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Fluoride: Friend or Foe?

We all brush our teeth... hopefully more than once a day. The choice is endless for the perfect minty, whitening, cavity-preventing toothpaste to make those pearly-whites flash the shiniest smile. And when we head to the dentist every 6 months, we want to hear nothing less than what a great job we are doing brushing and flossing with a "no cavities!" to send us on your way.

Fluoride is one of the most widely accepted ways that cavities are (supposedly) prevented in the United States. Fluoride is added to much of the water supply in our country and other countries worldwide. Yet, there is much controversy surrounding its use in regards to safety, efficacy but also medical choice and freedom.

So what exactly is fluoride? Fluorine was discovered in 1886 by Henri Mossan, in the form of a pale yellow gas that is highly reactive and can be found in soil, air, food and water as fluoride. In its various forms, fluorine is used in producing uranium, plastics, ceramics, pesticides, pharmaceuticals and in refrigeration and aerosol propellant applications. The study of the use of fluoride in water to prevent tooth decay started almost be accident. In 1909 two dental surgeons noticed that a group of people in parts of Colorado had brown-stained teeth. This phenomenon was noticed in a few other places in the country which at the time no one understood why. First, they uncovered that adults and older children whose permanent teeth had already calcified were not at risk of the brown stains... but the children who had not yet lost their baby teeth were at the highest risk for staining of their teeth. They also discovered, that those children whose teeth were stained browned, were also surprisingly the teeth most resistant to decay! (Yes, brown stained teeth seemed to be the least likely to be decayed!) In time and through studying different water supplies, these surgeons uncovered that the children whose teeth had browned were drinking water extremely high in fluoride. This intrigued researchers to investigate why these teeth seemed so strong. Studies began to investigate the effect of fluoride on tooth enamel. A study was set up in Grand Rapids, MI in which 30,000 school children were studied for prevention and reduction of dental caries when fluoridation of water at 1 part per million (ppm) was used. This was thought to be a low enough amount to prevent fluorosis (the name of the condition causing brown stains on teeth but also possible dangerous calcification in the body) but high enough to reap what was thought to be of great benefit to dental health. This study impacted the widespread decision to fluoridate community water supplies around 1950. (Elvove & Dean, 1937) (Peckham and Awofesco 2014)

Unfortunately, this study has been severely criticized for major flaws, including cherry picking data and selection bias including inconsistent sample sizes (sometimes as low as one child studied vs 18,000 in another city), selections for samples was different against both cities being compared, lack of control city, change of examiners and much more. This study although severely flawed contributed to the decision to introduce community water fluoridation. This decision occurred before final results from this study could be analyzed or before any other studies could be conducted. In a chain reaction, lead by the United States, other countries began to fluoridate their water supplies and the World Health Organization accepted it as an “effective oral health intervention.” Since this time, multiple countries and communities within our country have stopped water fluoridation due to rising health concerns, ethical debates, and questions regarding effectiveness. (Peckham and Awofesco 2014) (Sutton, 1959) When it comes to effectiveness of water fluoridation on prevention of cavities, fluoride shows some success when used topically. Yet, the effectiveness of this topical fluoride only works to help re-mineralize teeth, if the teeth enamel it is being used on have adequate amounts of both calcium and magnesium. If a person is undernourished or deficient in magnesium or calcium, fluoride actually has the opposite effect on teeth and makes them more prone to cavities! Multiple studies have questioned the true efficacy as the consensus for reduction of cavity occurrence is only about 14.6%. In addition, this consensus of 14.6% was concluded without accounting for improvements in oral hygiene. In more recent studies comparing kids who drink fluoridated water vs those who do not, there is actually little difference in the amount of cavities among the groups. (Warren et al, 2009) One recent review from Europe actually concludes that “water fluoridation is a crude and rather ineffective form of systemic fluoride treatment to prevent dental caries without a detectable threshold for dental and bone damage.” (European Commission, 2011)

So, what gives? So what if it isn’t as effective as we thought? It still helps some, right? Less cavities is better… But at what cost? Is Fluoride ingestion safe? Especially over the course of a lifetime in daily exposure through teeth brushing and water drinking?

