Can Fluoride be absorbed into the blood from within the mouth without swallowing?

Can Fluoride be absorbed into the blood from within the mouth without swallowing?

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I'm having a discussion with somebody regarding Fluoride usage. I told him that even if he doesn't like the idea of ingesting it, brushing and spitting it out will do you no harm. He then said this:

You have missed the point of ingestion massively! Brushing with fluoridated paste is NOT fine.

The mouth, with its gum entry and under tongue glands are the PERFECT entry point to the blood, without even swallowing? What do you think oil pulling is all about? Fluoride passes those barriers as easy as the shit that resides in your blood can!"

Now I call BS on this, but I'd just like an expert opinion with cited sources if possible. Can Fluoride be absorbed purely by the mouth without ingestion?

Although I'm having a hard time finding a source that provides specific information on fluoride in toothpaste, this review explains that fluoride is most readily absorbed through intestinal epithelia and that fluoride absorption through other tissues, such as oral epithelia, depends strongly on other chemical properties of fluoride-containing compounds: their

"reactivity and structure, solubility, and ability to release fluoride ions."

This suggests that you would need additional information concerning the overall toothpaste formula.

This review shows the rates at which fluoride ions are released from various toothpaste formulations. Figures 2 and 3 show that the highest discharge rate is roughly 1.7ppm and the lowest was just under 0.5ppm, both occurring after a 24hr period. The authors note in the discussion that these measurements are likely higher than what would occur in the mouth, since they had to use deionized water for their experiments, in which fluoride is more soluble than in saliva.

Wikipedia lists fluoride toxicity levels as being between 0.5 and 1.0mg/L. Fluoride's molar mass is 18.9984 g/mol and this calculator shows that 0.5mg/L of fluoride translates to about 0.5ppm. While at first this makes the above results sound a dire, it's important to note that toothpaste remains on your teeth for far less than 24hrs and to remember that less fluoride is released into saliva than into deionized water.

Wish I could find better results on how much fluoride might be released during a typical toothbrushing session, but I'm inferring from the linked review that it would be small enough to not merit a health concern.

I emailed a dentist friend for more info and will update this post as I hear back from him.

As for the comment about glands, it's important to understand that the glands found in the mouth are secretory glands, which means that they are optimized for discharging fluids and not for accepting them.


My dentist friend wrote back, confirming that no significant fluoride absorption occurs through the gums. From him:

the only significant absorption would be through swallowing fluoride. Any that was just in the mouth would not be well absorbed… that is why we do the high dose swish and spit treatments is to avoid fluorosis but deliver sufficient fluoride to the teeth.

In short, it looks like the answer to your question is: no, fluoride is not significantly absorbed into the blood from within the mouth without swallowing.

Sorry I'm a lil late at finding this but thought I'd share two studies I found proving 'absorption of fluoride through the oral mucosa of rats'

*the second link is a study on radioactive fluoride.

Health Effects of Ingested Fluoride (1993)

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INTAKE, litE:TABOLISM, AND DISPOSITION OF HORDE FLUORIDE INTAKE The literature contains several reviews of the sources and amounts of fluoride intake by age, water fluoride concentration, and geographic region in the United States that may be consulted for detailed discussions (McClure, 1943 Parkas and Parkas, 1974 Myers, 1978 Ophaug et al., 19SOa,b, 19X5 Whitford, 1989 Burt, 1992

. This discussion will sum- marize our current understanding of the main points covered in those reports. The major sources of fluoride intake are water, beverages, food, and fluoride-containing dental products. Fluoride exposure from the atmo- sphere generally accounts for a small fraction (about 0.01 mg per day) of the intake of fluoride (Hodge and Smith, 1977

. The fluoride con- centrations in groundwater range from less than 0.

mg/L to more than 100 mg/L and depend mainly on the concentration and solubility of fluoride compounds in the soil. The fluoride concentrations in foods also depend on the fluoride concentrations in soil but can be increased or decreased according to the fluoride concentrations in water used for preparation. The fluoride concentrations in most dental products avail- able in the United States range from 230 ppm (0.05% sodium fluoride mouth rinse) to over 12,000 ppm (

.23% acidulated phosphate fluoride gel). 125

126 Health Effects of Ingested Fluoride The average intake of dietary fluoride by young children who drink water containing fluoride at 0.7-

.2 mg/L is approximately 0.5 mg per day or 0.04-0.07 mg/kg of body weight per day, although substantial variation occurs among individuals (McClure, 1943 Ophaug et al., 198Oa,b, 1985

. The classical epidemiological studies done in the 1930s and 1940s on the relation between water fluoride concentrations and dental caries and dental fluorosis determined that 0.7-

.2 mg/L was optimal because it provided a high degree of protection against dental caries and a low prevalence of milder forms of dental fluorosis. Thus, Me associated amount of intake by children (0.04-0.07 mg/kg per day) has generally been accepted as optimal, or as Burt (1992) has said, as "a useful upper limit for fluoride intake by children." Fluoride intake by nursing infants depends mainly on whether breast milk or formula is fed. Human breast milk contains only a trace of fluoride (about 0.5 ,umol/L, depending on fluoride intake) and provides less than 0.01 mg of fluoride per day (Ekstrand et al., 19X41. Ready-to- feed formulas generally contain fluoride at less than 004 mg/L (Johnson and Bawden, 1987 McKnight-Hanes et al., 1988), and formulas reconsti- tuted with fluoridated water (0.7-

