JOM Volume 27, Number 3, 2012 Review Article 123

Systemic Effects of Fluoridation

Michael Czajka1 1. PhD Candidate in Chemistry, School of Applied Sciences, RMIT University, Box 2476 GPO, Melbourne, Victoria, 3001, Australia Tel: 613-9925-2122, Fax: 613-9925-3747, Email: [email protected]

Abstract !is review article is written from a food chemistry perspective. It focuses on the systemic ef- fects of "uoride (rather than the e#ects of "uoride on the teeth) since "uoride research concentrates largely on the teeth to the virtual exclusion of systemic e#ects. !is is surprising given that "uoride is a known systemic toxin. About 400 million people (~6% of the world’s population) drink "uoridated water. !e e#ect of "uoride on the teeth is topical (directly on the teeth) and not systemic, so drinking "uoridated water has no bene$t. Fluoride is a lipid soluble neurotoxin and enzyme poison. Fluoride accumulates in the pineal gland (9,000 ppm on average) and bone. Dental "uorosis is a marker for skeletal "uorosis. At 1 ppm 32 % of US children have dental "uorosis. At 1 ppm some sections of the population (e.g. infants) will ingest too much "uoride. Un"uoridated and "uoridated countries have similar rates of tooth decay. Given that "uoridation of water supplies is not necessary to maintain a reduction in tooth decay and that the side e#ects of ingestion are undesirable, the practice is likely to come under increasing scrutiny. More studies on the systemic e#ects of "uoride are urgently required.

Introduction weight of 18.998 g/mol. Fluorine gas (F2) is Fluoride is added to water to protect yellow but does not exist in nature as it is too teeth against decay, yet it is considered a reactive. Fluorine is also the most electro- neurotoxin in the laboratory. Research about negative element. !uoride is primarily focussed on teeth with Fluoride (Figure 1, p.124) can be added little examination of other systemic e"ects to the water supply as hexa!uorosilicic acid (i.e., upon enzymes, bone, brain, thyroid, (H2SiF6), sodium ! uorosilicate (Na2SiF6, a pineal gland, etc). Maximum toxic dosages powder) or sodium !uoride (NaF, a powder). are unclear, as are maximum cumulative Water !uoridation is usually carried out us- dosages. Adding to the confusion, ! uoride ing hexa!uorosilicic acid (~23% in water), is considered non-toxic when added to wa- which is a by-product of the aluminum and ter, but toothpaste tubes have warnings to phosphate industries. seek medical help if you swallow even small Toothpastes most commonly contain amounts. Identifying !uorosis is di#cult and !uoride as sodium !uoride but also use stan- its symptoms can easily be mistaken for ar- nous ! uoride, sodium monophosphate or thritis or possibly chronic fatigue syndrome. ola!ur/decta!ur. As they are not normally Fluoride can be considered a food safety is- ingested they are not a signi$cant consider- sue since it is primarily ingested from water, ation when reviewing the systemic e"ects of and to a lesser extent, foods. !uoride. Almost all ! uoride research has been Fluorine Chemistry conducted on NaF (which dissociates into + - Fluorine (F) is element number 9 on the Na and F ). %e assumption has been that periodic table of elements and has a atomic H2SiF6 and Na2SiF6 dissociate into their 124 Journal of Orthomolecular Medicine Vol 27, No 3, 2012

Figure 1. Hexafluorosilicic acid (H2SiF6), sodium fluorosilicate (Na2SiF6), sodium fluoride (NaF), stannous fluoride (SnF2) and sodium monofluorophosphate (Na2PO3F)

