Fluoride in Water & Toothpaste: Uses, Dangers & Side Effects [2020 Update]

Fluoride has always been a controversial topic in the world of dentistry, and as a dentist, I’m going to make a bold statement that may surprise you:

I don’t think you need fluoride.

That’s right—contrary to what the CDC, American Dental Association and Academy of Pediatrics say, fluoride is not the miracle of dental health it was sold to be.

The tide may be changing, however.

In an unprecedented decision, a federal judge ordered in November 2019 that a case against the EPA be allowed to go to trial regarding potential dangers of water fluoridation. That trial was set to begin in February 2020, despite the EPA’s insistence that the benefits of fluoride in current levels outweigh any potential harm. It was postponed in late March due to the threat of the novel coronavirus.

I’ve had patients who benefited greatly from topical fluoride application (more on that later). However, on the whole, most people don’t truly need it — especially when it’s ingested via the water supply.

Due to recent advances in dental technology, there’s a better option on the market that not only works better than fluoride but is also non-toxic (and way less controversial).

I raised three daughters without the ingestion of fluoride. That was something I decided back in 1988 when I bought our first water filter. I should also add that each of my daughters grew up without a single cavity.

While many people believe fluoride is perfectly safe and that the water fluoridation controversy has been settled, that’s not the case. In fact, below, I share dozens of peer-reviewed studies that suggest exactly the opposite.

While uncovering the truth about fluoride can be difficult, I’m going to help you unpack the facts.

What is Fluoride?

There are actually many different types of compounds known as fluoride. For example, calcium fluoride is found in well water and soil all over the world in varying degrees, with people who drink from wells in Texas being exposed to higher-than-average levels. Seawater also contains this compound.

Sodium fluoride, on the other hand, is the compound that was originally added to drinking water.

Unlike calcium fluoride, sodium fluoride is greatly absorbed by your body and is not naturally-occurring (read: it’s synthetic). Before it became known as the miracle of modern dentistry, sodium fluoride was just industrial toxic waste.

The third kind of fluoride is most concerning to me, as it makes up 90% of today’s fluoridated water supply in the US. It’s called hydrofluorosilicic acid (HFS or FSA) and is also industrial waste.

Why is it so bad? HFS is typically present with arsenic (a known carcinogen) and leeches lead (also a carcinogen) as it travels through pipes more than other types of fluoride. (Source)

Is Fluoride Safe?

Sodium fluoride, found in toothpaste, can have beneficial effects when used topically. Used in prescription-strength toothpaste, it can support the remineralization of teeth and make it possible to heal cavities.

But in order to get fluoride into teeth, prescription-strength toothpaste is formulated to be acidic. The acid breaks down the tooth so that the amount of fluoride that enters your tooth is greater.

In short: prescription (and sometimes even over-the-counter) fluoride toothpaste can strengthen teeth when applied topically, but at a cost to your enamel.

Unfortunately, fluoride in water isn’t really helpful for preventing cavities and swallowing this chemical causes much more harm than good, as it travels through your bloodstream and to all parts of your body.

For example, fluoride can pass into the brain or the placenta to a fetus when ingested. During breastfeeding, fluoride is also passed from mother to baby and remains in the baby’s system in large quantities, even after weaning.

Since you only get rid of about 50% of the fluoride you consume (through urination), the other 50% sticks around via bioaccumulation anywhere your body stores calcium, like the inside of your teeth, bones, and cartilage. The chemical can also build up in the pineal gland that regulates sleep.

In animals, fluoride accumulation in the brain alters neurotransmitter levels including epinephrine, histamine, serotonin, glutamate, norepinephrine, acetylcholine, and dopamine. Notably, this happens to animal subjects when the amount of fluoride in the blood is similar to that of a human who is ingesting it regularly.

Considering the above facts, it makes you wonder why we’re still adding this chemical to water — especially because there’s no concrete proof that ingested fluoride will even reduce the cavity rate.

