Fluoride
What is Fluoride?
Fluoride is a mineral that can be found in the soil, water, and air. It can be found in food in very low amounts.
Fluoride is a mineral that helps protect our teeth from dental caries and supports healthy bone mineralization. The most concentrated sources of fluoride are drinking water and toothpaste.
Some studies have shown that fluoride and aluminum can exacerbate symptoms of ASD by worsening excitotoxicity and inflammation, and excess fluoride may affect cognitive development in children.
Fluoride is added into the public supply of drinking water in most areas. Almost all water contains some fluoride; however, there is not enough fluoride in the water to prevent tooth decay [1].
Tooth decay can be caused by certain bacteria in the mouth. When a person eats a lot of sugar or carbohydrates, the bacteria start to produce a type of acid that removes minerals (like calcium or phosphorus) from the surface of the tooth. Fluoride helps to remineralize the tooth surface, which helps teeth to stay strong and smooth and prevents cavities from forming.
Half of the fluoride that is taken in by mouth is absorbed from the gastrointestinal tract after 30 minutes. Once the fluoride is in the bloodstream it enters mineralized tissue (bones and teeth) [2].
It’s an ongoing discussion if fluoride is neurotoxic for children or not. Extremely high levels of fluoride are known to cause neurotoxicity in adults, and negative impacts on memory and learning have been reported in rodent studies, but little is known about the substance’s impact on children’s neurodevelopment. [6]
In a meta-analysis, researchers from Harvard School of Public Health (HSPH) and China Medical University in Shenyang for the first time combined 27 studies and found strong indications that fluoride may adversely affect cognitive development in children. [7]
Based on the findings, the authors say that this risk should not be ignored and that more research on fluoride’s impact on the developing brain is warranted. [7]
Have you ever been told to skip the fluoride at the dentist? This is why! It is 100% YOUR decision if you decide to pass on fluoride, just be sure you do your research before choosing your stance and discuss your preferences with your child’s dentist.
Top Sources of Fluoride
Fluoridated water
Toothpaste
Infant formulas
Some foods may contain trace levels of fluoride including coffee, shrimp, oatmeal, raisins, and others.
Fluoride Alternatives
Trying to Avoid Fluoride? Consider the Following:
Fluoride-free toothpaste
Our favorite is RiseWell, which contains naturally-derived hydroxyapatite, a mineral that makes up 97% of our tooth enamel and 60% of your bones and has been proven to strengthen and protect your teeth without fluoride.
Check out Risewe’ll’s Kids Products here! Use code ASDDIETITIAN10 for 10% off all Risewell products
You can also find other toothpastes that are fluoride-free in your typical grocery store or health food store. Look for brands like Tom’s of Maine, Schmidt’s, and hello. Always read the label to ensure they are a fluoride-free product as many brands offer both fluoride-free and floride-containing products!
Use a high-quality filter like AquaTru that removes fluoride from the water (AquaTru removes more than 90% fluoride from the water without an additional filter)
Berkey can also filter fluoride, but you have to buy an additional fluoride filter
Recommended Intake
These recommendations are based on the Recommended Dietary Allowance (RDA), which is the average daily level of intake sufficient to meet the nutrient recommendations of nearly all (97-98%) of healthy individuals.
Males
1-3 years: 0.7 mg/day
4-8 years: 1.0 mg/day
9-13 years: 2 mg/day
14-18 years: 3 mg/day
19-50 years: 4 mg/day
51+ years: 4 mg/day
Females
1-3 years: 0.7 mg/day
4-8 years: 1.0 mg/day
9-13 years: 2 mg/day
14-18 years: 3 mg/day
19-50 years: 3 mg/day
51+ years: 3 mg/day
Deficiency
Common symptoms of fluoride deficiency include:
Dental Caries
Brittle Bones
Individuals at risk for fluoride deficiency include:
Individuals living in areas where the public water supply does not have enough or any fluoride at all.
Toxicity
The Tolerable Upper Intake Level (UL) is the maximum daily intake unlikely to cause adverse health effects.