) contain fluoride at 0.7 mg/L or more. Thus, fluoride intake from formula might range from less than 0.4 to over I.0 mg per day. It is evident that that range includes amounts that exceed the optimal range of 0.7-

.2 mg/L and, therefore, might be thought to increase the risk of dental fluorosis. Recent evi- dence, however, indicates that the transitional or early-maturation stage of enamel development is when the tissue is most susceptible to fluoride- induced changes (Evans, 1989 Pendrys and Stamm, 1990 Evans and Stamm, 1991a). The early-maturation stage occurs during the third or fourth year of life for the permanent anterior teeth when the amount of dietary fluoride intake in a community with fluoridated water is generally within 0.04

.07 mg/kg per day. Ophaug et al. (19XOa,b) determined dietary fluoride intake by young children in four regions of the United States. Mean intake by 6-month- old infants was 0.21-0.54 mg per day, and that by 2-year-old children was 0.32-0.61 mg per day. The mean intake by the 2-year-old children (but not the 6-month-old group) was directly related to the fluoride concentration in the drinking water. Those data are in close agreement with the findings of Dabeka et al. (1982) and Featherstone and Shields (1988

. Dietary fluoride intake by adults living in areas served with water fluoridated at about i.0 mg/L has been estimated at I.2 mg per day

Intake, Metabolism, arid Disposition of Fluoride 127 (Singer et al., 1980), I.8 mg per day Waves, 1983), and 2.2 mg per day (San Filippo and Battistone, 1971

. Intake by some people, such as outdoor laborers in warm climates or those with high urine output dis- orders (Klein, 1975), would be substantially higher. Fluoride-containing dental products intended for topical application of fluoride to teeth (especially toothpastes because of their widespread use) are an important source of ingested fluoride for both children and adults. Dowell (1981) reported that nearly 50% of his sample had started brush- ing by the age of 12 months. At 18 months, 75% were brushing with fluoride toothpaste. The average amount of toothpaste used in one brushing is I.0 g (ranging from 0.! to 2.0 g), which, for a product at 1,000 ppm, contains

.0 mg of fluoride. The results from several studies indicate that an average of 25% (ranging from 10% to 100%) of fluoride introduced into the mouth with toothpaste or mouth rinse is ingested, but the percentage is higher for young children who do not have good control of the swallowing reflex (HelIstrom,

969 Hargreaves et al., 1972 Parkins, 1972 Barnhart et al., 1974 Baxter, 1980 Dowell, 1981 Wei and Kanellis, 1983 Bell et al., 198S Bruun and ThyIstrup, 1988

. It has been calculated that the amount of fluoride ingested with toothpaste (or mouth rinse) by children who live in a community with optimally fluoridated water, who have good control of swallowing, and who brush (or rinse) twice a day is approximately equal to the daily intake of fluoride with food, water, and beverages (Whitford et al., 1987

. In the case of younger children or those who, for any other reason, have poor control of swallowing, the daily intake of fluo- ride from dental products couIc] exceed dietary intake. For several reasons, differences in fluoride intake in communities with different water fluoride concentrations are likely to be smaller today than in the 1940s, when the epidemiological studies of dental caries and fluorosis studies by H.T. Dean ant! his associates were done. The use of fluoride-containing dental products, especially toothpastes, is wicle- spread, and dietary fluoride supplements are prescribed for children from birth to teenage years more frequently in areas without water fluorida- tion. The dosage schedule for fluoride supplementation currently recom- mended by the American Dental Association and the American Academy of Pediatrics is shown in Table X-

. Furthermore, most urban areas in many states have controlled water fluoride concentrations (about I.0 mug/. In general, the so-called "halo effect" occurs in those areas where foods and beverages are processes! and packaged for distribution

128 Health Elects of Ingested Fluoride TABLE 8-1 Dietary Fluoride Supplementation Schedule Recommended by the American Dental Association and the American Academy of Pediatrics Age Group, yr Drinking-Water Fluoride Concentration, mg/L <0.3 0.3-0.7 o >0.7 Recommended amounts from birth to 2 Recommended amount from 2 to 3 Recommended amount from 3 to 13 0.25 0.50 1.0 o o o aValues are given in milligrams of fluoride per day (2.2 mg of NaF and 1.0 mg of fluoride). to other communities, including those without fluoridated water supplies. At the expense of tap-water consumption, soft-cirink consumption in the United States and Canada has increased sharply in recent years in both fluoridated and nonfluoridated areas (Bears et al., 19XI Chao et al., 1984 Ismai! et al., 1984 Clovis and Hargreaves, 19X8

. Fluoride intake from soft drinks and other beverages prepared with fluoridated water amounts to 0.3-0.5 mg per 12 ounces, which makes such products quantitatively important sources of fluoride. Those considerations and others, such as use of certain home-water purification systems that might remove fluoride and consumption of bottled water that might have fluoride concentrations above or below the optimal range, lead to the conclusion that reasonably accurate estimates of total daily fluoride intake are no longer as simple and straightforward as they were when the only important source of fluoride was water. Investigators seeking to examine the possible relation between fluoride intake and health outcomes, such as dental caries, fluorosis, or quality of bone, need to be aware of the complex situation that exists today. It is no longer feasible to estimate with reasonable accuracy the level of fluoride exposure simply on the basis of concentration in drinking water supply. FLUORIDE ABSORPTION Approximately 75-90% of the fluoride ingested each day is absorbed from the alimentary tract. The half-time for absorption is approximately

Intake, Metabolism, and Disposition of Fluoride 129 30 minutes, so peak plasma concentrations usually occur within 30