Sn2+ Na+ F- F- F-

+ - + +4 component ions (eg. H , F , Na and Si ) was changed to permit the voluntary ad- when diluted and raised to a pH of 7. If this dition of fluoride to bottled water at levels happened, the e!ects of NaF and other com- of 0.6-1.0 mg/L. Nutrient reference val- plexes would be comparable. However, at pH ues for ANZ populations have been es- 3, the majority of the F is complexed with Si. tablished for different age groups (Table "e e!ects of NaF are di!erent than those of 1, below). the Si complexes: no e!ect was noticed with NaF, but with Si-#uoride complexes lead Does Fluoride Occur Naturally? levels in the blood increased three times in Fluoride occurs naturally in some foods 3 rats. "is is because the pH of stomach acid and in water. "e #uoride levels in water of is around 2: the ions recombine and Si-#u- most countries are low. Countries like China oride complexes, as well as other complexes, and India, on the other hand, have many are produced. areas where the natural levels of #uoride in What levels are Permitted in Foods? water are high enough to cause crippling skeletal # uorosis. "e levels in breast milk Food Standards Australia and New average only 0.033 ppm even when #uoride Zealand (ANZ) do not list fluoride as a intake is high.5 Levels in fresh food are rarely recognized food additive. However, in a consideration, except in tea which can add July, 2009, the ANZ food standards code between 1-9 mg/day of #uoride.5-7

Table 1. Fluoride nutrient reference values for Australian and New Zealand populations4

Population Subgroup Adequate Intake/AI Upper Limit/UL (mg/day) (mg/day) Infants 0-6 months 0.01 0.7 Infants 7-12 months 0.5 0.9 1-3 years 0.7 1.3 4-8 years 1.0 2.2 9-13 years 2.0 10.0 14-18 years 3.0 10.0

Males Females Males Females Adults 19+ years (including 4.0 3.0 10.0 10.0 pregnant /lactating women) Systemic E!ects of Fluoridation 125

How Much Fluoride is in Water? to 80%).8 Many enzymes are a"ected by In Australian water, !uoride is permitted !uoride (e.g., Judd lists 66 enzymes includ- at up to 2 ppm although it is normally main- ing P450 oxidases and enzymes involved in tained at around 0.9-1.0 ppm. Using the UL neurotransmitter synthesis16). When 2-10 of 0.7 mg/day (Table 1) it can be seen that mg/day of !uoride was administered to 15 any bottle-fed infant will surpass the UL individuals with hyperthyroidism (over a for !uoride every day. %e National Health period of 20-245 days), six individuals had and Research Council Dietary Guidelines signi$cant clinical improvements marked by recommends against this practice.8 Other an amelioration of tachycardia and tremor, countries also warn against the use of !uori- and a ceasing of their weight loss.17 %e dated water for bottle fed infants and other reduction in basal metabolic rates was at- high risk groups (e.g., dialysis patients),9 yet tributed to ! uoride inhibiting the thyroid ANZ food standards consider this practice iodide-concentrating mechanism.17 Similar to be safe and have stated on their website: daily intakes of !uoride might also have ad- “Bottled water with added !uoride is safe for verse e"ects upon the basal metabolic rates everyone and can be used to make up infant of euthyroid (i.e., normal thyroid function) formula.”10 individuals. How is Fluoride Increased In Foods? How Does Fluoride Interfere with Boiling water concentrates !uoride (by Enzymes? evaporation).11 Processing foods often in- Fluoride can interfere by attaching it- crease the amount of ! uoride (e.g., adding self to metal ions located at an enzyme’s ac- !uoridated water to a soup or reconstituting tive site or by forming competing hydrogen fruit juice using !uoridated water). bonds at the active site. Energy production is a"ected when this occurs. Fluoride might, Can Fluoride Be Removed? therefore, be a pathogenic factor in caus- %e simplest method of removing !uo- ing clinically signi$cant problems, such as ride is distillation.11 Reverse osmosis is also weakness, drowsiness, and cognitive impair- highly e"ective.11 Both these methods re- ment.18 move all other minerals from the water as well which may not be desirable. Activated Is Dental Fluorosis a Marker for Fluorosis? alumina (Al2O3) cartridges are an alternative It is also known that crippling skeletal method.11 Cartridges require regular chang- !uorosis is caused by excessive !uoride in- ing but there is no easy way to tell when this gestion (Figure 2, p.126). %us, dental !uo- should occur. rosis is a marker for skeletal ! uorosis and other serious physiological e"ects. Even at At What Dose Does Fluoride Have low levels of 1 ppm, 32% of US children are Undesirable Physiological E!ects? a"ected by dental !uorosis.19 Crippling skel- %e National Health and Medical Re- etal !uorosis may be produced by levels of search Council of Australia has deemed 10-20 mg/day over 10-20 years.20 10 mg/day of !uoride as the UL,8 but few toxicological studies have been carried out to What About Less Serious Fluorosis? prove this. Most studies have concentrated Fluoride levels of 0.9 ppm in naturally on the teeth and fewer studies on rest of the occurring water supplies (Xinjiang region of body. %e organs mostly a"ected by !uoride China, Hentian prefecture) may a"ect peo- include the brain,12,13 thyroid, parathyroid ple who are iodine de$cient, causing hear- and adrenal glands,14 and the pineal gland.15 ing loss, mental retardation and bone retar- However, !uoride concentrates in the bones dation.21 It is likely that iodine and !uoride (i.e., about 50% of ingested ! uoride is re- compete for similar binding sites in the hu- tained, but young children may retain up man body. When iodine is low, as in this ex- 126 Journal of Orthomolecular Medicine Vol 27, No 3, 2012

