Almost all dentists would agree that fluoride is an essential part of dental health. In fact, the practice of water fluoridation has been taking place since 1945 in an effort to prevent tooth decay. Even though some skeptical dental health experts would dispute the fact that orally ingested fluoride has any real benefits; lets assume that it does for arguments sake. The real issue at hand becomes how much daily fluoride is too much? Scientific evidence supports 1mg/day intake as being associated with maximum anti-cavity effect with the minimal chance of fluorosis (fluoride toxicity) (1). According to the Canadian Dental Association, the adequate and safe amount varies based on body weight. The problem is that everybody has a different body mass so the amount needed can vary greatly. We get fluoride in our drinking water, toothpaste and even mouthwash. The amount of fluoride that you can receive from brushing your teeth daily is approximately 2mg using a “pea-sized” amounts of toothpaste (1). Drinking fluoridated water, soft drinks and juice can add another 1-3mg depending on the amount of fluid consumed (2). Multiple sources of fluoride can easily raise exposure well above safe levels, especially in children.
Children are the most vulnerable group to fluorine overdose because of their small size and developing organs and tissues. They are being exposed to fluoride topically through brushing their teeth, rinsing with mouthwash and also orally consumed through water sources. Fluorosis is excess fluoride intake that causes the disruption of proper enamel formation. This causes unsightly mottling and pitting of the teeth, enamel striations, and in severe cases, chalky-white teeth (1). Cosmetic treatment is required to correct these deformities. A study in Toronto, Ontario found that 13% of children, aged 7-13 had moderate fluorosis (3). The question that begs to be answered is what is this doing to our children on a systemic level?
Understanding the mechanism that fluoride works to prevent cavities sheds light on what whether water fluoridation is the safest way to improve dental health. Fluoride is thought to prevent tooth decay by having an anti-bacterial effect (1). This is a topical mechanism, which takes place on the surface of teeth. There is also some evidence suggesting that fluoride uptake makes developing teeth in children less likely to decay by making the enamel more acid resistant (1). This is the rationale behind systemic ingestion of fluoride. However, systemic intake also predisposes all of the body to the potential harmful effect of fluoride. If the primary anti-cavity effect comes from topical application (from toothpaste and mouth wash) then drinking fluoride will have little benefits and possibly cause harm. There now is emerging evidence that even if it may reduce the chance of cavities, ingested fluoride have lasting harmful effects on a child’s neuro-development (4).
The recent buzz about fluoride was caused by a study published by researchers from Harvard University. The authors set out to evaluate the effects of fluoride on the neurological health of children. They stated, “Although fluoride may cause neurotoxicity in animal models and acute fluoride poisoning causes neurotoxicity in adults, very little is known of its effects on children’s neurodevelopment.” They found the children in high fluoride areas had significantly lower IQ than those who lived in low fluoride areas (4). Fluoride exposure to the developing brain, which is much more susceptible to injury caused by toxins and chemicals than is the adult brain, may possibly lead to permanent damage (4). Fluoride easily crosses the placenta and very high levels have been found in baby formula compared to breast milk (5). New Hampshire is the first state to issue a warning about mixing infant formula with fluoridated water. The results found in the Harvard university study (and others before it) seriously call into question the safety of fluoridation, which has been accepted as normal practice for over half a century.
The cumulative effects of increased fluoride exposure throughout childhood and into the adult years are difficult to assess but the prospect is a more frightening problem. Studies show that 50% of all ingested fluoride remains stored in bones for many years. Skeletal fluorosis is well documented in the scientific literature as increasing the risk of hip fractures and bone deformities (6). Another study, published earlier in 2012, linked fluoride with cardiovascular disease and artery calcification. This is very troubling since cardiovascular disease is the number one killer in North America and what we drink everyday can be contributing to it. After looking deeper into the research surprisingly fluoride has been linked to many other diseases including thyroid disease and infertility.
Diving into the safety of fluoride has really turned out to be an eye opening experience. Not only is the benefit water fluoridation questionable, the negative health effects are piling up. The bottom line is that there may be a case for topical application of fluoride to prevent cavities but drinking fluoridated water is dangerous and not effective. Even if ingesting fluoride reduces tooth decay, the negative health effects on developing brains and bones far outweigh and benefits. Reducing sugar intake and maintaining adequate vitamin D levels are a much more effective, not to mention safer, approach to maintaining dental health.
Many of you are wondering on how you can remove fluoride from your drinking water. Unfortunately most commercial water filtration systems do not remove fluoride. This includes charcoal filters like Brita. To be sure, check with your manufacturer. Also, beware of fluorine present in bottled water, juices and soft drinks. The only way to remove fluoride from your water is to use reverse osmosis or an alumina filtration system. Look for bottled water with no fluorine content. Also consider using un-fluoridated toothpaste to reduce your exposure. A good strategy, if you want to still get the topical fluoride, is to alternate between fluoridated and non-fluoridated toothpaste each day; using one in the morning and the other in the evening. I hope you have a better understanding of a mineral that you are probably ingesting everyday. Try to reduce your exposure to maximize the health of your families now and in the future.
1) J Godel; Canadian Paediatric Society. The use of fluoride in infants and children. Nutrition and Gastroenterology Committee. Paediatr Child Health 2002;7(8):569-72
2) Recommendations for Using Fluoride to Prevent and Control Dental Caries in the United States http://www.cdc.gov/mmwr/preview/mmwrhtml/rr5014a1.htm Accessed Aug 7, 2012.
3) Leake J, Goettler F, Stahl-Quinlan B, Stewart H. Has the level of fluorosis among Toronto children changed? J Can Dent Assoc 2002;68:21-5
4) Choi AL, Sun G, Zhang Y, Grandjean P 2012. Developmental Fluoride Neurotoxicity: A Systematic Review and Meta-Analysis. Environ Health Perspect. July 20 2012
5) New Hampshire passes first state-wide fluoride warning law. http://www.fluoridealert.org/United-States/New-Hampshire/New-Hampshire-passes-first-state-wide-fluoride-war.aspx Accessed August 8 2012.
6) Danielson, C. Hip fractures and fluoridation in Utah’s elderly population, JAMA. 1992; 268(6): 746-748.
7) Li Y, Berenji GR, Shaba WF, Tafti B, Yevdayev E, Dadparvar S. Association of vascular fluoride uptake with vascular calcification and coronary artery disease. Nucl Med Commun. 2012 Jan;33(1):14-20.