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There are two sides to any story, and that is definitely true in the case of fluoride. Since being introduced into the public water supplies of much of the U.S. (and several other countries) in the 1960s, a consistent debate has existed on whether or not fluoride is truly safe as a water additive or dental health product.
It’s more complex than you might believe at first. On the one side, many public health organizations hail fluoride as a near-miracle for dental health and insist there are no questions or contrary pieces of evidence whatsoever.
For example, the Centers of Disease Control and Prevention (CDC) states, “Because of its contribution to the large decline in cavities in the United States since the 1960s, CDC named community water fluoridation one of 10 great public health achievements of the 20th century.” The American Dental Association and American Academy of Pediatrics agree and have since the beginning of public water fluoridation in the mid 1900s.
Unfortunately, the answer isn’t that simple.
The controversy over fluoride in water has been the main point of contention for anti-fluoridationists for the last several decades, since it was introduced widely in 1960.
A growing body of research has existed since before fluoride was ever approved for dental use finding it has the ability to cause long-lasting negative health effects in various bodily systems.
“Fluoride” refers to any compound containing a fluorine ion. Sporting a chemical symbol of “F” and an atomic number of 9, fluorine is one of the well-recognized elements on the periodic table.
As a pure gas, fluorine is “the most reactive and electronegative of all the elements.” It has extremely damaging effects to any living organism with which it comes into contact.
In nature, calcium fluoride (CaF2) is found in soil and water. Spring water in areas without industries that regularly use fluoride generally contains about 0.01–0.03 ppm (parts per million, also known as milligrams per liter or mg/L) of calcium fluoride naturally, while seawater is closer to 1.3 ppm.
These amounts vary greatly depending on location — in some parts of the world, calcium fluoride is found up to 10–20 ppm in water supplies, which is universally recognized as an unsafe ingestible amount of the compound.
Despite the insistence of various organizations to tell the public that this same compound is what’s added to their drinking water, this isn’t actually true. Calcium fluoride is not well-absorbed into the body, whereas sodium fluoride (NaF) is. This chemical compound does not occur in nature and was generally considered industrial toxic waste until 1950, when it was announced as a new dental health initiative.
1945 marked the start of studies in several cities across the U.S. to compare the prevalence of cavities (dental caries) between children and adults drinking fluoridated or unfluoridated water. According to the CDC, dental caries were reduced 50 percent to 70 percent in fluoridated communities during the 13–15 years of these “studies.”
However, no data is available for the amount of cavity reduction experienced by the “control” communities in these experiments. As dental health has improved steadily in both fluoridated and unfluoridated communities of the U.S., this data would be very worthwhile but, unfortunately, does not exist or is not readily available to the public.
As of 2020, about 72.7 percent of people in the U.S. with community water systems were provided with fluoridated water. This is a drop from 2014, when it was at 74.4 percent, resulting partly from community efforts of citizens urging their leaders to remove fluoride from public drinking water.
Unlike what you may expect, though, the fluoride used in your drinking water is not calcium fluoride nor sodium fluoride. Now, in 90 percent of our fluoridated water, it’s a compound known as hydrofluorosilicic acid (HFS or FSA). HFS is a by-product of the process used to create phosphate fertilizers that used to be considered toxic waste and is now (more than likely) an additive in your family’s water.
In a petition submitted in 2013 by a former Environmental Protection Agency (EPA) scientist, J. William Hirzy, Ph.D., and colleagues requested the EPA discontinue the use of HFS in public water due to the proven adverse effects it may have on human health, including issues via the presence of arsenic.
That’s correct: The additive used to improve your dental health also contains arsenic, which, incidentally, is allowed in measures of 0.010 ppm in water by EPA standards, although the maximum contaminant level goal is zero, due to arsenic’s cancer-causing impact.
Not only does hydrofluorosilicic acid contain arsenic, but it also leaches lead from piping at much greater rates than sodium fluoride, although both compounds have this effect. Lead crosses the blood-brain barrier — as well as to unborn children in pregnant mothers — and has no known safe level of contamination that is free of harmful effects, such as potentially causing cancer.
