The “F” Word: Fluoride…a 70 year controversy

When I was in Dental School, we were taught that Fluoride was like a vitamin. They taught us how to prescribe this “supplement” even to pregnant mothers…that was then- Science changes! Those of us who keep up with the research understand now that fluoride is not that wonderful game changer that would end cavities. The aim of science is not to open the door to infinite wisdom, but to set a limit to infinite error.

I wrote my first article on fluoride over 10 years ago. I never published it for fear of losing my license and having my dental peers black list me from the dental community. Today, the evidence and research based science is overwhelming- the research based evidence is in favor of the “no fluoride” understanding. The truth is: it is extremely easy to search for this information. The meta-analysis research is easily accessible to anyone: just search medical publications on PubMed.com. Unfortunately, many “scholars” are still hanging on to the 1950’s statement that “Fluoride is beneficial especially in low income sectors”; or that topical fluoride hardens tooth structure”, without taking into account that fluoride is basically everywhere: in our water, processed foods and Pharmaceuticals. Drugs used and prescribed everyday worldwide contain some type of fluoride; for example: Statins, antibiotics, anti diabetics and inhaled anesthetics. The scary fact is that according to studies, 50% of ingested fluoride is absorbed into the bones.

There are many accounts on how fluoride came to be adopted, but for the purpose of this article, we are only going to evaluate the most recent studies on the side effects of consuming fluoride. A thin strip of fluoride covering a child’s toothbrush contains 0.75-1.5mg which exceeds “recommended’ amounts even by prescription. Even more worrisome is that fluoride is cumulative- Would you give your child anything that had a blackbox warning from the FDA?? If more than a pea size is ingested, call POISON CONTROL. This warning is on every fluoride toothpaste. Do you use a PEA-SIZED amount of tooth paste??!! As Dr. Mark Briener states in The Brain-Mouth Connection: "How can anyone justify giving the same dose of any drug to an infant as to a 200lb man?" And, according to the FDA, fluoride is considered a drug.

The Research

1.  Fluoride exposure and cognitive neurodevelopment: Systematic review and dose-response meta-analysis. Veneri F, Vinceti M, Generali L, Giannone ME, Mazzoleni E, Birnbaum LS, Consolo U, Filippini T. Environ Res. 2023 Mar 15;221:115239. doi: 10.1016/j.envres.2023.115239. Epub 2023 Jan 10. PMID: 36639015 Review.

2. Fluoride exposure from infant formula and child IQ in a Canadian birth cohort. Till C, Green R, Flora D, Hornung R, Martinez-Mier EA, Blazer M, Farmus L, Ayotte P, Muckle G, Lanphear B. Environ Int. 2020 Jan;134:105315. doi: 10.1016/j.envint.2019.105315. Epub 2019 Nov 16. PMID: 31743803 Free PMC article.

3. A Benchmark Dose Analysis for Maternal Pregnancy Urine-Fluoride and IQ in Children. Grandjean P, Hu H, Till C, Green R, Bashash M, Flora D, Tellez-Rojo MM, Song PXK, Lanphear B, Budtz-Jørgensen E. Risk Anal. 2022 Mar;42(3):439-449. doi: 10.1111/risa.13767. Epub 2021 Jun 8. PMID: 34101876 Free PMC article.

4. Association Between Maternal Fluoride Exposure During Pregnancy and IQ Scores in Offspring in Canada. Green R, Lanphear B, Hornung R, Flora D, Martinez-Mier EA, Neufeld R, Ayotte P, Muckle G, Till C. JAMA Pediatr. 2019 Oct 1;173(10):940-948. doi: 10.1001/jamapediatrics.2019.1729. PMID: 31424532 Free PMC article.

5. A systematic review and meta-analysis of the association between fluoride exposure and neurological disorders. Miranda GHN, Alvarenga MOP, Ferreira MKM, Puty B, Bittencourt LO, Fagundes NCF, Pessan JP, Buzalaf MAR, Lima RR. Sci Rep. 2021 Nov 22;11(1):22659. doi: 10.1038/s41598-021-99688-w. PMID: 34811523 Free PMC article.

6. 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. doi: 10.1289/ehp.1104912. Epub 2012 Jul 20. PMID: 22820538 Free PMC article. Review.

7. Domain-specific effects of prenatal fluoride exposure on child IQ at 4, 5, and 6-12 years in the ELEMENT cohort. Goodman CV, Bashash M, Green R, Song P, Peterson KE, Schnaas L, Mercado-García A, Martínez-Medina S, Hernández-Avila M, MartinezMier A, Téllez-Rojo MM, Hu H, Till C. Environ Res. 2022 Aug;211:112993. doi: 10.1016/j.envres.2022.112993. Epub 2022 Mar 9. PMID: 35276192 Free PMC article.