Now, at this point, you might be asking the same question I did over 30 years ago, which is: How did this stuff get in our water?

History of Fluoride Use

Fluoride for the teeth was an unexpected discovery made by Frederick McKay, a dentist who spent time in Colorado. In 1901, he stumbled across the fact that the cases of “Colorado Brown Stain” in the many children in Colorado Springs seemed to relate to the strength of the children’s’ teeth, even discolored as they were.

McKay found that fluoride supports the process of remineralization but could also lead to mottled teeth, now known as dental fluorosis. Colorado Springs had a great deal of naturally occurring fluoride in the ground and well water that led to this conclusion.

Then, in 1945, studies in various US cities were conducted between fluoridated and unfluoridated communities. The CDC claims a big victory from these experiments: Apparently, fluoride reduced dental caries (cavities) by 50-70% over the course of 15 years, leading to an official recommendation in 1962 to add fluoride to public drinking water.

However, none of that data referenced in those studies is actually available. In fact, it’s unclear whether the studies were ever completed or well-documented.

The evidence we do have shows us that cavity formation has actually declined equally between communities with and without this compound in their water, which leads me to believe that it wasn’t about the water.

Even when the use of fluoride to reduce cavities has been studied, the quality of research is low-quality and typically shows that if cavity rates decrease, it’s by a small margin.

Yes, cavity rates have declined since the introduction of fluoride in the water supply. However, rates have also declined at nearly identical rates in “control” countries with no public water fluoridation whatsoever.

One study, published in late 2018, did report an increase in tooth decay after fluoride was removed from public drinking water in Juneau, Alaska.

The Fluoride Action Network found several concerning inconsistencies in this research, including failure to include a control population, account for Medicaid reimbursement rates, or consider the unblinded nature of the observations.

The Dangers of Fluoride

According to a review from the University of California in San Diego, industrial fluoride is completely soluble — unlike calcium fluoride that occurs in nature. The review also supports my belief that not only is ingesting this chemical unhelpful for cavities, it’s also dangerous as it accumulates in the body.

The review states,

“Industrial fluoride ingested from treated water enters saliva at levels too low to affect dental caries. Blood levels during lifelong consumption can harm heart, bone, brain, and even developing teeth enamel.”

It’s nearly impossible to track an individual’s fluoride consumption because it comes from so many sources. In addition to tap water, fluoride is found in: (Source, Source, Source, Source, Source)

• foods, like dill pickles
• carbonated drinks
• bottled fruit juice
• canned tomato products
• spinach
• dental products including toothpaste, mouthwash, gels, varnish, and supplements
• the pesticides cryolite and sulfuryl fluoride
• Teflon pans
• medications such as flecainide, niflumic acid, voriconazole, Cipro, and anesthetics

After all, fluoridated water is used to make boxed foods, bottled drinks, and even to water plants!

Now that we know that fluoride is practically everywhere, let’s take a look at some of the specific ways it can cause harm.

1. Fluorosis

Fluorosis is, perhaps, the least shocking but also the most ironic danger. Dental fluorosis is the condition of mottled teeth (appearing as small, white or brown spots on the teeth) that was first defined by Dr. McKay.

The CDC reports that dental fluorosis rates have been rising in the last 30-40 years, likely due to the increase in fluoride sources.

Fluorosis is the only widely acknowledged issue from fluoride exposure — at least according to all governmental bodies. It is thought to impact less than a quarter of people worldwide and typically doesn’t stay on permanent adult teeth, but many adults find that their permanent teeth also show signs of fluorosis.

In countries with very high levels of calcium fluoride in the water, people can develop a severe form of this condition called crippling skeletal fluorosis, which causes bones to become rigid and brittle.

So why do I consider even mild fluorosis to be a major problem?