0 minutes. Absorption across the oral mucosa is limited and probably accounts for less than I% of the daily intake. Absorption from the stomach occurs readily and is inversely related to the pH of the gastric contents (Whitford and Pashiey, 1984

. Most of the fluoride that enters the intestine will be absorbed rapidly. It was generally believed that fluoride excreted in the feces was never absorbed, although several studies with rats (G.M. Whitford, Medical College of Georgia, Augusta, unpublished data, 1992) indicate that a diet high in calcium or parenteral administration of fluoride can result in fecal fluoride excretion rates that exceed fluoride intake. High concentrations of dietary calcium and other cations that form insoluble complexes with fluoride can reduce fluoride absorption from the gastrointestinal tract. The mechanism of fluoride absorption has received considerable research attention and has led to the conclusion that diffusion is the underlying process. Absorption across the oral and gastric mucosae is strongly pH-dependent. That finding is consistent with the hypothesis that hydrofluoric acid (pKa = 3.4) is the permeating moiety. Results from studies with rats indicate that fluoride absorption across the in- testinal mucosa is not pH-dependent (Nopakun and Messer, 1989

. FLUORIDE IN PLASMA There are two general forms of fluoride in human plasma. The ionic form is the one of interest in dentistry, medicine, and public health. Tonic fluoride is detectable by the ion-specific electrode. It is not bound to proteins or other components of plasma or to soft tissues. The other form consists of several fat-soluble organic fluorocompounds. These can be contaminants derived from food processing and packaging. Perfluoro- octanoic acid (octanoic acid fully substituted with fluoride) has been identified as one of the fluorocompounds (Guy, 1979

. The biological fate and importance of the organic fluorocompounds remains largely unknown. The extent to which the fluorine in these compounds is ex- changeable with the ionic fluoride pool has not been determined. The concentration of ionic fluoride in soft and hard tissues is directly related to the amount of ionic fluoride intake, but that of the fluorocompounds is not. Neither form is homeostatically controlled (Guy, 1979 Whitford and Williams, 1986

130 Health Effects of Ingested Fluoride Provided that water is the major source of fluoride intake, fasting plasma fluoride concentrations of healthy young or middIe-aged adults expressed as micromoles per liter are roughly equal to the fluoride concentrations in drinking water expressed as milligrams per liter. Plasma fluoride concentrations, however, tend to increase slowly over the years until the sixth or seventh decade of life when they, like fluoride concentrations in bone, tend to increase more rapidly. The reason for that change is uncertain but might be due to declining renal function or increasing resorption of bone crystals with low fluoride concentrations (leaving an increased density of crystals with high fluoride concentra- tions). Cord-blood plasma concentrations are 75-80% as high as mater- nal plasma concentrations, indicating that fluoride freely crosses the placenta (Shen and Taves, 1974

. The balance of fluoride in the neonate can be positive or negative during the early months of life, depending on whether intake is sufficient to maintain the plasma concentration that existed at the time of birth (Ekstranct et al., 1984

. TISSUE DISTRIBUTION As indicated by the results of short-term OFF isotope studies with rats, a steady-state distribution exists between the fluoride concentrations in plasma or extracellular fluid and the intracellular fluid of most soft tissues (Whitford et al., 1979

. Intracellular fluoride concentrations are lower, but they change proportionately and simultaneously with those of plasma. With the exception of the kidney, which concentrates fluoride within We renal tubules, tissue-to-plasma (T/P) fluoride ratios are less than I.0. In those cases in which the T/P ratio exceeds unity, as might occur in the aorta or the placenta near term, ectopic calcification should be suspected. Most of the published data on soft-tissue concentrations in humans were obtained with analytical methods that were insensitive and nonspecific or that hac> excessively high blanks. Further work is needed using modern analytical techniques, such as the ion-specific electrode after isolation of fluoride with the hexamethyIdisiloxane-facilitated dif- fusion method of Taves (1968) and modified by Whitford (19891. VenkateswarIu (1990) described and compared the merits of a variety of analytical methods for the determination of fluoride. The fluoride concentrations of several of the specializeci body fluids, including gingival crevicular fluid, ductal saliva, bile, and urine, are also

Stake, Metabolism, and Disposition of Fluoride 131 related to those of plasma in a steady-state manner. The fluoride con- centrations of breast milk and cerebrospinal fluid tend to be related to those of plasma, but they respond slowly to changes in plasma fluoride concentrations (Spak et al., 19X3

. The mechanism underlying the transmembrane migration of fluoride appears to be the diffusion equilibrium of hydrogen fluoride (Whitford, 1989

. Thus, factors that change the magnitude of transmembrane or transepithelial pH gradients will affect the tissue distribution of fluoride accordingly. In general, epithelia ant! cell membranes of most tissues appear to be essentially impermeable to the fluoride ion, which is charger] and has a large hydrated radius. Approximately 99% of the body burden of fluoride is associated with calcif

ect tissues. Of the fluoride absorber! by the young or middle-aged adult each day, approximately 50% will be associated with calcifies! tissues within 24 hours and the remainder will be excreted in urine. This 50:50 distribution is shifted strongly in favor of greater retention in the very young. Increased retention is due to the large surface area provided by numerous and loosely organized developing bone crystallites, which increase the clearance rate of fluoride from plasma by the skeleton (Whitford, 1989