According to the CDC and other governmental bodies, there is only one known cosmetic issue that occurs from too much fluoride in water or from other sources: fluorosis.
The CDC also provides a toxicology guide for fluorines, fluoride and hydrogen fluoride. This guide sets a “minimal risk level” of fluoride at 0.05 mg/kg/day for chronic exposure, which defines the amount of fluoride that would cause issues when chronically ingested. That figure can be translated to 0.11 milligrams per pound of weight per day.
Doing the math: This means that a 160-pound person drinking an optimal amount of water (80 ounces) from a fluoridated source would ingest 1.66 milligrams of fluoride from that water alone. The CDC’s given “minimal risk level” of 0.11 mg/lb/day (0.05 mg/kg/day) means that same person should not consistently consume 3.65 milligrams of fluoride each day or may suffer adverse effects.
Not only is that a close margin, but this metric doesn’t consider the additional fluoride from toothpaste, mouthwash, food and drinks that the same person may also regularly ingest. It also is considering a full-grown adult who understands how to not swallow toothpaste, which can’t always be said for a small child brushing her teeth with fluoridated toothpaste with 1,000 times the fluoride as tap water per volume.
The adverse effects should just be that one “cosmetic” problem, though, right? Not quite — the CDC finally included a prevalence of “increased bone fractures in the elderly” related to drinking fluoridated water after it could no longer avoid the evidence. This is not listed on the community fluoridation material the CDC distributes.
A growing number of professionals have doubted the safety of water fluoridation in its current state for many decades. This problem exists, in part, because the amount of long-term, high-quality, unbiased research available is limited to nonexistent.
For example, the NHS Centre for Reviews and Dissemination (a British governmental body) looked at the evidence about the carcinogenic potential of fluoride. The results were tentative at best, and the organization stated at the end of its compilation that, “Given the level of interest surrounding the issue of public water fluoridation, it is surprising to find that little high quality research has been undertaken.”
In 2006, the National Research Council conducted a review entitled “Fluoride in Drinking Water: A Scientific Review of EPA’s Standards.” The research led the authors to a few conclusions about the safety of fluoride according to available data at that time, such as:
Another expert who spoke out about concerns of the safety of fluoride is John Colquhoun, a dentist in New Zealand who was appointed to Principal Dental Officer of Auckland, New Zealand’s largest city. Dr. Colquhoun, once passionately pro-fluoridation, re-examined the facts and studies available on fluoridation and wrote an explanation of his staunchly anti-fluoridation stance in Perspectives in Biology and Medicine in 1997.
He explains that this dedication to fluoride as the savior of dental health, particularly for low-income families who do not receive regular dental care, is based, in his opinion, on a determination to “bend over backwards to explain away new evidence,” specifically evidence opposing the common view. Colquhoun alleges that flawed studies contributed to this issue greatly, but when he was presented with the evidence of the decline of tooth decay in totally non-fluoridated communities, his conclusion was that fluoride actually does far more harm (to the teeth and other parts of the body) than it ever does good.
As with most things, this view is opposed by many. Herschel S. Horowitz, DDS, MPH, a former chief of the Community Programs Section of the National Institute of Dental Research, wrote a rebuttal to Colquhoun’s letter. He concluded that the letter contained poor references to junk science and remains convinced that community water fluoridation is totally safe.
What does fluoride do once it enters the body?
When ingested, fluoride passes the blood-brain barrier, meant to protect the brain and nervous system from damage of foreign invaders, and can pass through placenta into the body of an unborn baby.
Fluoride bioaccumulates, meaning that not all of it is metabolized and/or excreted by your body’s natural waste disposal. About 50 percent of the fluoride you ingest through water or other food sources is excreted by urine, while the other half tends to accumulate in the calcified areas of the body, such as bones and teeth. Alkaline urine better removes fluoride from the body than acidic urine.