Figure 2. Severe dental fluorosis

Photo provided by: Kennedy D: China’s battle with crippling water. Corte Madera, CA. Green Planet Films. 2000. Retrieved from: [www.greenplanetfilms.org/product_info.php?products_id=176]. Used with permission

ample, there would be less competitive inhi- cult to prove chronic !uoride toxicity because bition, and more !uoride would be available this depends on the length of exposure, which to bind to various tissues within the human may stretch many decades. Acute lethal doses body. China has naturally occurring levels of can result from one signi$cant exposure. A le- !uoride, so the population consumes !uo - thal dose for children is 5-15 mg/kg !uoride. ride daily and their exposure varies accord- %us, as little as 35 mg can kill a 7 kg infant ing to how much they drink. In the Jiangsu while 5-10 g (32-64 mg/kg) can kill a 70 kg Province of China, Sihong county, !uoride adult.24 Acute !uoride poisoning was found to levels of 1.9 ppm (in naturally occurring have caused a fatality in a public water system water supplies) are associated with lowering in Alaska where the concentration was 150 population IQ (i.e., by 5-10 points).22 ppm (i.e., about 17.9 mg/kg).25A chronic dose %e pineal gland is the second most per- of 10 mg/day is often cited in the literature as fused organ in the body (after the kidneys) and the UL in adults.8 More than this amount per studies show it contains !uoride levels rang- day would put a person at risk for developing ing from 9,000-21,000 ppm. %e lower level chronic !uoride toxicity over time. Individu- approaches that of skeletal !uorosis and the als living in warmer climates, sports people upper level exceeds that of severe skeletal !uo- and diabetics are likely to ingest more than rosis.14 Rat studies show that !uoride accumu- 10 mg/day (i.e., equates to 10 L of water at 1 lates in the brain and is associated with both ppm), and are at risk for developing chronic hyperactivity (when exposed before birth) and !uoride toxicity, especially when all foods and hypoactivity (when exposed after birth).23 beverages (e.g., tea) and non-food sources (e.g., toothpaste) are included in an individu- What is the Toxic/Lethal Level of al’s calculated amount of ingested !uoride. It Fluoride? should be noted that toothbrushing does not Chronic toxic doses of !uoride can accu- by itself increase blood levels enough to nega- mulate over a long period of time. It is di#- tively in!uence bone production.26 However, Systemic E!ects of Fluoridation 127

when toothbrushing (i.e., provides 1,350- of aluminum into the brain in rat studies,34 1,500 mg/L or 1.35-1.50 g/L of !uoride) is which might have etiologic implications in combined with increased !uid intake and the human neurodegenerative diseases. regular intake of beverages like tea (i.e., can 6,7 Treating Fluoride Poisoning add 1-9 mg/day of !uoride), it is possible that individuals would be at risk for develop- Fluoride is a lipid soluble neurotoxin ab- ing chronic !uoride toxicity since their daily sorbed on contact. It is a substance that work- consumption might be more than 10 mg for ers are usually discouraged from working extended periods of time. with. Hydro!uoric acid (HF; Figure 4, below) is probably the best known source of !uoride Bio-Mimetic Molecules poisoning.35-37 Special training and extra pro- Fluoride can form complexes and fa- tective equipment is required to work with cilitate the uptake of every metal ion, such HF. Following absorption, HF binds to cal- 3+ 2+ as aluminium (Al ) and lead (Pb ), except cium (CaF2) and magnesium (MgF2) ions in for the alkali metals (i.e., lithium, sodium the body causing severe systemic e"ects. HF and potassium).3,27 For example (Figure 3, poisoning (including !uoride poisoning from below), the ! uoride-aluminum complex any exposure) is treated with calcium glu- - (AlF4 ) has about the same size and shape as conate (C12H22CaO14) and calcium chloride 3- phosphate (PO4 ). (CaCl2) intravenously to ameliorate hypocal- caemia, tetany, cardiac arrhythmias, and neu- 36-38 Figure 3. Tetra fluoroaluminate ion (AlF4-) rotoxicity resulting from !uoride excess. and phosphate ion (PO 3-) 4 Figure 4. Hydrofluoric Acid

