Potential adverse effects of water fluoride on teeth
This page expands on the fluoride warning published by the Hutt City Council. It includes official Government information, international research information, and the views of FANNZ.
In the belief that it reduces tooth decay, the Hutt City Council adds fluoride to most water supplies in the Hutt Valley. Water fluoridation has been promoted by the New Zealand Government since the 1950s, despite being abandoned or rejected by all continental European nations. Most local bodies in New Zealand do not add fluoride to water.
It has recently been recognized that infant formula reconstituted with fluoridated water poses a risk of harm, with no benefit, to infants. Click here to see detailed information.
What is "fluoride"?
Fluoride occurs naturally in water as calcium fluoride. Food Standards Australia New Zealand confirms that fluoride is not a nutrient and not an essential mineral. There is no minimum required daily intake for fluoride. Therefore, medically speaking, you cannot have "too little fluoride". Research has established that pre-European settlement Maori had almost perfect teeth, despite drinking low fluoride water. Fluoride is not necessary for dental health, although surface application such as toothpaste can harden the enamel. It is internationally recognised that swallowing fluoridated water, as opposed to surface application, has little if any protective effect against tooth decay.
The fluoridating agent used in fluoridation does not occur naturally. It is over 80 times more biologically active, and more toxic, than calcium fluoride. It is a partially refined industrial waste product, containing heavy metal contaminants, scrubbed from chimney stacks in superphosphate plants. It is illegal to discharge it into the atmosphere or environment.
The levels of natural fluoride in New Zealand are often below 0.1 mg/L, a level generally considered safe for most people (although some subgroups will suffer adverse effects even at this level). The highest natural level in NZ is 0.3 m/L. Artificial fluoridation increases fluoride content to 0.7 - 1.2 mg/L. This is too high for use in infant formula.
The infant formula risk
U.S. research has found that the use of fluoridated water in preparing infant formula heightens the risk of enamel fluorosis, particularly for children under the age of 1 (and up to the age of 4). Enamel fluorosis can range from an almost imperceptible tooth-staining to brittleness in both baby teeth and later adult teeth. It is the first outward sign of fluoride poisoning.
The American Dental Association (ADA) and the US Centers for Disease Control and Prevention (CDC) have both issued advice that fluoridated water should not be used to prepare infant formula, or given to infants by any other means. The ADA and CDC confirm that “the problem is the fluoridated water itself, not the levels infant formula”.
Recent studies cited in the report of the National Research Council, "Fluoride in Drinking Water: A Scientific Review of EPA’s Standards," have raised the possibility that infants could receive a greater than optimal amount of fluoride through liquid concentrate or powdered baby formula that has been mixed with fluoridated water containing fluoride during a time that their developing teeth may be susceptible to enamel fluorosis. This occurs on baby and permanent teeth while they are forming under the gums.
If liquid concentrate or powdered infant formula is the primary source of nutrition and tap water is fluoridated or has substantial natural fluoride (0.7 mg/L or higher), it may pose an increased risk of dental fluorosis, and parents may consider using water that is fluoride free or contains low levels of fluoride to reduce the risk of fluorosis. Examples are water that is labeled purified, demineralized, deionized, distilled or reverse osmosis filtered water.
The occasional use of water containing optimal levels of fluoride should not appreciably increase a child’s risk for fluorosis.
The report (ANZFA P93) on which the New Zealand standard (2.9.1) was based confirms the ADA’s advice – that both fluoridated water on its own, and any formula made up with it, pose an increased risk of dental fluorosis.
The latest international research confirms that it is exposure to fluoride during the first year of life that poses the greatest risk of developing dental fluorosis in both the baby teeth and permanent teeth, and that the following 3 years present measurable but decreasing risk.
In New Zealand, research in both the 1980s and 2006 (the latter quoted by the Ministry of Health) shows that between one in three and one in four children, in areas with a fluoridated supply, have some fluorosis. Between 3% and 5% of fluorosis is in the more serious categories.
What is Enamel (Dental) Fluorosis?
Dental fluorosis is a deformity in the tooth enamel caused by excessive fluoride intake while the tooth enamel is forming. It ranges from small white flecking in mild forms to dark brown or black mottling in more severe forms. In its more severe forms the enamel is brittle and crumbles, requiring ongoing costly dental treatment. In its mild forms it may be aesthetically disturbing and cause self-consciousness or embarrassment similar to that of a child having crooked teeth.
More importantly, the UK Medical Research Council and the US National Research Council recognise dental fluorosis as “the first outward sign of chronic fluoride poisoning.”
How to avoid this risk to your children
There are a number of ways to reduce the concentration of fluoride in water and the risk of fluorosis from the infant formula, as identified on the Hutt City Coucnil web site.
Purified bottled water is not generally available. Domestic filters that remove fluoride can be purchased if this is found more convenient than collecting unfluoridated water from the Petone fountain. Reverse osmosis and fluoride-specific ion-exchange filters, or distillation, are the three ways of reducing fluoride to less than 0.1 mg/L.
Boiling water does not reduce the fluoride content. If anything it will increase the concentration in the water.
Breast milk contains extremely low levels of fluoride even if the mother drinks fluoridated water and does not pose a risk of fluorosis. Health authorities recommend breast feeding as the best option for infants.
Hutt City Council commissioned a report on infant formula reconstituted with fluoridated water. The report writer admitted that it was biased, putting only the Ministry of Health view, and no independent authorities were approached for input. Information released under Official Information legislation revealed that this was in part “ghost written” by Government Health officials. Hutt City Council has rejected the recommendation of this biased report by, responsibly in our view, providing the infant formula warning information on it web site.
Links:American Dental Association
Centers for Disease Control and Prevention