In addition to bones and teeth, fluoride builds up in the pineal gland, a hormone gland responsible for the secretion of melatonin to manage circadian rhythms and sleep patterns. A study to determine the concentration of fluoride in the pineal gland discovered that, by the time the adults in the study died in old age, the calcium-to-fluoride ratio of that gland was actually higher than in bone. This suggests fluoride plays a part in the calcification of this gland, which would lead to poor melatonin production over time.
Because it leaches lead from water pipes, fluoride has been suspected to lead to higher levels of lead in the bloodstream. Research from Dartmouth University, published in Neurotoxicology, confirmed this theory in 2000, finding significantly higher lead levels in children exposed to water fluoridated by HFS.
The scientists said this rendered the hypothesis “null” that there is no difference between sodium fluoride and HFS and that this could lead to concerning levels of lead, particularly in children with additional risk factors, like those who live in older homes.
Since it passes the blood-brain barrier, some research has also focused on the impact of fluoride accumulation in the brain.
Scientists in India conducted an animal study in 2014 on these effects (using sodium fluoride, not HFS) and found that: “Increase in the NaF concentration resulted in increased fluoride deposition in brain tissue. This increased fluoride content led to increased levels of certain neurotransmitters such as epinephrine, histamine, serotonin and glutamate and decreased levels of norepinephrine, acetylcholine and dopamine in a dose-dependent manner.”
Another interesting fact you may want to be aware of is that rats, like those in the above study, are not as sensitive to fluoride absorption as humans. They must be given significantly higher amounts of the chemical to reach the comparative level of fluoride in their blood (plasma) as a typical person drinking fluoridated water and ingesting other sources of fluoride.
Fluoride also inhibits various enzymes throughout the body responsible for normal processes of your metabolic energy systems.
Fluoride is a part of the process by which teeth demineralize and remineralize each day. When you eat and drink certain foods, the mineral on your teeth is stripped by small amounts, and using fluoride topically helps remineralize and calcify teeth, making them stronger and less susceptible to dental caries (cavities).
Because many families rely on tap water for the most cost-effective method of water intake, fluoride was introduced to public water supplies to prevent cavities in children who may not have good access to regular dental care. According to research from various sources, fluoridation does decrease the incidence of dental caries and the number of teeth affected by these issues, although many of these studies are defined as “low” or “moderate” quality at best when reviewed.
The role of fluoride in dental health was discovered, somewhat by accident, by a dentist named Frederick McKay. McKay documented reports of what was called “Colorado Brown Stain,” a discoloration on the teeth seen in children who grew up in Colorado Springs, Colo., and also noted that teeth with this discoloration were more resistant to decay.
Subsequent analysis of similar findings led to the realization that water naturally high in fluoride had a teeth-strengthening effect, although it may also result in mottled teeth.
Now known as “dental fluorosis,” this condition is prevalent mostly among children under the age of 8 who are not completely rid of their baby teeth. Understood to be mostly a cosmetic problem, fluorosis does not always result in mottled adult teeth (although it can and is irreversible).
Crippling skeletal fluorosis is a more serious form of this problem that occurs mostly in third-world countries with extremely high levels of naturally occurring fluoride in water, marked by rigidity of bones and increasing inability to complete a full range of motion.
Many people consider dental fluorosis to be a problem that may only result in a bit of embarrassment or social anxiety. However, it may be an outward symptom of a much more systemic problem.
Dental fluorosis has continued to affect a great deal of the U.S. population, and rates continue to rise, according to CDC statistics. This is most likely due to the vast number of fluoride sources now available to the public.
When comparing communities with and without fluoridated water, there does seem to be a trend in some areas for fluoridated communities to have less cavities. However, this gap is closing rapidly.
Interestingly, though, the ingestion of fluoride may just not be the answer for healthy teeth. Countries widely using fluoridated water in public systems have seen a decline in cavities, yes, but that trend is almost identically matched in similar countries that have never practiced public water fluoridation.
Dr. Arvid Carlsson of Sweden, a Nobel Prize winner, stated publicly that it’s possible and even probable that fluoride can benefit teeth when applied topically, but it is “against modern pharmacology” to think there’s anything beneficial about ingesting the substance, particularly because the disparity in how much a single person consumes is so vast.