These discolorations are not just a cosmetic issue. They are indicative of excessive fluoride ingestion, a dangerous practice that is connected to many more severe problems. Plus, areas affected by fluorosis are more prone to developing cavities — decay that can happen in areas of the mouth that are difficult to access, clean, and maintain.

2. Cancer

The research in this area is somewhat inconsistent; however, it seems that fluoride ingestion may impact cancer incidence and/or death from cancer. (Source, Source) Additionally, a bone cancer called osteosarcoma may happen more often in fluoridated communities, but there are conflicting results. (Source, Source, Source)

This, at least, should convince you of why I encourage making a decision based on the lesser of two evils. Is the hope of preventing one or two cavities enough to risk a higher chance of cancer?

3. Brain/Central Nervous System Effects

Concerns about the impact of fluoride on the brain began in the 1990s in the infamous Mullenix study, which found that both prenatal and postnatal exposure to the chemical led to deficits in cognition and/or attention.

In any case, it seems clear that in both animals and human beings, low levels of consistent fluoride ingestion may increase the risk for some sort of brain damage.

Various human studies, conducted by various sources including Harvard University, suggest that significant fluoridated water exposure is associated with up to a 7-point drop in IQ scores.

The two most recent pieces of research available on fluoride and IQ (in 2019 and 2020) were conducted in Canada, which has similar fluoridation levels to the United States. Until this point, very little was known about the interaction of low-level fluoridation (0.7-1.0 ppm) and IQ.

In the first study, published in August 2019, researchers discovered a 3.66-point lower IQ score in babies born to mothers exposed to fluoridated water.

A January 2020 study differentiated between breastfed and formula-fed babies, as formula typically contains a significant amount of fluoride. They found that breastfed babies had an IQ 6.2 points lower than children living in unfluoridated communities, and formula-fed children had an IQ 9.3 points lower!

For context, the average IQ of people in the US is 98. Over two-thirds of people have IQs between 85-115, whereas very few fall below 70 or above 130.

Because it might cause you to absorb more aluminum — which likely plays a role in brain degradation — fluoride may contribute to the development of Alzheimer’s disease.

A review of the available research states: “The influence of fluoride on processes of AD initiation and progression is complex and warrants further investigation, especially considering growing environmental fluoride pollution.”

A 2019 study found that the oxidative stress caused by fluoride may stop the antioxidant activity of AChE inhibitors used to treat the symptoms of Alzheimer’s disease.

We also know that fluoride may affect circadian rhythms and sleep, as well as a number of neurotransmitter levels. These impacts have not been studied but could have incredibly far-reaching effects for not only brain health but overall health.

A cross-sectional study conducted by scientists at several medical schools in New York City, released in December 2019, looked at sleep effects in adolescents exposed to fluoride.

In the 473 teenagers included in the study, they found that: “Fluoride exposure may contribute to changes in sleep cycle regulation and sleep behaviors among older adolescents in the US.” Specifically, fluoride exposure almost doubled the participants’ risk of reporting symptoms of sleep apnea.

It’s possible that increasing water fluoridation might impair auditory working memory of adolescents. The writers concluded, “The study may support the hypothesis that excess fluoride in drinking water is neurotoxic.”

Two studies (one in Mexico, the other in the United States) discovered that the more fluoride a mother ingested during pregnancy, the higher the risk for her children to develop ADHD.

A late 2019 review suggests that fluoride ingestion may also play a role in the risk of developing autism spectrum disorder. While this research doesn’t show a causal link (which means fluoride does not actually cause autism), it suggests that there is a correlation between water fluoridation and high autism rates.

One possible reason for this is the way fluorine molecules react synergistically with aluminum’s free metal cation (Al³⁺).

4. Kidney Disease

Over the past few years, the interactions between fluoride and the kidney have been made clearer.

Ingesting fluoride increased the markers of kidney injury in adults living in Mexico.

In Sri Lanka, fluoride toxicity was identified as “contributing to the molecular mechanisms” behind chronic kidney disease.