. Accordingly, the peak plasma fluoride concentrations and the areas uncler the time-plasma concentration curves are directly related to age during the period of skeletal development. Due to de- creased accretion and increased resorption of bone, the 50:50 distribution is probably shifted in favor of greater excretion in the later years of life, but less is known about that. Fluoride is strongly but not irreversibly bound to apatite and other calcium phosphate compounds that might be present in calcified tissues. In the short term, fluoride might be mobilized from the hydration shells and the surfaces of bone crystallites (and presumably dentin ant! develop- ing enamel crystallites) by isotonic or heteroionic exchange. In the long term, the ion is mobilized by the normal process of bone remodeling. Waterhouse et al. (1980) reported that human serum fluoride concentra- tions were increased following administration of Parathormone and decreased by administration of calcitonin. FLUORIDE EXCRETION Elimination of absorbed fluoride from the body occurs almost ex

132 Health Effects of Ingested Fluoride c

usively via the kidneys. As noted above, about 10-25% of the daily intake of fluoride is not absorbed and remains to be excreted in feces. Data from the 1940s indicated that the amount of fluoride excreted in sweat could nearly equal urinary fluoride excretion under hot moist conditions (McClure et al., 1945

. More recent data obtained with modern analytical techniques (G.M. Whitford, Medical College of Georgia, Augusta, unpublished data, 1992), however, indicate that sweat fluoride concentrations are very low and similar to those of plasma (about I-3 mom/. Therefore, sweat is probably a quantitatively minor route for fluoride excretion under even extreme environmental conditions. The clearance rate of fluoride from plasma is essentially equal to the sum of the clearances by calcified tissues and kidneys. The renal clear- ances of chloride, iodide, and bromide in healthy young or middIe-aged adults are typically less than I.0 mL per minute, but the renal clearance of fluoride is approximately 35 mL per minute (Waterhouse et al., 1980 Cowell and Taylor, 1981 SchiM and Binswanger, 19X2

. Little is known about the renal handling of fluoride by infants, young children, and the elderly. A 600-day longitudinal study of fluoride pharmaco- kinetics Mat began with weanling dogs, however, indicated that the renal clearance of fluoride factored by body weight (milliliter per minute per kilogram) was independent of age (Whitford, 19891. In patients with compromised renal function where the glomerular filtration rate fails to 30% of normal on a chronic basis, fluoride excretion might decline sufficiently to result in increased soft- and hard-tissue fluoride concentra- tions (Schiffl and Binswanger, 19801. Renal handling, tissue concentra- tions, and effects of fluoride in renal patients are subjects in need of further research. Fluoride is freely filtered through the giomerular capillaries and undergoes tubular reabsorption in varying degrees. There is no evidence for net tubular secretion or a tubular transport maximum of the ion. The renal clearance of fluoride is directly related to urinary pH (VVhitford et al., 1976) and, under some conditions, to urinary flow rate (Chen et al., 19561. Recent data from stop-flow studies with dogs indicate that fluo- ride reabsorption is greatest from the distal nephron, the site where the tubular fluid is acidified (Whitford and Pashiey, 19911. As in the cases of gastric absorption and transmembrane migration, the mechanism for the tubular reabsorption of fluoride appears to be He diffusion of hydro- gen fluoride. Thus, factors that affect urinary pH such as diet, drugs, metabolic or respiratory disorders, and altitude of residence, have been

Stake, Metabolism, arid Disposition of Fluoride 133 shown or can be expected to affect the extent to which absorbed fluoride is retained in the body (Whitford, 1989

. RECOMMENDATIONS Further research is needed in the following areas: · Determine and compare the intake of fluoride from all sources, including fluoride-containing dental products, in fluoridated and non- fluoridated communities. That information would improve our under- standing of trends in dental caries, dental fluorosis, and possibly other disorders or diseases. · Determine the effects of factors that affect human acid-base balance and urinary pH on the metabolic characteristics, balance, and tissue concentrations of fluoride. · Determine the metabolic characteristics of fluoride in infants, young children, and the elderly. · Determine prospectively the metabolic characteristics of fluoride in patients with progressive renal disease. · Using preparative and analytical methods now available, determine soft-tissue fluoride concentrations and their relation to plasma fluoride concentrations. Consider the relation of tissue concentrations to variables of interest, including past fluoride exposure and age. · Identify the compounds that compose the "organic fluoride pool" in human plasma and determine their sources, metabolic characteristics, fate, and biological importance.


Fluoride is the ionic form of fluorine, the thirteenth most abundant element in the earth’s crust. It is released into the environment naturally in both water and air. Its concentration in water is variable (1). Water is the major dietary source of fluoride. The variability in water content explains much of the variability in total fluoride intake. Other important sources of fluoride are tea, seafood that contains edible bones or shells, medicinal supplements, and fluoridated toothpastes (2). Fluoride compounds are also produced by some industrial processes that use the mineral apatite, a mixture of calcium phosphate compounds (2). Dietary fluoride is absorbed rapidly in the stomach and small intestine. One-quarter to one-third of the absorbed fluoride is taken up into calcified tissues, whereas the rest is lost in the urine (3𠄶). In bone and teeth, fluoride can displace hydroxyl ions from hydroxyapatite to produce fluorapatite or fluorohydroxyapatite. About 99% of total body fluoride is contained in bones and teeth (3), and the amount steadily increases during life. The recommended intake for fluoride is expressed as an adequate intake rather than recommended dietary allowance, because of the limited data available to determine the population needs. The adequate intake for fluoride is 0.7 mg daily for toddlers, rising to 3 mg daily for adult women and 4 mg daily for adult men. It remains unclear whether fluoride is truly essential, although fluoride may have some beneficial effects (2). Once taken up into bone, fluoride appears to increase osteoblast activity and bone density, especially in the lumbar spine (7). Fluoride has been suggested as a therapy for osteoporosis since the 1960s, but despite producing denser bone, fracture risk is not reduced. Indeed, there is some evidence that nonvertebral fractures may be increased (8). The only known association with low fluoride intake is the risk of dental caries, acting through both pre-eruptive and post-eruptive mechanisms (5). The American Dental Association strongly supports fluoridation of community drinking water supplies (4) however, strong contradictory opinions also are held (9).

