn hardens the enamel and helps prevents further tooth enamel degradation.

More recently, a German study showed that fluoride might be beneficial for more than the just the process of enamel re-mineralization. Based on the findings, it seems as if fluoride actually reduces the ability for bacteria adhere to hydroxyapatite surfaces (i.e., simulated enamel, since hydroxyapatite is the main inorganic component of tooth enamel, teeth, and bones):

We tested the adhesion of [different bacteria] on smooth, high-density hydroxyapatite surfaces [simulated tooth enamel], [both when] pristine and after treatment with fluoride solution. All bacteria species exhibit lower adhesion forces after fluoride treatment of the surfaces. These findings suggest that the decrease of adhesion properties is a further key factor for the cariostatic effect [effect of inhibiting cavity formation] of fluoride besides the decrease of demineralization.

Basically, it seems as if fluoride helps prevent cavities and dental issues not just through the process of strengthening tooth enamel, but also by protecting it by making it harder for the bad bacteria to stick to your teeth to even start the erosion process.

Are there any natural ways to help protect tooth enamel that don’t involve fluoride?

The good news is that there are a handful of natural things you can do to help mitigate tooth enamel erosion:

  • avoid sugar like the plague.
    Bad bacteria in your mouth LOVE sugar, and those are the bacteria that create acids that erode your enamel. In 2017, the World Health Organization (WHO) released a memo saying that dental cavities “[do] not occur in the absence of dietary sugars.”
  • avoid acidic beverages and acidic/sour foods.
    If you like lemons, limes, cranberries, oranges, or any other variety of citrus fruits (and their bottled juice counterparts); coffee; apple cider vinegar shots; or anything that’s sour, this one’s for you.
  • avoid anything that would cause vomiting or cause acid reflux.
    Since acid is the main culprit for enamel erosion, this should seem pretty obvious. Stomach acid is really aggressive stuff, so you don’t want it near your teeth if you have anything to say about it.
  • stay hydrated.
    Saliva helps to normalize acids that might be in your mouth. If you’re dehydrated, you’re likely going to experience a dry mouth, which will give any acids in your mouth the opportunity to chill out on and between your teeth unchecked.
  • avoid alcohol.
    Alcohol consumption leads to dehydration, which we just covered. Ever had alcohol dry mouth? Now you know it’s doubly gross!
  • don’t brush too hard.
    This might seem odd considering that I just mentioned that enamel is the strongest substance in our bodies, but it’s the same sort of concept as water gradually eroding massive rocks: regular, consistent over the course of several minutes, hours, days, etc will eventually cause wear.
  • floss.
    It may be hard to get into the habit, but flossing involves removing food particles from in between your teeth that would otherwise just decay in your mouth and become a breeding ground for the kind of bacteria you don’t want hanging around.

Fortunately, a lot of the above aligns with living a healthier life in general, so if wellness is your “thing” you’re probably off to a good start. That said, these things are in no way guaranteed to prevent dental problems. Moreover, if you’re looking to ditch fluoride, chances are you’re going to have to do all of these far more religiously than someone who uses fluoride.

There are also other recommendations that you might find on the web for helping improve dental health (“oil pulling” with coconut oil instantly comes to mind, for me), but many of them aren’t yet currently backed by enough scientific studies to indicate they will be a reliable solution.

So if you have a “sweet tooth” that you know for a fact you won’t be able to kick, you probably want to slap some fluoride on it.

Fluoride in Public Water

In 1945, Michigan was the first state in the US (and the first city in the world) to introduce fluoride to its water (source). By 2008, an estimated 64.3% of the total US population was receiving fluoridated water; of the population served by public (i.e., government-maintained, community) water systems, 72.4% received fluoridated water (source). In 2014, the total US population receiving fluoridated water increased to 66.3%, and of the population served by public water systems, 74.4% received fluoridated water (source).

Countries that Fluoridate their Water Supply

Globally speaking, the United States isn’t the only country that fluoridates its water, though it is of only a relative handful. Countries that engage in any amount of water fluoridation are:

  • Australia
  • Brazil (about two thirds of the cities have access)
  • Canada (rates of fluoridation vary by province)
  • China (stopped fluoridating in the 1980s due to some regions having high naturally-occurring levels of fluoride, leading to )
  • Continental Europe
    • only four European Union countries back fluoride on a national scale
    • Germany, the Netherlands and Sweden have discontinued water fluoridation
    • France has never fluoridated its water
    • In Spain, about 11% of the population has access to fluoridated water
    • In some cases, governments have stopped water fluoridation in favor of other methods to improve dental health, such as adding fluoride to salt instead
    • No country has outright banned the practice of fluoridating water
  • Ireland (nearly 75% of the population has access)
  • New Zealand (strongly in favor, most places have access)
  • United Kingdom

Learn About Your Local Water

If you want to learn more about your potential fluoride exposure (and you’re in the United States), you can refer to the US Center for Disease Control’s (CDC) dedicated fluoride index for information on standards for, and surveillance of, current fluoridated water supplies. You can also visit the Environmental Protection Agency’s (EPA) page to learn about ground water and drinking water. You can also learn more about your tap water at the Environmental Working Group (EWG)’s Tap Water Database.

In a nutshell: should you go with fluoride or fluoride-free dental products?

In all honesty, I would say that it’s smart to be concerned about fluoride exposure, because there are real risks at play, and I don’t want to minimize them. That said, I think it’s important to not let panic or simple uninformed fear dictate your decisions.

There is evidence that demonstrates that excessive fluoride exposure can be detrimental to the human the nervous system. There is also evidence that supports that regulated use within a certain range is not just safe, but also immensely beneficial for your dental health.

I’ve tried to give you the basics, but it’s ultimately up to you to do research to help you make an informed decision for your own life. My genetics, diet, past health, location, and everything else in my life present different circumstances for me than yours do for you. These differences may result in different needs when it comes to dental hygiene and/or concerns about fluoride exposure.

Additional Resources

Feel free to use the following links to jump-start your own foray into learning more about fluoride.