The CDC conducted a study between 1986–1987 of dental caries in children across a number of cities in the U.S. Researchers found, most fascinatingly, that fluoridated communities did, indeed, have a lower number of cavities per child than unfluoridated communities — but barely: 2 versus 2.1, when comparing internal quality of teeth (the supposed reason fluoride must be ingested).
The U.K. Department of Health still concludes, however, that the fluoridation of water, milk and salt (the latter two are not fluoridated in the U.S.) is the best and safest way to prevent dental caries.
Many experts have been concerned about the bioaccumulation of fluoride due to the overwhelming availability of fluoride in dental products, food, drinks and water, including a group of EPA union members who have urged the EPA to change its stance on water fluoridation and a group of almost 5,000 medical professionals across several countries who signed the Fluoride Action Network’s petition to end water fluoridation.
Because of the dangers of fluoride toxicity, the U.S. Food and Drug Administration (FDA) began requiring a warning on all fluoride toothpastes manufactured after April 1997 to contact the nearest poison control center if the toothpaste is ingested because this “drug” may cause adverse effects. Remember, toothpaste contains somewhere around 1,000 times more fluoride per volume than fluoridated water.
As mentioned earlier, one concern held by certain people is the hazards of using silicofluorides to fluoridate water, rather than sodium fluoride, the substance that has been used in virtually all fluoride safety research. The petition listed above to remove silicofluorides from drinking water points out that fluoridated water using HSF contains 100 times more arsenic than fluoridated water using sodium fluoride at 0.7 ppm.
Whatever the source, the ingestion of large amounts of fluoride is not good for you. While it may offer certain teeth-strengthening benefits when used topically, the benefits should be weighed against the long-term costs.
Fluoride isn’t just in toothpaste and tap water. If you’re trying to avoid fluoride, you should be aware that it may be found in the following, both naturally and unnaturally:
Many people trying to reduce their fluoride intake opt for bottled water, which does come with its own set of concerns but generally does not contain fluoride. The FDA requires bottled water containing fluoride to be labeled as such.
One major cause of concern when ingesting fluoride is the potential it may have to negatively affect the central nervous system (CNS). A famed study by Dr. Phyllis Mullenix was one of the first occasions on which this CNS effect was quantified. In fact, you couldn’t discover any arguments on the pros and cons of fluoridation that failed to include Mullenix’s discovery.
This well-designed study, using the latest technology available at the time, was conducted in the mid-1990s on rats. Emphasis on the study came from reports from China that high levels of fluoride in drinking water (multiples of any current levels in the U.S.) had been found to affect the CNS preceding skeletal fluorosis. The animals were given varying levels of fluoride at multiple stages of development and compared with controls.
Mullenix discovered that fluoride treatment during fetal, weanling and adult development all had pronounced behavioral effects, even when the plasma (blood) levels of fluoride did not seem to be all that elevated. Prenatal exposures seemed to result in hyperactivity symptoms, whereas weanling/adult exposures both resulted in “cognitive deficits.”
Another brain-related danger of fluoride is the potential that it may result in lower IQ. Studies have found varying degrees of IQ disparity, from a 2.5-point drop to a 7-point difference in children exposed to fluoridated water versus those who are not.
The meta-analysis that reflected a 7-point change in IQ was conducted by researchers at the Harvard School of Public Health. Although the results were highly suggestive, the scientists were quick to state that the studies they examined were not conclusive enough to draw any sort of cause-and-effect relationship and, in some cases, reflected fluoride levels in water far above what anyone in the U.S. is generally exposed to.
However, researchers were intrigued enough by their results to begin a pilot study in China to garner more information. This is the first of what is said to be many follow-up studies regarding fluoride and intelligence. In the 51 human study participants, it was found that moderate-to-severe dental fluorosis was correlated with poorer scores on two types of intelligence tests.
Some are also concerned that the combination of aluminum and fluoride exposure might be a contributing factor to the development of Alzheimer’s disease. In animal studies, rats given sodium fluoride (NaF) had significantly higher tissue aluminum levels and “alterations of cerebrovascular and neuronal integrity.”