Dental caries is an infectious and multifactorial disease afflicting most people in industrialized and developing countries. Fluoride reduces the incidence of dental caries and slows or reverses the progression of existing lesions (10). Although pit and fissure sealants, meticulous oral hygiene, and appropriate dietary practices contribute to caries prevention and control, the most effective and widely used approaches include fluoride use (11).

The first 𠆊rtificial’ water fluoridation for caries control was introduced in 1945 and 1946 in the United States (US) and Canada, respectively, and it was expected that caries prevalence would be reduced by as much as 50% (12). The success of water fluoridation in preventing and controlling dental caries led to the development of several fluoride-containing products, including toothpaste, mouth rinse, dietary supplements, and professionally applied or prescribed gel, foam, or varnish.

Much of the research on the efficacy and effectiveness of individual fluoride modalities in preventing and controlling dental caries was conducted before 1980, when dental caries were more common and more severe. Several modes of fluoride use have evolved, each with its own recommended concentration, frequency of use, and dosage schedule. Simultaneously, recent resistance has been growing worldwide against fluoridation, emphasizing the possible risk of toxicity. Thus, health-care professionals and the public need guidance regarding the debate around fluoridation. This review examines the different aspects of fluoridation, their effectiveness in dental caries prevention, and their risks.

Check the label on your toothpaste to see if fluoride is an ingredient. You should also check for the ADA (American Dental Association) Seal of Approval to ensure that your toothpaste contains the proper amount of fluoride. If it’s not fluoridated, consider switching.

Water fluoridation is the adjustment of fluoride levels in the community water supply to the optimum level to protect oral health. By simply drinking tap water in communities with a fluoridated water supply, people can benefit from fluoride’s protection from decay. Research for the past 60 years has shown community water fluoridation to be safe and the single most effective public health measure to prevent tooth decay in adults and children. Water fluoridation is endorsed by nearly every major national and international health organization including the American Dental Association, American Medical Association, World Health Organization and the U.S. Centers for Disease Control (CDC).


Since the mid-20th century, it has been discerned from population studies (though incompletely understood) that fluoride reduces tooth decay. Initially, researchers hypothesized that fluoride helped by converting tooth enamel from the more acid-soluble mineral hydroxyapatite to the less acid-soluble mineral fluorapatite. However, more recent studies showed no difference in the frequency of caries (cavities) between teeth that were pre-fluoridated to different degrees. Current thinking is that fluoride prevents cavities primarily by helping teeth that are in the very early stages of tooth decay. [3]

When teeth begin to decay from the acid produced by sugar-consuming bacteria, calcium is lost (demineralization). However, teeth have a limited ability to recover calcium if decay is not too far advanced (remineralization). Fluoride appears to reduce demineralization and increase remineralization. Also, there is some evidence that fluoride interferes with the bacteria that consume sugars in the mouth and make tooth-destroying acids. [3] In any case, it is only the fluoride that is directly present in the mouth (topical treatment) that prevents cavities fluoride ions that are swallowed do not benefit the teeth. [3]

Water fluoridation is the controlled addition of fluoride to a public water supply in an effort to reduce tooth decay in people who drink the water. [4] Its use began in the 1940s, following studies of children in a region where water is naturally fluoridated. It is now used widely in public water systems in the United States and some other parts of the world, such that about two-thirds of the U.S. population is exposed to fluoridated water supplies [5] and about 5.7% of people worldwide. [6] Although the best available evidence shows no association with adverse effects other than fluorosis (dental and, in worse cases, skeletal), most of which is mild, [7] water fluoridation has been contentious for ethical, safety, and efficacy reasons, [6] and opposition to water fluoridation exists despite its widespread support by public health organizations. [8] The benefits of water fluoridation have lessened recently, presumably because of the availability of fluoride in other forms, but are still measurable, particularly for low-income groups. [9] Systematic reviews in 2000 and 2007 showed significant reduction of cavities in children exposed to water fluoridation. [10]

Sodium fluoride, tin difluoride, and, most commonly, sodium monofluorophosphate, are used in toothpaste. In 1955, the first fluoride toothpaste was introduced in the United States. Now, almost all toothpaste in developed countries is fluoridated. For example, 95% of European toothpaste contains fluoride. [9] Gels and foams are often advised for special patient groups, particularly those undergoing radiation therapy to the head (cancer patients). The patient receives a four-minute application of a high amount of fluoride. Varnishes, which can be more quickly applied, exist and perform a similar function. Fluoride is also often present in prescription and non-prescription mouthwashes and is a trace component of foods manufactured using fluoridated water supplies. [11]

Pharmaceuticals Edit

Of all commercialized pharmaceutical drugs, twenty percent contain fluorine, including important drugs in many different pharmaceutical classes. [12] Fluorine is often added to drug molecules during drug design, as even a single atom can greatly change the chemical properties of the molecule in desirable ways.