8. Association between low fluoride exposure and children's intelligence: a meta-analysis relevant to community water fluoridation. Kumar JV, Moss ME, Liu H, Fisher-Owens S. Public Health. 2023 Jun;219:73-84. doi: 10.1016/j.puhe.2023.03.011. Epub 2023 Apr 28. PMID: 37120936

9. Association of Dental Fluorosis and Urinary Fluoride with Intelligence among Schoolchildren. Lin YY, Hsu WY, Yen CE, Hu SW. Children (Basel). 2023 May 31;10(6):987. doi: 10.3390/children10060987. PMID: 37371219 Free PMC article.

10. Assessment of Fluoride Content in Water and Its Impact on the Intelligence Quotient of School Children Aged 12-13 Years. Kaur D, Kaur K, Sharma A, Goyal H, Pahuja A, Solanki D. Cureus. 2022 Oct 10;14(10):e30157. doi: 10.7759/cureus.30157. eCollection 2022 Oct. PMID: 36397910 Free PMC article.

11. Fluoride exposure and intelligence in school-age children: evidence from different windows of exposure susceptibility. Xu K, An N, Huang H, Duan L, Ma J, Ding J, He T, Zhu J, Li Z, Cheng X, Zhou G, Ba Y. BMC Public Health. 2020 Nov 4;20(1):1657. doi: 10.1186/s12889-020-09765-4. PMID: 33148225 Free PMC article. Retracted.

12. Prenatal fluoride exposure and attention deficit hyperactivity disorder (ADHD) symptoms in children at 6-12 years of age in Mexico City. Bashash M, Marchand M, Hu H, Till C, Martinez-Mier EA, Sanchez BN, Basu N, Peterson KE, Green R, Schnaas L, Mercado-García A, Hernández-Avila M, Téllez-Rojo MM. Environ Int. 2018 Dec;121(Pt 1):658-666. doi: 10.1016/j.envint.2018.09.017. Epub 2018 Oct 10. PMID: 30316181

13. A case study of neurodevelopmental risks from combined exposures to lead, methyl-mercury, inorganic arsenic, polychlorinated biphenyls, polybrominated diphenyl ethers and fluoride. Sprong C, Te Biesebeek JD, Chatterjee M, Wolterink G, van den Brand A, Blaznik U, Christodoulou D, Crépet A, Hamborg Jensen B, Sokolić D, Rauscher-Gabernig E, Ruprich J, Kortenkamp A, van Klaveren J. Int J Hyg Environ Health. 2023 Jun;251:114167. doi: 10.1016/j.ijheh.2023.114167. Epub 2023 May 5.

14. Community Water Fluoridation Exposure: A Review of Neurological and Cognitive Effects [Internet]. [No authors listed] Ottawa (ON): Canadian Agency for Drugs and Technologies in Health; 2019 Oct 23. PMID: 31873994 Free Books & Documents. Review.

15. Community Water Fluoridation Exposure: A Review of Neurological and Cognitive Effects – A 2020 Update [Internet]. [No authors listed] Ottawa (ON): Canadian Agency for Drugs and Technologies in Health; 2020 Nov 4. PMID: 33600099 Free Books & Documents. Review.

16. Effect of fluoridated water on intelligence in 10-12-year-old school children. Aravind A, Dhanya RS, Narayan A, Sam G, Adarsh VJ, Kiran M. J Int Soc Prev Community Dent. 2016 Dec;6(Suppl 3):S237-S242. doi: 10.4103/2231-0762.197204. PMID: 28217543 Free PMC article.

17. Does fluoride exposure affect thyroid function? A systematic review and dose-response meta-analysis. Iamandii I, De Pasquale L, Giannone ME, Veneri F, Generali L, Consolo U, Birnbaum LS, Castenmiller J, Halldorsson TI, Filippini T, Vinceti M. Environ Res. 2024 Feb 1;242:117759. doi: 10.1016/j.envres.2023.117759. Epub 2023 Nov 28. PMID: 38029816 Review.