Males and Females
1-3 years: 1.3 mg/day
4-8 years: 2.2 mg/day
9-13 years: 10 mg/day
14-18 years: 10 mg/day
19-50 years: 10 mg/day
51+ years: 10 mg/day
Symptoms of Fluoride Toxicity
White spots on teeth
Dental Caries
Calcification of tendons and ligaments in the body. [3]
See the Research section below for more on neurodevelopmental disorders and excess fluoride
Supplements
The main form of fluoride that is found in dietary supplements is sodium fluoride, which is only given as a supplement if a primary care physician or dentist finds the individual at high risk for cavities. Supplements are available only with a prescription. The supplements are only intended for children living in areas where the fluoride concentration in the water is low. When sodium fluoride is taken with water, absorption of it in the gastrointestinal tract is almost 100%. If it is taken with milk, baby formula, or foods with high concentrations of calcium, absorption in the gastrointestinal tract may be reduced by 10 to 25%.
DISCLAIMER: Before starting any supplement or medication, always consult with your healthcare provider to ensure it is a good fit for your child. Dosage can vary based on age, weight, gender, and current diet.
Fluoride & Autism in the Research
Fluoride & Autism Risk
Fluoride and aluminum can emphasize pathological problems by worsening toxicity and inflammation, but fluoride is rarely looked at as the cause for ASD [4].
There has been a high ASD prevalence from countries where the water supply is fluoridated as well as from areas where there are reports of fluorosis [5].
Neurodevelopmental Disabilities with Elevated Fluoride Levels
It’s an ongoing discussion if fluoride is neurotoxic for children or not. Extremely high levels of fluoride are known to cause neurotoxicity in adults, and negative impacts on memory and learning have been reported in rodent studies, but little is known about the substance’s impact on children’s neurodevelopment. [6]
In a meta-analysis, researchers from Harvard School of Public Health (HSPH) and China Medical University in Shenyang for the first time combined 27 studies and found strong indications that fluoride may adversely affect cognitive development in children. [7]
Based on the findings, the authors say that this risk should not be ignored and that more research on fluoride’s impact on the developing brain is warranted. [7]
The recent epidemiological results support the notion that elevated fluoride intake during early development can result in IQ deficits that may be considerable. Recognition of neurotoxic risks is necessary when determining the safety of fluoride-contaminated drinking water and fluoride uses for preventive dentistry purposes. [8]
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[1] Cdc.gov. 2021. About Fluoride | FAQs | Community Water Fluoridation | Division of Oral Health | CDC. [online] Available at: <https://www.cdc.gov/fluoridation/faqs/about-fluoride.html> [Accessed 9 February 2021].
[2] Cdc.gov. 2021. About Fluoride | FAQs | Community Water Fluoridation | Division of Oral Health | CDC. [online] Available at: <https://www.cdc.gov/fluoridation/faqs/about-fluoride.html> [Accessed 9 February 2021].
[3] Who.int. 2021. Inadequate or excess fluoride. [online] Available at: <https://www.who.int/teams/environment-climate-change-and-health/chemical-safety-and-health/health-impacts/chemicals/inadequate-or-excess-fluoride> [Accessed 9 February 2021].
[4] Strunecka A, Strunecky O. Chronic Fluoride Exposure and the Risk of Autism Spectrum Disorder. Int J Environ Res Public Health. 2019;16(18):3431. Published 2019 Sep 16. doi:10.3390/ijerph16183431
[5] Strunecka A, Blaylock RL, Patocka J, Strunecky O. Immunoexcitotoxicity as the central mechanism of etiopathology and treatment of autism spectrum disorders: A possible role of fluoride and aluminum [published correction appears in Surg Neurol Int. 2018 May 08;9:98]. Surg Neurol Int. 2018;9:74. Published 2018 Apr 9. doi:10.4103/sni.sni_407_17
[6] Impact of fluoride on neurological development in children. Harvard School of Public Health. 2012. https://www.hsph.harvard.edu/news/features/fluoride-childrens-health-grandjean-choi/
[7] Choi AL, Sun G, Zhang Y, Grandjean P. Developmental fluoride neurotoxicity: a systematic review and meta-analysis. Environ Health Perspect. 2012 Oct;120(10):1362-8. doi: 10.1289/ehp.1104912. Epub 2012 Jul 20. PMID: 22820538; PMCID: PMC3491930.
[8] Grandjean P. Developmental fluoride neurotoxicity: an updated review. Environ Health. 2019 Dec 19;18(1):110. doi: 10.1186/s12940-019-0551-x. PMID: 31856837; PMCID: PMC6923889.
Authors
Sheila Nguyen, Dietetic Intern
Suzy Morris, Dietetic Intern
Brittyn Coleman, MS, RDN/LD, CLT