Because of the considerable stability of the carbon–fluorine bond, many drugs are fluorinated to delay their metabolism, which is the chemical process in which the drugs are turned into compounds that allows them to be eliminated. This prolongs their half-lives and allows for longer times between dosing and activation. For example, an aromatic ring may prevent the metabolism of a drug, but this presents a safety problem, because some aromatic compounds are metabolized in the body into poisonous epoxides by the organism's native enzymes. Substituting a fluorine into a para position, however, protects the aromatic ring and prevents the epoxide from being produced. [ citation needed ]

Adding fluorine to biologically active organic compounds increases their lipophilicity (ability to dissolve in fats), because the carbon–fluorine bond is even more hydrophobic than the carbon–hydrogen bond. This effect often increases a drug's bioavailability because of increased cell membrane penetration. [13] Although the potential of fluorine being released in a fluoride leaving group depends on its position in the molecule, [14] organofluorides are generally very stable, since the carbon–fluorine bond is strong.

Fluorines also find their uses in common mineralocorticoids, a class of drugs that increase the blood pressure. Adding a fluorine increases both its medical power and anti-inflammatory effects. [15] Fluorine-containing fludrocortisone is one of the most common of these drugs. [16] Dexamethasone and triamcinolone, which are among the most potent of the related synthetic corticosteroid class of drugs, contain fluorine as well. [16]

Several inhaled general anesthetic agents, including the most commonly used inhaled agents, also contain fluorine. The first fluorinated anesthetic agent, halothane, proved to be much safer (neither explosive nor flammable) and longer-lasting than those previously used. Modern fluorinated anesthetics are longer-lasting still and almost insoluble in blood, which accelerates the awakening. [17] Examples include sevoflurane, desflurane, enflurane, and isoflurane, all hydrofluorocarbon derivatives. [18]

Prior to the 1980s, antidepressants altered not only serotonin uptake but also the uptake of altered norepinephrine the latter caused most of the side effects of antidepressants. The first drug to alter only the serotonin uptake was Prozac it gave birth to the extensive selective serotonin reuptake inhibitor (SSRI) antidepressant class and is the best-selling antidepressant. Many other SSRI antidepressants are fluorinated organics, including Celexa, Luvox, and Lexapro. [19] Fluoroquinolones are a commonly used family of broad-spectrum antibiotics. [20]

Molecular structures of several fluorine-containing pharmaceuticals
Lipitor (atorvastatin) 5-FU (fluorouracil) Florinef (fludrocortisone) Isoflurane

Scanning Edit

Compounds containing fluorine-18, a radioactive isotope that emits positrons, are often used in positron emission tomography (PET) scanning, because the isotope's half-life of about 110 minutes is usefully long by positron-emitter standards. One such radiopharmaceutical is 2-deoxy-2-( 18 F)fluoro-D-glucose (generically referred to as fludeoxyglucose), commonly abbreviated as 18 F-FDG, or simply FDG. [21] In PET imaging, FDG can be used for assessing glucose metabolism in the brain and for imaging cancer tumors. After injection into the blood, FDG is taken up by "FDG-avid" tissues with a high need for glucose, such as the brain and most types of malignant tumors. [22] Tomography, often assisted by a computer to form a PET/CT (CT stands for "computer tomography") machine, can then be used to diagnose or monitor treatment of cancers, especially Hodgkin's lymphoma, lung cancer, and breast cancer. [23]

Natural fluorine is monoisotopic, consisting solely of fluorine-19. Fluorine compounds are highly amenable to nuclear magnetic resonance (NMR), because fluorine-19 has a nuclear spin of 1 ⁄ 2 , a high nuclear magnetic moment, and a high magnetogyric ratio. Fluorine compounds typically have a fast NMR relaxation, which enables the use of fast averaging to obtain a signal-to-noise ratio similar to hydrogen-1 NMR spectra. [24] Fluorine-19 is commonly used in NMR study of metabolism, protein structures and conformational changes. [25] In addition, inert fluorinated gases have the potential to be a cheap and efficient tool for imaging lung ventilation. [26]

Oxygen transport research Edit

Liquid fluorocarbons have a very high capacity for holding gas in solution. They can hold more oxygen or carbon dioxide than blood does. For that reason, they have attracted ongoing interest related to the possibility of artificial blood or of liquid breathing. [27]

Blood substitutes are the subject of research because the demand for blood transfusions grows faster than donations. In some scenarios, artificial blood may be more convenient or safe. Because fluorocarbons do not normally mix with water, they must be mixed into emulsions (small droplets of perfluorocarbon suspended in water) in order to be used as blood. [28] [29] One such product, Oxycyte, has been through initial clinical trials. [30] [31]

Possible medical uses of liquid breathing (which uses pure perfluorocarbon liquid, not a water emulsion) involve assistance for premature babies or for burn victims (if normal lung function is compromised). Both partial and complete filling of the lungs have been considered, although only the former has undergone any significant tests in humans. Several animal tests have been performed and there have been some human partial liquid ventilation trials. [32] One effort, by Alliance Pharmaceuticals, reached clinical trials but was abandoned because of insufficient advantage compared to other therapies. [33]

Nanocrystals represent a possible method of delivering water- or fat-soluble drugs within a perfluorochemical fluid. The use of these particles is being developed to help treat babies with damaged lungs. [34]

Perfluorocarbons are banned from sports, where they may be used to increase oxygen use for endurance athletes. One cyclist, Mauro Gianetti, was investigated after a near-fatality where PFC use was suspected. [35] [36] Other posited applications include deep-sea diving and space travel, applications that both require total, not partial, liquid ventilation. [37] [38] The 1989 film The Abyss depicted a fictional use of perfluorocarbon for human diving but also filmed a real rat surviving while cooled and immersed in perfluorocarbon. [39] (See also list of fictional treatments of perfluorocarbon breathing.)