18. Thyroid function, intelligence, and low-moderate fluoride exposure among Chinese school-age children. Wang M, Liu L, Li H, Li Y, Liu H, Hou C, Zeng Q, Li P, Zhao Q, Dong L, Zhou G, Yu X, Liu L, Guan Q, Zhang S, Wang A. Environ Int. 2020 Jan;134:105229. doi: 10.1016/j.envint.2019.105229. Epub 2019 Nov 4. PMID: 31698198

19. A Scoping Review of Iodine and Fluoride in Pregnancy in Relation to Maternal Thyroid Function and Offspring Neurodevelopment. Griebel-Thompson AK, Sands S, Chollet-Hinton L, Christifano D, Sullivan DK, Hull H, Carlson SE. Adv Nutr. 2023 Mar;14(2):317-338. doi: 10.1016/j.advnut.2023.01.003. Epub 2023 Feb 1. PMID: 36796438 Free PMC article. Review.

20. Fluoride Exposure in Early Life as the Possible Root Cause of Disease In Later Life. Nakamoto T, Rawls HR. J Clin Pediatr Dent. 2018;42(5):325-330. doi: 10.17796/1053-4625-42.5.1. Epub 2018 May 15. PMID: 29763350 Review.

21. Effects of Excess Fluoride and Iodide on Thyroid Function and Morphology. Jiang Y, Guo X, Sun Q, Shan Z, Teng W. Biol Trace Elem Res. 2016 Apr;170(2):382-9. doi: 10.1007/s12011-015-0479-0. Epub 2015 Aug 29. PMID: 26319807

22. Conventional and advanced detection approaches of fluoride in water: a review. Khatkar R, Nagpal S. Environ Monit Assess. 2023 Jan 24;195(2):325. doi: 10.1007/s10661-022-10888-x. PMID: 36692796 Review.

23. Denser but Not Stronger? Fluoride-Induced Bone Growth and Increased Risk of Hip Fractures. Nicole W. Environ Health Perspect. 2021 Jul;129(7):74001. doi: 10.1289/EHP9533. Epub 2021 Jul 12. PMID: 34251877 Free PMC article.

24. Fluoride in Drinking Water, Diet, and Urine in Relation to Bone Mineral Density and Fracture Incidence in Postmenopausal Women. Helte E, Donat Vargas C, Kippler M, Wolk A, Michaëlsson K, Åkesson A. Environ Health Perspect. 2021 Apr;129(4):47005. doi: 10.1289/EHP7404. Epub 2021 Apr 6. PMID: 33822648 Free PMC article.

25. Non-endemic skeletal fluorosis: Causes and associated secondary hyperparathyroidism (case report and literature review). Cook FJ, Seagrove-Guffey M, Mumm S, Veis DJ, McAlister WH, Bijanki VN, Wenkert D, Whyte MP. Bone. 2021 Apr;145:115839. doi: 10.1016/j.bone.2021.115839. Epub 2021 Jan 6. PMID: 33418099 Free PMC article. Review.

26. The Association between Community Water Fluoridation and Bone Diseases: A Natural Experiment in Cheongju, Korea. Lee N, Kang S, Lee W, Hwang SS. Int J Environ Res Public Health. 2020 Dec 9;17(24):9170. doi: 10.3390/ijerph17249170. PMID: 33316869 Free PMC article.

The Facts

• The amount of cavities worldwide, even after water fluoridation and fluoride treatments has NOT decreased in relation to fluoride use. The WHO data since the 1970’s: “Although the prevalence of cavities has declined, the majority of worldwide communities not fluoridating, or those that never adopted fluoridation, have also experienced a reduction in cavities exceeding 75%.”

• 97% of Western Europe has rejected water fluoridation.

• FDA has poison warnings on all fluoride toothpastes.

• FDA states fluoride is a drug, not a nutrient.

• Fluoride is a known enzyme disruptor.

• Fluoride anti-cavity activity depends on calcium and magnesium content in enamel.

• National Academy of Sciences: Fluoride decreases thyroid function.

• Increase in fluoride exposure contributes to hypothyroidism.

• Harvard meta-analysis: Children ingesting higher levels of fluoride tested and average 7 lower IQ points.

• Fluoride is NOT essential in growth and development.

• Fluoride is an unwanted by-product of aluminum, fertilizer and iron ore manufacture.

• The amount of fluoride in water systems cannot be measured accurately- only an estimate.

• In order to remove fluoride from water, a reverse-osmosis system is required.

We are all on the same side-we all want there to be less cavities in teeth and improved dental health. Unfortunately research and experience is showing fluoride is not the answer we all hoped it would be.

Thankfully there is emerging evidence and research supporting new products like hydroxyapatite (the mineral teeth are actually made of). These products are as, if not more effective than fluoride at preventing tooth decay, without sacrificing our health. So lets NOT use that “F” word anymore!