A 2018 meta-analysis of the available research on this topic found that:

“These studies reveal that there are direct adverse effects on the kidneys by excess fluoride, leading to kidney damage and dysfunction. With the exception of the pineal gland, the kidney is exposed to higher concentrations of fluoride than all other soft tissues. Therefore, exposure to higher concentrations of fluoride could contribute to kidney damage, ultimately leading to chronic kidney disease (CKD).”

5. Hypothyroidism

Almost 5% of the United States population has some form of hypothyroidism (underactive thyroid). Around the world, this condition is a major health concern.

Several significant pieces of research have found a link between fluoride exposure and hypothyroidism or related symptoms.

The reasons thyroid function may be connection with fluoride exposure are twofold:

1. Poor iodine absorption is directly associated with the development of hypothyroidism. Fluorine molecules, like iodine, are halogens on the periodic table. Other halogens (fluorine, in particular) compete with iodine receptors in the human body and may block or unseat iodine molecules from pairing with these receptors.
2. In humans, more exposure to fluoride is equivalent to higher levels of TSH (thyroid-stimulating hormone). While TSH levels rise in the progression of hypothyroidism, they also go up during system-wide inflammation, such as trauma during a hospital stay. Fluoride is also connected with inflammatory responses.

Hypothyroidism happens more frequently in fluoridated communities — in fact, its prevalence is directly linked to levels of water fluoridation.

Thyroid hormone levels are altered in children exposed to high levels of fluoride.

Symptoms of iodine deficiency, including thyroid dysfunction, and developmental disordered associated with water fluoridation, are very similar and very likely related.

One 2018 analysis came to the stark conclusion that, “The link between fluoride exposure during pregnancy at the fluoride levels present with community water fluoridation, disturbed thyroid hormones, and developmental disorders due to disturbed thyroid hormone metabolism is now sufficiently clear to warrant the immediate cessation of community water fluoridation schemes.”

A meta-analysis, also published in 2018, reviewed the evidence and found a “positive correlation between excess fluoride and hypothyroidism.” These kinds of studies are more reliable than individual studies because they look at evidence from multiple sources and compare it to draw conclusions.

6. Risk of Chronic Diseases

Fluoride might increase the risk for a number of diseases and health conditions in addition to those listed above. Those with correlations already found include:

• Bone fractures (Source, Source)
• Diabetes and related complications (Source, Source)
• Early puberty (Source)
• Anemia (Source)
• Ossification of posterior longitudinal ligament (OPLL), a spinal cord disease (Source)
• Childhood increase of cardiovascular disease risk factors (Source)

Is Fluoride in Toothpaste Bad?

This question is one I answer fairly often. In my experience, the use of over-the-counter fluoride toothpaste doesn’t seem to correlate closely with fewer cavities. However, I also work closely with my dental patients to control the underlying causes of recurrent tooth decay, such as nutritional deficiencies, mouth breathing, and the like.

According to the Cochrane Database of Systematic Reviews, an extremely reliable source for scientific reviews, fluoride toothpaste at concentrations of 1,000 ppm and higher can prevent cavities in children and adolescents.

For context, over-the-counter fluoride toothpaste for children is frequently sold in concentrations below 1,000 ppm because of concerns of dental fluorosis and toxicity of concentrated fluoride if swallowed.

Adult fluoride toothpaste is generally in the 1,000-1,500 ppm range.

However, another concern about fluoride toothpaste is the presence of other potentially abrasive or toxic ingredients often found along with fluoride. The most concerning of these are:

• Triclosan
• Sodium lauryl sulfate (SLS)
• Artificial coloring
• Titanium dioxide

In the past, I’ve recommended prescription-strength fluoride toothpaste of 5,000 ppm to certain patients. I rarely, if ever, prescribe this anymore, as the alternative of hydroxyapatite toothpaste makes it unnecessarily dangerous for most patients.

