Fluoride

What is it?

Fluoride is a binary compound of fluorine and tin.

Fluoride appears to have at least two separate mechanisms by which it prevents tooth decay. It affects the demineralization and remineralization of teeth in a way that makes teeth stronger.¹ Fluoride also reduces the production of acid by oral bacteria, protecting the teeth from damage.² Fluoride appears to have both topical and whole-body effects.³

Fluoride is one of few materials known to stimulate osteoblasts, the cells responsible for building new bone.⁴ While exposure to fluoride clearly causes people to have denser bones, the bone that is formed may not be of optimal quality,⁵ and may not reduce fracture risk significantly.

Where is it found?

Fluoride is a trace mineral found in varying concentrations in foods and in water. Foods high in fluoride include fish, tea, and many different vegetables. Fluoride is added into the municipal water supply of many cities in the United States. For those people without access to fluoridated water, fluoride supplements are available in the forms of tablets and drops. These supplements are not available without a prescription. Many non-prescription dental care products contain fluoride as well, including toothpastes and mouthwashes.

Fluoride has been used in connection with the following conditions (refer to the individual health concern for complete information):

Science Ratings	Health Concerns
	Tooth decay
	Osteoporosis
Reliable and relatively consistent scientific data showing a substantial health benefit. Contradictory, insufficient, or preliminary studies suggesting a health benefit or minimal health benefit. For a herb, supported by traditional use but minimal or no scientific evidence. For a supplement, little scientific support and/or minimal health benefit.

Who is likely to be deficient?

As fluoride is not considered an essential mineral, it does not have an associated deficiency state. Regardless, people living in areas with low concentrations of fluoride in the drinking water do appear to be at a higher risk of significant tooth decay than those living in areas with high amounts of natural or added fluoride.

How much is usually taken?

Drinking water containing 1 mg of fluoride per litre is considered to be roughly the optimal amount for the prevention of tooth decay. For those without access to fluoridated drinking water, chewable fluoride tablets containing 0.25 to 1 mg per day of fluoride or fluoride mouthrinses with 0.05% to 0.2% fluoride content can be used. Liquid fluoride drops are also available.

Are there any side effects or interactions?

The risks associated with fluoridation of the public water supply have been the subject of vigorous and often heated debate since fluoridation began in 1945. Although much research has been done regarding the safety of fluoridation, a recent review found all prior studies to be of sub-optimal quality and far from definitive.⁶

Some,⁷ ⁸ but not all,⁹ ¹⁰ studies have found a correlation between the amount of fluoride intake and increased risk of osteoporotic fractures. The validity of the studies that found increased risk of fracture in communities with fluoridated water has been questioned by some scientists.¹¹ A pooled analysis of 29 studies on this issue concluded that there did not appear to be an increased risk of fracture in areas of water fluoridation.¹²

Dental fluorosis, a brown staining of teeth due to fluoride exposure during childhood, is the best-documented adverse effect of fluoride. At a water fluoride level of 1 part per million (or 1 mg per litre), roughly 13% will have fluorosis to an aesthetically concerning degree.¹³

Some scientists have concluded that water fluoridation is associated with an increased risk of bone tumours,¹⁴ although most others disagree.¹⁵

At the time of writing, there were no well-known drug interactions with fluoride.

References
(To view, roll mouse over heading; to hide, click on heading)

1. Clarkson BH. Caries prevention-fluoride. Adv Dent Res 1991;5:41-5 [review].

2. Marquis RE. Antimicrobial actions of fluoride for oral bacteria. Can J Microbiol 1995;41:955-64 [review].

3. Ellwood KP, Blinkhorn AS, Davies RM. Fluoride: how to maximize the benefits and minimize the risks. Dent Update 1998;25:365-72 [review].

4. Lau KHW, Baylink DJ. Molecular mechanism of action of fluoride on bone cells. J Bone Miner Res 1998;13:1660-7 [review].

5. Evans FG, Wood JL. Mechanical properties and density of bone in a case of severe endemic fluorosis. Acta Orthop Scand 1976;47:489-95.

6. McDonagh MS, Whiting PF, Wilson PM, et al. Systematic review of water fluoridation. BMJ 2000;321:855–9 [review].

7. Kurttio P, Gustavsson N, Vartiainen T, Pekkanen J. Exposure to natural fluoride in well water and hip fracture: a cohort analysis in Finland. Am J Epidemiol 1999;150:817–24.

8. Danielson C, Lyon JL, Egger M, Goodenough GK. Hip fractures and fluoridation in Utah’s elderly population. JAMA 1992;268:746–8.

9. Hiller S, Cooper C, Kellingray S, et al. Fluoride in drinking water and risk of hip fracture in the UK: a case-control study. Lancet 2000;355:265–9.

10. Phipps KR, Orwoll ES, Mason JD, Cauley JA. Community water fluoridation, bone mineral density, and fractures: prospective study of effects of older women. BMJ 2000;321:860–4.

11. Rosen CJ. Fluoride and fracture: an ecological fallacy. Lancet 2000;355:247–8 [editorial].

12. McDonagh MS, Whiting PF, Wilson PM, et al. Systematic review of water fluoridation. BMJ 2000;321:855–9 [review].

13. McDonagh MS, Whiting PF, Wilson PM, et al. Systematic review of water fluoridation. BMJ 2000;321:855–9.[review]

14. Diesendorf M, Colquhoun J, Spittle BJ, et al. New evidence on fluoridation. Aust NZ J Public Health 1997;21:187–90 [review].

15. McDonagh MS, Whiting PF, Wilson PM, et al. Systematic review of water fluoridation. BMJ 2000;321:855–9 [review].

Learn more about Healthnotes, the company.

Learn more about the authors of Healthnotes.

The information presented in Healthnotes is for informational purposes only. It is based on scientific studies (human, animal, or in vitro), clinical experience, or traditional usage as cited in each article. The results reported may not necessarily occur in all individuals. For many of the conditions discussed, treatment with prescription or over the counter medication is also available. Consult your doctor, practitioner, and/or chemist for any health problem and before using any supplements or before making any changes in prescribed medications. Information expires March 2007.

Product Search