Fear of fluoride--More bark than bite?

Issue: BCMJ, vol. 48, No. 7, September 2006, Page 323 Council on Health Promotion

Despite numerous studies confirming the benefits and safety of fluoridation, there remains considerable opposition to this important public health measure. In BC only 11% of homes have fluoridated water. Due to unfounded fears about its harmful effects, some communities have stopped water fluoridation and subsequently experienced an increase in incidences of tooth decay. Many patients are concerned about fluoride and there is much misinformation on the topic.[1,2] For those of us in practice, answering patients’ concerns on this issue can be daunting, particularly if we are presented with some of the published “evidence” that fluoride is harmful.

Part of the problem is that there are in fact published reports of harm from fluoride, and occasionally individuals with genuine scientific or medical/dental credentials will make statements opposing fluoridation. This does not mean these claims are true, and one might ask why the vast majority of qualified scientists do not agree with the interpretation of the evidence adopted by the anti-fluoridation camp.[3]

We know that there is no such thing as a free lunch; any measure carries some risks. However, we also know that any time a health measure is studied repetitively, some studies will show false positive or negative results simply because of poor design or just by chance. In addition, many “findings of harm” may be insignificant, inaccurate, or simply taken out of context—a situation similar to the ongoing popular debate about childhood immunizations.

Benefits of water fluoridation

Extensive research done over the past 50 years shows that fluoridation of public water supplies is a safe, effective, and low-cost way to reduce tooth decay and improve dental health for people of all ages.

Studies show that children who drink fluoridated water can expect to have up to 35% less decay than those who drink non-fluoridated water. The strong teeth children develop by using fluoridated water last throughout adult life. As adults, they will have fewer cavities or missing teeth.

Adults who drink fluoridated water can also expect to have less tooth decay.

All patients then, including children, face a greater risk from not having fluoride than from being exposed to the small quantities recommended.

Risks of water fluoridation

At the recommended levels of fluoridation and supplementation (see Resources), the only real (and small) risk is dental fluorosis. This is a mottling of the teeth due to fluoride exposure and is a dose-related condition. At the recommended water levels (0.7–1.2 ppm), at worst, it is a minimal cosmetic problem (white specks on teeth) that can be dealt with easily. Higher levels of fluoride exposure can be associated with brown discoloration or pitting of tooth enamel—neither of which is thought to be a threat to tooth function or longevity. This same fluoride can appear in skeletal bone but has not been proven to cause increased fracture risk.

However, anything taken in excess, even oxygen, is a poison. Acute toxicity from fluoride produces nausea, vomiting, diarrhea, abdominal pain, seizure, cardiac arrhythmias, and coma.[4] These effects only ever occur at levels far in excess of those found in fluoridated water.

More adverse effects?

Since 1950, opponents of fluoridation have claimed that fluoride causes a long list of other problems.[5] These include:

• Cancer

• Down syndrome

• Heart disease

• Osteoporosis

• Bone fractures


• Allergic reactions

• Alzheimer disease

• Low intelligence

There have been numerous studies over that last 50 years and no convincing evidence has been found to support these claims.[4,6]

The bottom line

The addition of fluoride to water supplies or to dental hygiene regimens in recommended doses has repeatedly been proven to be a safe, effective, and cost-saving measure for ensuring good dental health. Patient concerns about fluoride should be acknowledged and addressed in light of the best available evidence.

—Lloyd Oppel, MD
Alternative Health and Therapeutics Committee

Resources on fluoride supplementation

Visit these web sites for information on the facts and misconceptions of fluoride supplementation. American Academy of Family Physicians. 2004 American Academy of Family Practice policy statement on fluoridation of public water supplies.

(This site gives a blow-by-blow analysis and critique of the studies allegedly showing the harm of fluoride.)

Centers for Disease Control and Prevention. Achievements in Public Health, 1900–1999: Fluoridation of Drinking Water to Prevent Dental Caries. www.cdc.gov/mmwr/preview/mmwrhtml/mm4841a1.htm

Quackwatch. Fluoridation: Don’t Let the Poisonmongers Scare You! 

2004 US Preventive Services Task Force. Prevention of Dental Caries in Preschool Children. www.ahrq.gov/clinic/uspstf/uspsdnch.htm

Canadian Pediatric Society. Statement on the use of fluoride in infants and children. 


1. You’re putting WHAT in our Drinking Water? www.suite101.com/article.cfm/chiropractic_health_care/8930 (accessed 9 August 2006).
2. Fluoridation/Fluoride, Toxic Chemicals in your Water. www.holisticmed.com/fluoride/ (accessed 9 August 2006).
3. The Canadian Dental Association, the Canadian Medical Association, the Canadian Public Health Association, the Canadian Pediatric Society, and the World Health Organization (among others).
4. American Academy of Family Physicians. 2004 American Academy of Family Practice policy statement on fluoridation of public water supplies. www.aafp.org/online/en/home/clinical/clinicalrecs/fluoridation.html (accessed 9 August 2006).
5. Hodge HC. Evaluation of some objections to water fluoridation. In: Newbrun E (ed). Fluorides and Dental Caries. 3rd ed. Springfield, Illinois: Charles C. Thomas; 1986:221-255.
6. National Research Council. Health Effects of Ingested Fluoride. Washington, DC: National Academy Press; 1993.

Lloyd Oppel, MD, MHSc, FCFP(Em). Fear of fluoride--More bark than bite?. BCMJ, Vol. 48, No. 7, September, 2006, Page(s) 323 - Council on Health Promotion.

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