First of all, dental caries are a multi-factorial condition resulting from bacterial infections that are impacted by environmental, behavioral, and lifestyle factors… including what food you eat, inadequate salivary flow, malnutrition (magnesium and calcium particularly), poor oral hygiene, the microbiome in the mouth and many others. Currently, over 90% of toothpastes contain fluoride. If you take a peak at the side of your toothpaste tube or the box it came in, you will notice a warning, “Keep out of reach of children under 6 yrs. of age. If more than used for brushing is accidentally swallowed, get medical help or contact a Poison Control Center right away.” This is alarming considering we not only ingest toothpaste (especially younger children that accidentally swallow it) but we also willingly drink water that is fluoridated. For younger children, the threshold for dangerous amounts of fluoride is much lower than adults. For kids that begin brushing their teeth at a younger age, they are much more likely to develop fluorosis (seen on teeth as faint white lines or streaks on the teeth that only occurs when developing teeth come into contact with too much fluoride). Boiling water also doubles the fluoride concentrations found in water so any foods or formulas prepared with boiling water increases the amount of fluoride exposure. If only fluorosis were simply a cosmetic issue, the concern would not be too great. But fluorosis also impacts the bones, joints and even the pineal gland in the brain through calcification There is evidence that fluoride negatively impacts the body in several ways including in the brain, bones, and thyroid. (Nakamoto & Rawls, 2018) Let’s start with the obvious... Fluoride is classified as a pollutant, not a nutrient or medication. Fluoride “deficiency” does not exist and there is no proof that the human body requires it for optimal health. There is no basis for a set “adequate intake” amount and no “optimal dose.” What we have is an amount, that 50+ years ago was studied as a potential “low enough” amount to prevent the browning of teeth. Unfortunately, we are unable to control any individual’s daily dose of fluoride. It is stated in the Public Health Services Review of Fluoride benefits and risks, “In 1991, the Centers for Disease Control (CDC) in the USA measured fluoride levels and found that where water is fluoridated between 0.7 and 1.2 ppm overall fluoride, total fluoride intake for adults was between 1.58 and 6.6 mg per day while for children it was between 0.9 and 3.6 mg per day and that there was at least a sixfold variation just from water consumption alone.” In another study, it was found that 90% of 3 month olds consumed well over 6 mg of fluoride daily, which both the EPA and WHO state is above the level that is safe to avoid skeletal fluorosis, which causes painful damage to bones and joints. (Levy et al, 2001) As briefly mentioned earlier, malnourished children low in magnesium and calcium are at greater risk for dental caries when exposed to fluoride which causes brittle teeth. It doesn’t stop there. The National Research Council in the USA for the Environmental Protection Agency took a review of evidence of adverse effects of fluoridation of water and found impact on cognitive impairment, hypothyroidism, dental and skeletal fluorosis, and cancer. (NRC, 2006) A meta-analysis was performed in 2012 of over 27 studies and researchers found strong indication that cognitive development was negatively impacted by fluoride ingestion. It was found that it caused a loss of intelligence of approximately 7-15 IQ points. Neutoxicity is a proven side effect of fluoride exposure. (PPL, 2008) Both neurological and psychological effects from fluoride have been documented since the 1930s including declines in mental activity, memory impairment, difficulty thinking and writing, chronic fatigue, headaches, hyperactivity and a diminished ability to focus (McClure, 1933) Sounds worth it for a few less trips to the dentist, huh?

Other studies have shown under-active thyroid attributed to fluoridated drinking water. (Susheela et al, 2005) Dental and skeletal fluorosis is common in areas where drinking water concentrations of fluoride reach

over 2ppm or where people are exposed to aluminum or fertilizer industries (both high in fluoride) showing that over

20% of these people have symptoms including joint pains, tingling or numbing sensations, and chronic back pain. Even at doses much smaller, such as 0.3 ppm, discoloration of the teeth still occurs. With the combination of water fluoridation and products in the market place with added fluoride, such as toothpastes and mouth washes, intake is well above the 1 mg/day suggested upper level of safe intake. Some studies have even found association with higher fluoride intake and higher cancer occurrence, particular uterine and bladder cancer and osteosarcoma. Further research is warranted in this area. (Peckham and Awofesco 2014)

In addition, recent research has been investigating the link between Autism Spectrum Disorder and chronic fluoride exposure. Fluoride has effects in the body on oxidative stress, inflammation and immuno-excitotoxicity which are all contributing factors to ASD. In addition, decreased levels of melatonin are common in those with ASD and calcification of the pineal gland due to fluorosis causes low levels of melatonin. Research is showing correlation between the increase of Autism diagnosis within countries with the highest levels of water fluoridation (including China, US, and Japan). There is no single cause to ASD but water fluoridation certainly may have its place at the table in potential causation. (Strunecka & Strunecky, 2019) Ethically speaking, considering fluoride’s potential harm and lack of effectiveness, where is the line drawn on individual choice regarding medication without consent? Where there is potential harm, there should be choice, yet when community water supplies are fluoridated, the choice is removed. In the name of dental health (which has proven to be weakly supported in scientific studies), water fluoridation has occurred in what the CDC reports as 74.4% of the population for 70 years. Yet, fluoride is not classified as a nutrient or medication, but rather, a pollutant. Medications are subject to strict guidelines in our country (and many others) yet fluoride is not subjected to these same standards. It poses the question, is it the right of any government to determine what is medically best for its citizens? How do you feel knowing these risks of fluoridation to your body and the bodies of your developing children?