An estimated 30% of agrichemical compounds contain fluorine. [40] Most of them are used as poisons, but a few stimulate growth instead.

Sodium fluoroacetate has been used as an insecticide, but it is especially effective against mammalian pests. [41] The name "1080" refers to the catalogue number of the poison, which became its brand name. [42] Fluoroacetate is similar to acetate, which has a pivotal role in the Krebs cycle (a key part of cell metabolism). Fluoroacetate halts the cycle and causes cells to be deprived of energy. [42] Several other insecticides contain sodium fluoride, which is much less toxic than fluoroacetate. [43] Insects fed 29-fluorostigmasterol use it to produce fluoroacetates. If a fluorine is transferred to a body cell, it blocks metabolism at the position occupied. [44]

Trifluralin was widely used in the 20th century, for example, in over half of U.S. cotton field acreage in 1998. [45] ) Because of its suspected carcinogenic properties some Northern European countries banned it in 1993. [46] As of 2015, the European Union has banned it, although Dow made a case to cancel the decision in 2011. [47]

Biologically synthesized organofluorines are few in number, although some are widely produced. [48] [49] The most common example is fluoroacetate, with an active poison molecule identical to commercial "1080". It is used as a defense against herbivores by at least 40 green plants in Australia, Brazil, and Africa [42] other biologically synthesized organofluorines include ω-fluoro fatty acids, fluoroacetone, and 2-fluorocitrate. [49] In bacteria, the enzyme adenosyl-fluoride synthase, which makes the carbon–fluorine bond, has been isolated. The discovery was touted as possibly leading to biological routes for organofluorine synthesis. [50]

Fluoride is considered a semi-essential element for humans: not necessary to sustain life, but contributing (within narrow limits of daily intake) to dental health and bone strength. Daily requirements for fluorine in humans vary with age and sex, ranging from 0.01 mg in infants below 6 months to 4 mg in adult males, with an upper tolerable limit of 0.7 mg in infants to 10 mg in adult males and females. [51] [52] Small amounts of fluoride may be beneficial for bone strength, but this is an issue only in the formulation of artificial diets. [53] (See also fluoride deficiency.)

Maintain a Healthy Mouth

My dental hygienist Hindy – whom I’ve been going to for 15 years – is amazed at the condition of my gums and teeth. You see, while I was never prone to cavities, before I started on the Osteoporosis Reversal Program my gums were red, swollen, and bleeding easily. I had to get professional cleanings every three months to prevent periodontal problems.

Soon after following the program, my gums did a 180 degree turnaround. So much so that Hindy was stunned. She asked me what had changed, and I told her about the Osteoporosis Reversal Program and how it balances the body and the pH. As it happens, she had also been diagnosed with osteoporosis, so she got on the program right away.

Besides switching to natural and fluoride-free toothpaste, I have recently started using a sonic toothbrush. It not only keeps my teeth clean and bright white, it also massages the gums and gently removes plaque. I’ve had an electric toothbrush for several years, and it is certainly better than a manual toothbrush. But here’s the big difference: sonic toothbrushes generate between 30,000 and 40,000 brush strokes per minute while electric toothbrushes generate between 3,000 and 7,500 per minute. Compare to this manual toothbrushing at about 300 per minute.

Researchers have shown that a clean mouth, free of inflammation and irritants, may prevent health problems. And if you’ve taken osteoporosis drugs in the past, it’s especially smart to avoid dental problems and gum issues. So stay away from fluoride, brush and floss often, and keep smiling, because you’re on the right track!


1 Pendrys DG, Katz RV., “Risk of enamel fluorosis associated with fluoride supplementation, infant formula and fluoride dentifrice use”, American Journal of Epidemiology, 1989 130:1199-1208.
2 Sowers M, et al. (1991). A prospective study of bone mineral content and fracture in communities with differential fluoride exposure. American Journal of Epidemiology. 133: 649-660.
3 Cooper C, et al. (1990). Water fluoride concentration and fracture of the proximal femur. J Epidemiol Community Health 44: 17-19.
4 Susheela AK, Sharma YD, “Fluoride poisoning and the effects of collagen biosynthesis of osseous and non-osseous tissue”, Toxicological European Research, 1981 3 (2): 99-104.

7. It Could Be Poisonous

There is a reason the FDA requires toothpastes to carry poison warning labels. If you swallow too much toothpaste or fluoride, you could suffer from acute poisoning and even death. You may think that this would require a lot of fluoride, but one tube of toothpaste contains enough fluoride to kill a small child. Though this severe type of poisoning is rare, lower doses can also cause symptoms of poisoning like nausea, vomiting, headaches, and gastric pain.

Who is Likely to Have an Adverse Reaction to Fluoride, and What are the Symptoms?

Fluoride toxicity has been widely studied because it has the potential to affect anyone, not just those of us who are already diagnosed with an autoimmune disease such as Hashimoto’s. Ingesting too much fluoride can cause damage to the thyroid gland and hypothyroid symptoms in an individual who was previously healthy. This includes children, men and women.

However, as I mentioned, there is research to support that fluoride toxicity increases with each generation – so if your mother had fluoride toxicity, it is likely you will be more susceptible, and your children even more so, and so on.

Acute oral exposure to high levels of fluoride may cause nausea, vomiting, abdominal pain, diarrhea, drowsiness, headaches, polyuria (excessive urination) and polydipsia (excessive thirst), coma, convulsions, cardiac arrest, and even death.

