If any one of you has ever done a little research online regarding fluoride and hypothyroidism- you know that the debate around fluoride is REAL. I for one was very interested in this topic as I grew up being told fluoride was not harmful and very important for my oral health. I became accustomed to using fluoride toothpaste and chose a basic water filter that reduced some toxins but did not filter out Fluoride (for those that are wondering it was a Brita filter).
However, once I was diagnosed with hypothyroidism and started my own journey to wellness I came across a lot of information suggesting that it is best to avoid fluoride as much as possible as it may reduce thyroid function. That said, I did not want to compromise my oral health and I am sure many of you are in the same boat.
So here’s what you need to know:
1. Fluoride does help prevent tooth decay…but particularly in children and babies.
The Cochrane Review, conducted in 2015, looked at 20 studies on the effects of fluoridated water on tooth decay and 135 studies on dental fluorosis revealed that fluoridation is effective at reducing levels of tooth decay among children. The introduction of water fluoridation resulted in children having 35% fewer decayed, missing and filled baby teeth and 26% fewer decayed, missing and filled permanent teeth.
It is interesting to note that the evidence was strong for baby teeth, not necessarily permanent adult teeth.
2. Fluoride has been linked to multiple adverse health effects.
Another recent study published in 2014 concluded that, “the available evidence suggests that fluoride has a potential to cause major adverse human health problems, while having only a modest dental cavities prevention effect”.
These adverse effects of fluoride include
Reduced cognitive development in children with high exposure to fluoride
Hypothyroidism when exposed to high levels
There have also been a number of studies that link fluoride and cancer. More than 50 population-based studies which have examined the potential link between water fluoride levels and cancer have been reported in the medical literature.
Fluoride can interact with a wide range of enzyme-mediated cellular processes in the body when exposed to toxic levels
3. The harmful effects on the thyroid appear to be dependent on the amount of exposure
Just like most adverse reactions, the more you are exposed to a potentially harmful substance, the higher the risk for harm. The same is true with fluoride and the thyroid. High amounts of fluoride has been linked to reduced thyroid function including reduced production of T3 and T4 hormones. Harmful effects appear to be more prevalent in iodine deficient individuals (iodine seems to help protect the thyroid from the adverse effects of fluoride).
It is interesting to note that high amounts of fluoride was previously a treatment for hyperthyroidism as the substance was known to slow the thyroid down.
4. If you drink a lot of water, you are exposed to more fluoride
Back in 1991, the Centers for Disease Control (CDC) 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 six-fold variation just from water consumption of water alone.
After combing through all the research, I realized that I was actually potentially exposing myself to A LOT of fluoride. As I mentioned, I brushed my teeth with fluoride and I am drink approximately 3-5L of water a day, depending on my activity level.
Personally, I have now chosen to filter the fluoride out of my water at home. I still brush with fluoridated toothpaste on occasion, but I choose natural toothpaste more often. To keep up with oral hygiene I rinse my mouth with warm water and sea salt, brush and floss at least twice a day and visit the hygienist multiple times a year.
What is your experience with fluoride? Do you avoid it? I would love to hear from you! Leave your comments below!
Dr. Emily
Works Cited
Iheozor-Ejiofor Z, Worthington HV, Walsh T, O'Malley L, Clarkson JE, Macey R, Alam R, Tugwell P, Welch V, Glenny A. Water fluoridation for the prevention of dental caries. Cochrane Database of Systematic Reviews 2015, Issue 6. Art. No.: CD010856. DOI: 10.1002/14651858.CD010856.pub2
Peckham S, Awofeso N. Water Fluoridation: A Critical Review of the Physiological Effects of Ingested Fluoride as a Public Health Intervention. The Scientific World Journal. 2014;2014:293019. doi:10.1155/2014/293019.
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
Molecular mechanisms of fluoride toxicity. Barbier O, Arreola-Mendoza L, Del Razo LM Chem Biol Interact. 2010 Nov 5; 188(2):319-33
Public Health Services US. Review of Fluoride Benefits and Risks. Table 11, p. 17, 1991, http://www.fluoridation.com/fluoride.html
J Epidemiol Community Health. 2015 Feb 24. pii: jech-2014-204971
Indian J Endocrinol Metab. 2011 Jul; 15(Suppl2): S113–S116