Alternatives to Fluoride Toothpaste (And When to Use Them)

Many people simply don’t need a toothpaste that remineralizes cavities.

You can do much more to reverse cavities naturally simply by adjusting your diet and following better dental hygiene, like mouth taping at night, tongue scraping, and rinsing your mouth after eating acidic or sugary foods.

For patients who do need extra support remineralizing, I now recommend a toothpaste containing hydroxyapatite particles. It is just as effective at remineralizing early tooth decay as fluoride with none of the associated dangers.

The particles in hydroxyapatite toothpastes are actually tiny, nano- or macro-sized bone fragments that your teeth can incorporate to strengthen enamel and remineralize the surface.

They’re non-toxic and not only remineralize teeth, but prevent and reverse tooth sensitivity when delivered as nano-particles.

My preferred hydroxyapatite toothpaste is RiseWell. The second is probably most effective for improving sensitivity, but the first contains a higher concentration of hydroxyapatite.

In rare cases — generally, for patients suffering from extremely painful sensitivity due to advanced periodontitis or chemotherapy treatment for cancer — I still recommend prescription fluoride toothpaste.

I definitely don’t recommend fluoridated toothpaste to children who aren’t old enough to fully control their swallowing. I draw this line around the age of eight, though I personally don’t see a need for fluoride toothpaste even after that age.

Young children may unintentionally swallow way too much toothpaste and experience serious negative side effects, from fluorosis to toxic poisoning. After all, there’s a reason that even over-the-counter toothpaste with fluoride contains a poison warning!

What is Fluoride Varnish and Who Should Use It?

Fluoride varnish is the gel-like treatment used by your dentists or dental hygienist after your teeth have been cleaned. The problem with varnishes is that they have extremely high levels of fluoride which can then be absorbed into your bloodstream and distributed throughout the body.

My suggestion? When you go to the dentist, tell them to skip this treatment altogether.

Are Fluoride Treatments at the Dentist Safe for Kids?

At the end of a child’s teeth cleaning, the dentist or hygienist will typically apply fluoride varnish, then suction any additional liquid and advise the child to avoid eating or drinking for at least 30 minutes.

Because of the concentration of fluoride in these dental treatments, eating or drinking (and even swallowing saliva) has a risk of exposing your child to higher-than-necessary amounts of the chemical.

Many dentists will use this varnish on 3- or 4- year olds, but I don’t trust that children at that age will avoid swallowing it. That’s why I used to tell parents to wait until their child is 8-10 years old before allowing this post-cleaning treatment.

Now, I recommend nano-hydroxyapatite toothpaste for children who need to remineralize cavities—there’s no danger of swallowing, so even younger children can use it safely.

Various manufacturers are working on a similar varnish made with hydroxyapatite to temper any toxic effects that may occur due to fluoride. You should expect to see these used by functional dentists in the next few years.

Do Babies and Toddlers Need Fluoride Water?

I don’t ever think that babies or toddlers need exposure to fluoridated water. Because their little bones are still growing, the fluoride from the water will be incorporated into bones and throughout the rest of the body, where it can cause numerous problems. These kids are also at a higher risk of dental fluorosis, which can be permanent.

Instead, focus on the right foods for your child and avoid baby bottle tooth decay by not bottle-feeding your child as they fall asleep, especially with a formula that contains decay-promoting ingredients, such as high fructose corn syrup.

Don’t I Need Fluoride to Prevent Tooth Decay?

The reason babies and toddlers don’t need fluoridated water is the same reason that teenagers, adults, and even the elderly don’t need fluoridated water: It’s not the key to preventing or reversing tooth decay.

Cavities and oral disease occur because of a lack of proper hygiene and diet as well as mouth breathing and some genetic components. Many families don’t need any sort of remineralizing toothpaste, so I advise those who do on a case-by-case basis.