Chronic excessive intake of fluoride can lead to many diseases such as osteoporosis, arthritis, cancer, infertility, brain damage, Alzheimer’s, autoimmune thyroid disease, DNA damage, gastrointestinal irritation, kidney dysfunction, calcification of teeth (known as dental fluorosis), and much more.

9) Minimize Consumption of Mechanically-Deboned Chicken:

Most meats that are pulverized into a pulp form (e.g., chicken fingers, chicken nuggets) are made using a mechanical deboning processes. This mechanical deboning process increases the quantity of bone particles in the meat. Since bone is the main site of fluoride accumulation in the body, the higher levels of bone particle in mechanically deboned meat results in significantly elevated fluoride levels. Of all the meats that are mechanically deboned, chicken meat has consistently been found to have the highest levels. Thus, minimize consumption of mechanically-deboned chicken.

Why do we have fluoride in our water?

Fluoride is found naturally in soil, water, and foods. It is also produced synthetically for use in drinking water, toothpaste, mouthwashes and various chemical products.

Water authorities add fluoride to the municipal water supply, because studies have shown that adding it in areas where fluoride levels in the water are low can reduce the prevalence of tooth decay in the local population.

Tooth decay is one of the most common health problems affecting children. Many people worldwide cannot afford the cost of regular dental checks, so adding fluoride can offer savings and benefits to those who need them.

However, concerns have arisen regarding fluoride’s effect on health, including problems with bones, teeth, and neurological development.

Excessive exposure to fluoride has been linked to a number of health issues.

Dental fluorosis

A fluoride content of 0.7 ppm is now considered best for dental health. A concentration that is above 4.0 ppm could be hazardous.

Exposure to high concentrations of fluoride during childhood, when teeth are developing, can result in mild dental fluorosis. There will be tiny white streaks or specks in the enamel of the tooth.

This does not affect the health of the teeth, but the discoloration may be noticeable.

Breastfeeding infants or making up formula milk with fluoride-free water can help protect small children from fluorosis.

Children below the age of 6 years should not use a mouthwash that contains fluoride. Children should be supervised when brushing their teeth to ensure they do not swallow toothpaste.

Skeletal fluorosis

Excess exposure to fluoride can lead to a bone disease known as skeletal fluorosis. Over many years, this can result in pain and damage to bones and joints.

The bones may become hardened and less elastic, increasing the risk of fractures. If the bones thicken and bone tissue accumulates, this can contribute to impaired joint mobility.

Thyroid problems

In some cases, excess fluoride can damage the parathyroid gland. This can result in hyperparathyroidism, which involves uncontrolled secretion of parathyroid hormones.

This can result in a depletion of calcium in bone structures and higher-than-normal concentrations of calcium in the blood.

Lower calcium concentrations in bones make them more susceptible to fractures.

Neurological problems

In 2017, a report was published suggesting that exposure to fluoride before birth could lead to poorer cognitive outcomes in the future.

The researchers measured fluoride levels in 299 women during pregnancy and in their children between the ages of 6 and 12 years. They tested cognitive ability at the ages of 4 years and between 6 and 12 years. Higher levels of fluoride were associated with lower scores on IQ tests.

In 2014, fluoride was documented as a neurotoxin that could be hazardous to child development, along with 10 other industrial chemicals, including lead, arsenic, toluene, and methylmercury.

Other health problems

According to the International Association of Oral Medicine and Toxicology (IAOMT), an organization that campaigns against the use of added fluoride, it may also contribute to the following health problems:

    and other skin problems
  • cardiovascular problems, including arteriosclerosis and arterial calcification, high blood pressure, myocardial damage, cardiac insufficiency, and heart failure
  • reproductive issues, such as lower fertility and early puberty in girls
  • thyroid dysfunction
  • conditions affecting the joints and bones, such as osteoarthritis, bone cancer, and temporomandibular joint disorder (TMJ)
  • neurological problems, possibly leading to ADHD

One review describes fluoride as an “extreme electron scavenger” with an “insatiable appetite for calcium.” The researchers call for the balance of risks and benefits to be reconsidered.

Fluoride poisoning

Acute, high-level exposure to fluoride can lead to:

  • abdominal pain
  • excessive saliva
  • nausea and vomiting
  • seizures and muscle spasms

This will not result from drinking tap water. It is only likely to happen in cases of accidental contamination of drinking water, due, for example to an industrial fire or explosion.

It is worth remembering that many substances are harmful in large quantities but helpful in small amounts.

Fluoride is added to many dental products.

Flouride exists in many water supplies, and it is added to drinking water in many countries.

It is also used in the following dental products:

  • toothpaste
  • cements and fillings
  • gels and mouthwashes
  • varnishes
  • some brands of floss
  • fluoride supplements, recommended in areas where water is not fluoridated

Non-dental sources of flouride include:

  • drugs containing perfluorinated compounds
  • food and beverages made with water that contains fluoride
  • pesticides
  • waterproof and stain-resistant items with PFCs

Excess fluoride exposure may come from:

  • public water fluoridation
  • high concentrations of fluoride in natural fresh water
  • fluoridated mouthrinse or toothpaste
  • untested bottled water
  • inappropriate use of fluoride supplements
  • some foods

Not all fluoride exposure is due to adding the chemical to water and dental products.

Some geographical areas have drinking water that is naturally high in fluoride , for example, southern Asia, the eastern Mediterranean, and Africa.