As there is a large amount of evidence to suggest that aluminum plays a role in the development of Alzheimer’s, it’s an avenue worth looking into deeper.
Since fluoride crosses the blood-brain barrier, there are many effects it could have that are currently unknown. However, we do know, according to studies listed above, that fluoride might disrupt circadian rhythms and does alter the levels of certain neurotransmitters that are vital to healthy brain chemistry.
Another hotly debated potential risk of fluoride is its potential to influence the risk of certain cancers.
A 1977 study comparing the 10 largest fluoridated and unfluoridated cities at that time found an increase in cancer-related deaths of 18 percent in the fluoridated cities compared to those that weren’t, equating to about 3,000 more cancer deaths per 10 million persons in 1969, the studied year.
A similar study, published earlier in 1977, detailed a review of cancer death rates over 17 years, between 1952–1969. No difference in the rates was discovered in persons up to 44 years of age between fluoridated and unfluoridated communities. In those between 45–64 years of age, an additional 1,500 cancer deaths per 10 million people were recorded in fluoridated cities, and the number rose to 3,500 more cancer deaths per 10 million people when observing those over 65.
One review of cancer instances between 1978–1992 found that: “Cancers of the oral cavity and pharynx, colon and rectum, hepato-biliary and urinary organs were positively associated with FD [fluoridated drinking water]. This was also the case for bone cancers in male, in line with results of rat experiments. Brain tumors and T-cell system Hodgkin’s disease, Non-Hodgkin lymphoma, multiple myeloma, melanoma of the skin and monocytic leukaemia were also correlated with FD.”
In that study, four types of cancers were actually correlated with a decreased risk in persons exposed to fluoridated water.
Of particular interest in the fluoride debate is the instances of osteosarcoma, a rare form of bone cancer. A relatively small study was published in 1993 finding a 6.9 times increased risk of osteosarcoma among males under 20 years of age in the most fluoridated parts of a three-county area. (69)
The Harvard School of Dental Medicine also conducted a study about this risk and found similar results of an increased risk for young males of osteosarcoma when drinking fluoridated water.
However, other follow-up studies have found no link or at least no significant increase in osteosarcoma cases between fluoridated and unfluoridated communities.
Unlike what was originally assumed, it seems the ingestion of fluoride does not have a positive impact on bone health — and may actually have a pronounced negative effect.
A study conducted in Mexico found an increase in bone fractures and major tooth damage in children exposed to fluoridated water.
Some research has found an increase in hip fracture risk among the elderly when consistently drinking water fluoridated at 1 ppm. However, other sources found no link between fluoridation and bone fractures.
It’s true that the rate of hip fractures related to osteoporosis has increased in the elderly over the same period of time as the dawn of water fluoridation, but there is not yet evidence to suggest this could be attributed to fluoride, as the causative factors behind such a disease are vast and not usually just one toxin or risk factor.
It appears it could be among the risk factors, however.
Possibly related to the association between fluoride and hormonal function is the evidence that fluoride may be linked to hypothyroidism. In a study comparing fluoridated and unfluoridated areas of the U.K., researchers discovered that those living in unfluoridated areas were almost two times less likely to develop hypothyroidism.
Remember that fluoride has been found to collect in the pineal gland? This may have further-reaching effects than just the interference with circadian rhythms. A 1997 study using gerbils discovered that fluoride was associated with faster sexual development in the females in the study.
It could be a very important point, as early puberty may possibly lead to issues ranging from short stature to an increased risk of breast cancer.
In addition, fluoride exposure could potentially delay puberty in boys. One study conducted in Mexico ultimately relayed that “Childhood fluoride exposure, at the levels observed in our study, was associated with later pubertal development among Mexican boys at age 10–17 years. Further research is needed to confirm these findings.”
With diabetes diagnoses are at an all time high, a great deal of research is focused on the ways we can reduce the impact of this reversible condition. A literature review of the connection between fluoride and diabetes, conducted by Dr. Geoff Pain, an Australian chemistry specialist, left the scientist in no doubt of the results.