To sum it up, fluoride can wreak havoc on the human body, causing neurotoxicity, cognitive impairment, low thyroid function, joint and bone damage, possible contribution to autism and cancer, and... at the most basic level, turn your teeth brown and/or splotchy. Sounds like a great reason to add this to community water supply…. Luckily, for you and I, we have options to reduce our exposure to fluoride. We can start by purchasing fluoride-free toothpastes and mouth washes. (Keep in mind, many of these toothpastes contain xylitol which is extremely toxic to dogs in small amounts… so if you are a pet owner, take precaution!) We can choose to live in communities with non-fluoridated water supplies, as some do exist in our country. We can politely decline fluoride treatment at the dentist and we can purchase water filters that remove fluoride and other compounds in our water supply that are harmful to our health. In addition, to prevent cavities, we can eat whole, real foods, reduce sugar intake and intake of fermentable carbohydrates, hydrate properly and often, and rinse well after eating, and practice good oral hygiene (fluoride-free, of course). Don’t take my word for it, do your own research. Look into what the science says regarding fluoride and come to your own conclusion. Use the tools at your disposal to inform yourself and think critically and as always, be your own advocate for health and wellness!

Comment below, do you use fluoride-free toothpaste? Do you believe it is ethical to add fluoride to community water supply?

References: Nakamoto, T., Rawls, HR, (2018) Fluoride Exposure in Early Life as the Possible Root Cause of Disease in Later Life. The Journal of Clinical Pediatric Dentistry (42)5 doi 10.17796/1053-4625-42.5.1 McClure F.J. A review of fluorine and its physiological effects. Physiol. Rev. 1933;13:277–300. doi: 10.1152/physrev.1933.13.3.277. Spittle B. Fluoride Fatigue: Fluoride Poisoning: Is Fluoride in your Drinking Water, and from Other Sources, Making you Sick? Paua Press Limited; Dunedin, New Zealand: 2008. p. 78. National Research Council (NRC) Fluoride in Drinking Water: A Scientific Review of EPA’s Standards. Washington, DC, USA: National Academies Press; 2006 Public Health Services US. Review of Fluoride Benefits and Risks. Table 11, p. 17, 1991, Patterns of fluoride intake from birth to 36 months. Levy SM, Warren JJ, Davis CS, Kirchner HL, Kanellis MJ, Wefel JS Public Health Dent. 2001 Spring; 61(2):70-7. Developmental fluoride neurotoxicity: a systematic review and meta-analysis. Choi AL, Sun G, Zhang Y, Grandjean P Environ Health Perspect. 2012 Oct; 120(10):1362-8. Susheela AK, Bhatnagar M, Vig K, Mondal NK. Excess fluoride ingestion and thyroid hormone derangements in children living in Delhi, India. Fluoride. 2005;38(2):98–108 Dental Fluorosis Trends in US Oral Health Surveys: 1986 to 2012. Neurath C, Limeback H, Osmunson B, Connett M, Kanter V, Wells CR JDR Clin Trans Res. 2019 Oct; 4(4):298-308. Sutton PRN. Fluoridation: Errors and Omissions in Experimental Trials. Melbourne, Australia: Melbourne University Press; 1959. Peckham S, Awofeso N. Water Fluoridation: A Critical Review of the Physiological Effects of Ingested Fluoride as a Public Health Intervention. ScientificWorldJournal. 2014;2014. doi:10.1155/2014/293019

Strunecka A, Strunecky O. Chronic Fluoride Exposure and the Risk of Autism Spectrum Disorder. Int J Environ Res Public Health. 2019;16(18). doi:10.3390/ijerph16183431 Dean H, Elvove E. Further studies on the minimum threshold of chronic endemic dental fluorosis. Public Health Reports. 1937;52:1249–1264 McDonagh, Marian S, Whiting PF, et al. A Systematic Review of Public Water Fluoridation. York, UK: University of York; (NHS Centres for Reviews and Dissemination Report 18).

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