Since energy production is partially Does Fluoride Have to be Ingested to dependent on having su#cient phosphate Work? ions, it is conceivable that ! uoride-metal According to the National Research complexes disrupt enzymatic function. For Council, “the major anticaries bene$t of !u- example, signalling G-proteins can become oride is topical and not systemic.”9 Fluoride - disrupted by AlF4 because this ! uoride- should therefore be placed directly on the metal complex can switch them on when no teeth to exert its therapeutic e"ects and does messenger has arrived.28,29 Since !uoride can not need to be ingested. Toothpaste usually 30,31 - cause goitre, AlF4 is implicated in inac- has a concentration of 1,350-1,500 ppm (i.e., tivating deiodinases.21,32 Fluoride interferes 1,350-1,500 mg/L or 1.35-1.50 g/L of !uo- with the body’s defence mechanisms against ride). While toothpaste is not a food item, reactive oxygen species, leading to lipid per- it is sometimes ingested accidently. Some oxidation and in!ammation, which suggests toothpaste includes a warning to call a hos- that !uoride might be implicated in a range pital if a small amount (pea sized amount of diseases characterized by increased oxida- ~0.25 mg) is ingested. In children under tive damage.33 Fluoride increases the uptake seven years of age, parents should only apply 128 Journal of Orthomolecular Medicine Vol 27, No 3, 2012

a pea-sized amount of ! uoride toothpaste Conclusion on the toothbrush and discourage swallow- Key points in this !uoride review are ing; otherwise, their children might ingest that ~6% of the world’s population drinks too much for their body weight.39 Children !uoridated water. %e action of !uoride is should be encouraged to rinse and/or spit af- topical (directly on the teeth) not systemic ter brushing as this will signi$cantly reduce (drinking it is not bene$cial). Fluoride is a !uoride ingestion from toothbrushing.40 lipid soluble neurotoxin and enzyme poi- son. Fluoride accumulates in the pineal Un"uoridated versus Fluoridated gland (9,000 ppm on average) and bone. Countries Dental !uorosis is a marker for skeletal !u- Only about 400 million people (~6%) orosis. At 1 ppm, 32% of US children have worldwide (out of ~7 billion) drink !uori- dental !uorosis. Even at one ppm, some dated water and most !uoridated water is in sections of the population (e.g. infants) will the United States. Only eight countries have ingest too much !uoride. Un!uoridated more than 50% of their populations drinking and !uoridated countries have similar rates !uoridated water.41 %e Centres for Disease of tooth decay. Given that !uoridation of Control and Prevention have stated that !u- water supplies is not necessary (applying oridation was one of the ten most important !uoride topically achieves the same e"ect) public health measures of the 20th century.42 and since un!uoridated populations have On the other hand, many countries (i.e., Bel- roughly the same rate of tooth decay, it is gium, Japan, Denmark, and the Netherlands) no longer necessary to !uoridate water to have removed !uoride citing a wide range of maintain a reduction in tooth decay. It is health concerns. Furthermore, none of these also a matter of some urgency that better countries have shown an increased incidence studies of the systemic e"ects of !uoride of dental caries (Figure 5, below). are carried out.

Figure 5. Tooth decay in 12 year olds: effects from four unfluoridated* and four fluoridated water supplies

(Adapted from: Connett P et al: The Case Against Fluoride. White River Junction, VT. Chelsea Green Publishing. 2010;38. Used with permission) Systemic E!ects of Fluoridation 129

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