Families that primarily eat meats, vegetables, and fruits, and drink plenty of water instead of fruit juice and sodas, rarely have cavities. They have very low bacterial activity because they’re eating foods that heal cavities naturally and prevent tooth decay.

(Which also means, of course, that they’re avoiding the foods that directly cause tooth decay.)

How to Get Fluoride Out of Your Life

It’s virtually impossible to avoid all fluoride, but you can go a long way in reducing your exposure or detox the amount that you’ve already bioaccumulated.

First, try focusing on a more alkaline diet — the more acidic your urine, the less fluoride you naturally excrete. (You might also benefit from drinking tamarind tea, increasing the amount of high-selenium foods you eat, and exercising regularly. All of these activities will cause your body to excrete more fluoride.

Other ways to greatly decrease your fluoride consumption include:

Using a Hydroxyapatite Toothpaste — Switching from a fluoride paste to a hydroxyapatite option, like RiseWell, is a great first step.

Filtering Your Water — Filters including ZeroWater, reverse osmosis, deionizers, and activated alumina will reduce the amount of fluoride in your tap water. Be aware of exactly the type of filter you’re using: activated carbon filters or other common types likely don’t get rid of this particular toxin.

Drinking Distilled Water — There are important minerals in water that are removed by distillation, but you can drink distilled water to avoid fluoride. If you’re getting minerals through vegetables, bottled mineral water, or supplements, distilled water is a great option. I generally recommend water with a pH of 7 or higher for cavity prevention. If you’re worried about missing out on important nutrients, add a few drops of trace minerals to your filtered water each day (I do!).

Using Bottled Water — The FDA requires that bottled water with fluoride must be labeled that way. Most brands don’t contain any at all.

Eliminating Processed Foods — Many processed, boxed foods have more fluoride than you might expect because they’re made using water that’s been fluoridated. Getting rid of as many processed foods as you can will carry the double whammy of both reducing fluoride consumption and supporting a healthier oral environment.

Buying Organic — Because of the fluoride-based pesticides used on many non-organic vegetables, organic options will often have less of the chemical.

Final Thoughts on Fluoride

I know it might be surprising for a dentist to say, but I stick to my guns here: People just don’t need fluoride.

While I used to recommend it to certain patients, the development of hydroxyapatite toothpaste has completely eliminated the need for even prescription-strength toothpastes and varnishes.

This toxin was introduced into public water supplies throughout the second half of the 20th century and is currently present in almost 75 percent of public water in the US. However, there is little to no research supporting its purported ability to prevent cavities when ingested.

Additionally, consuming fluoride via tap water and other sources leads to many dangers, including fluorosis, cancer, brain/central nervous system damage, and various disease risks.

Ultimately, we’ve missed the real discussion of the root cause of cavities when we put the focus on using fluoride. To truly prevent and reverse cavities, the best practices you can follow are:

1. Prevent dry mouth. Try mouth taping at night to help you stop mouth breathing, and and have a conversation with your physician about any medications that could be causing dry mouth.
2. Eat a diet rich in plants, grass-fed proteins, grass-fed dairy, nuts, seeds, and healthy fats. When you “cheat” with something high in acid, refined carbohydrates, or sugar, spend only a brief time consuming it, rinse your mouth, then brush 30-45 minutes later to neutralize the impact of it to your teeth.
3. Incorporate good dental hygiene, such as brushing teeth the right way, tongue scraping, flossing, and getting regular cleanings at the dentist.
4. Remember that genetics and epigenetics (the changeable “on-off switch” of your DNA) play a part in dental health. Research shows that epigenetics can be positively influenced by healthy dietary and lifestyle habits—a benefit you can experience not only for yourself, but that you can even pass to your offspring.

That’s what we’re all about here at AsktheDentist.com: not only having the right conversations about dental and oral health, but sometimes changing the conversation.

Learn More: Fluoride and IQ: Does prenatal exposure to fluoride lower IQ?