Pain stated: “There is strong evidence that fluoride causes diabetes … Diabetics are a ‘sensitive subpopulation’ or ‘vulnerable group’ and no attempt has been made by Australian health authorities to warn diabetics about fluoride toxicity or protect them from harmful exposure.”
However, this review does not equate to convincing proof that diabetes is caused by fluoride exposure. While it warrants further investigation, another study found that low levels of fluoride, like those found in water in the U.S., actually helps improve insulin resistance and aids in glucose homeostasis.
The best way to protect yourself begins with staying informed. For instance, do you know if your community fluoridates its water?
The CDC offers a searchable map to find out whether or not your local public water is fluoridated and at what rate.
Once you know you’re being exposed to fluoride in tap water, and at what rate, what measures can you take to detox your body?
An alkaline diet, designed to balance the internal pH of your body, is one of your best lines of defense in fluoride detoxification. While you excrete 50 percent, on average, of the fluoride you ingest, you can drive that percentage up by maintaining an alkaline environment. Alkaline diets rely a lot on plant proteins and raw fruits and vegetables to help the body rid itself of harmful substances.
Research has found that the popular Indian beverage tamarind tea can help your body detox fluoride from your system. It’s not the easiest tea to find but might be worth ordering online if you’re concerned about your fluoride exposure.
A rat study suggests selenium supplementation can help reduce or reverse the effects of fluoride on the brain. This does not necessarily mean this impact extends to human, but foods high in selenium are also good for your thyroid, heart and may reduce your risk of cancer, so incorporating those foods definitely isn’t going to hurt.
That’s right, one of the benefits of exercise may be fluoride detox. A 2013 study in Argentina discovered plasma fluoride levels decreased in rats exposed to moderate exercise versus those that did not exercise. The rats also had reduced insulin resistance, leading the researchers to suggest daily physical exercise may help avoid the negative effects of fluoride on glucose metabolism.
In addition to detoxifying my system of fluoride, it’s also important to reduce future exposure. There are some methods you can use to protect yourself and your family from excess fluoride.
Many pesticides used on food crops are fluoride-based, such as cryolite. Buying certified organic foods means you aren’t exposing yourself to these pesticides.
In addition, the more processed a food is, the more fluoride it’s likely to contain, because industrial food-making involves using fluoridated water. You can also reference the U.S. Department of Agriculture National Fluoride Database to verify what foods you’re eating that tend to contain significant amounts of fluoride.
Fluoride has been found to transfer to infants via breast milk. (88) To make sure you’re protecting your child from early fluoride exposure, extra precaution should be taken during this sensitive time to avoid fluoride.
Unlike what you might expect, not all water filtration systems work to reduce or eliminate fluoride. However, there are three types you can utilize in your home that will filter out fluoride: reverse osmosis, deionizers (using ion-exchange resins) and activated alumina. Activated carbon filters, like the typical brands you might see advertised for the home, do not filter fluoride.
One thing to remember when filtering water is that some methods, like steam distillation, might remove fluoride but also remove much of what makes water so beneficial to your health.
Especially if you have youngsters in the home who may be apt to swallowing toothpaste, you can protect them from fluoride exposure by using unfluoridated dental products instead of the now-popular fluoride options. Although there may be some dental benefits to the topical use of fluoride in these products, it may be your preference to avoid it altogether.
It is unfortunate to see the dangers that both tap and bottled water pose, but various people are trying to do something to correct this problem. For example, many communities can take advantage of a water delivery service — just be sure to double-check the water has been filtered to remove fluoride.
Another option for some people is the much newer option of boxed water, which doesn’t present many of the risks of bottled water and is also absent fluoride.
I mentioned earlier that the number of fluoridated communities actually decreased in the U.S. in recent years, largely due to people taking action to tell their local leaders they no longer wanted to fluoridate their community water. Communities around the globe are taking this action.
As you become more informed, don’t be afraid to use your voice to let your leaders know the dangers of fluoridation.
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