In a previous blog I talked about how serious and widespread the problem of dental fluorosis is in Canada and how it is being ignored by Health Canada.
Recall that dental fluorosis is irreversible ‘scarring’ of the permanent teeth causing children to be self-conscious and costing families thousands of dollars to repair (see photo).
It would be best to prevent dental fluorosis in the first place.
The main cause of dental fluorosis
Dental fluorosis occurs because infants ingest too much fluoride from birth to age three years when their bodies are small. Fluoride can come from any or all of the following (1,2):
- infant formula made with fluoridated tap water
- early use and ingestion of fluoridated toothpaste
- any fluoride supplementation (pills, lozenges, vitamins, drops)
Remember it is the TOTAL ingestion that places a child at risk. The sources are additive. Fluoride from one source might cause very mild fluorosis but when another source is added, not only does the prevalence (the percentage of kids with fluorosis) increase, so does the severity.
Don’t let ANY public health person blame toothpaste alone. That’s like a doctor blaming lung cancer on a patient because he lives in a polluted city, while ignoring the fact that he’s a 2-pack-a-day smoker.
Is fluoride added to water a drug?
Health Canada is very specific in terms of its definition of what is a drug. (3)
“According to the Food and Drug Act, a drug includes any substance or mixture of substances manufactured, sold or represented for use in:
- the diagnosis, treatment, mitigation or prevention of a disease, disorder, abnormal physical state, or the symptoms thereof in man or animal
- restoring, correcting or modifying organic functions in man or animal, or
- disinfection in premises in which food is manufactured, prepared or kept”
All doctors (family physicians, pediatricians, dentists and pediatric dentists) know they have to adjust the dosage of drugs for children (due to smaller body mass). Babies, especially, should not receive adult doses of drugs. This is essential to avoid unnecessary and sometimes very serious side effects.
Therefore, pediatric drugs are all administered by adjusting the dosage according to the weight of the child.
For example, a dentist or pediatrician might prescribe the following for an oral infection in a baby:
[<3 mo] Dose: 20-30 mg/kg/day by mouth divided into two doses per day. Max: 30 mg/kg/day. (4)
Every drug has a therapeutic window of effectiveness that should be balanced with the risk of any negative side effects if too much drug is administered and/or metabolized.
Fluoride’s (topical) effectiveness against dental decay has declined over the years. Ingestion of fluoride has no benefit. It might still be effective (e.g. in very high concentrations in toothpaste) but only topically, when it bathes the teeth after they erupt into the oral cavity. It is the ingested fluoride that causes unwanted side effects such as permanent tooth damage (dental fluorosis).
So, what do authorities recommend as safe levels for fluoride intake during those critical years of tooth development (birth to age three years)? The maximum fluoride ingestion to avoid dental fluorosis, as has been adopted by the Canadian Dental Association (5), is as follows:
“the total daily fluoride intake from all sources should not exceed 0.05-0.07 mg F / kg body weight in order to minimize the risk of dental fluorosis.”
Has a pediatrician ever asked about the fluoride intake at home by any member of your family? Has your dentist ever calculated, on your behalf, the estimated total intake of fluoride of your child?
If you wanted to protect your baby from too much fluoride intake, how would you go about determining the fluoride content of his/her diet?
If you are feeding your baby exclusively infant formula and making it up with fluoridated tap water, your baby is likely already past the maximum recommended fluoride intake and will likely end up with some fluorosis on the permanent teeth.
Here’s a simple calculation (we’ll use fluoridated water at 1.0 ppm since not all communities have lowered their fluoride levels to 0.7 ppm, as recently recommended by the US EPA and Health Canada).
Fluoridated tap water at 1.0 ppm = 1 mg fluoride/liter
Some babies have a fluid intake as high as 1 L/day (6). A baby at 3 mo. weighing 5 kg (7) could consume 1 L liquid formula in one day. (8)
The calculation for total fluoride intake per day is, therefore, (1 L X 1.0 mg fluoride/L ) /5 kg = 0.2 mg fluoride/kg/day
This is clearly 3 to 4 times the maximum fluoride intake recommended to avoid dental fluorosis. Moms who exclusively breastfeed their babies do not expose their babies to this high level of fluoride because breast milk is almost completely lacking in fluoride
In fact many studies, including ours (9, 10) have shown that breastfeeding reduces the risk for dental fluorosis in children.
This being the case why doesn’t Health Canada issue warnings to moms, who don’t breast feed, that using fluoridated tap water to make formula can cause dental fluorosis in their babies?
The US state of New Hampshire recently passed legislation (11) that requires cities in the state to add the following warning to their water bills.
“Your public water supply is fluoridated. According to the Centers for Disease Control and Prevention, if your child under the age of 6 months is exclusively consuming infant formula reconstituted with fluoridated water, there may be an increased chance of dental fluorosis. Consult your child’s health care provider for more information.”
However, Health Canada has not taken ANY step to warn mothers of this problem and continues to insist that artificial fluoridation causes no harm.
What about weaning babies and introducing foods?
Suppose you either breastfed your baby, or made efforts to avoid fluoridated water to make up infant formula, but now you have to introduce solid foods to your baby’s diet. Will your child still be susceptible to fluorosis?
The short answer is yes, especially if fluoridated water is used to reconstitute foods and beverages and to cook with.
How much fluoride will be introduced in foods used when you start weaning your baby off exclusive milk feeding?
An easy guide is provided by Zohoori et al (12). Any beverage or food made or cooked with fluoridated water will end up with the same amount of fluoride contained in the volume of water used to cook: cereals and vegetables cooked in 1 ppm fluoridated tap will have 1 ppm or more fluoride. These authors recommend that parents be educated about the added fluoride intake in their children.
“Therefore, it is important that parents receive appropriate information on the F [fluoride] content of infant foods and drinks as well as guidelines regarding appropriate waters suitable for the preparation of infant food and drinks.”
Take home message for the reader: Health Canada is failing to do its job. It should warn against using fluoridated tap water to reconstitute infant formula. It should require fluoride labeling on prepackaged and reconstituted foods. Families have to learn on their own how to protect their newborns from developing dental fluorosis.
Challenge to the reader: Talk to your local municipal council representative. Let him/her know Health Canada is not protecting its citizens. Remind him/her that it is the municipality that is responsible for drinking water and council members have the power to stop water fluoridation.
- Brothwell D, Limeback H. Breastfeeding is protective against dental fluorosis in a nonfluoridated rural area of Ontario, Canada. J Hum Lact. 2003 Nov;19(4):386-90.
- Brothwell DJ, Limeback H. Fluorosis risk in grade 2 students residing in a rural area with widely varying natural fluoride. Community Dent Oral Epidemiol. 1999 Apr;27(2):130-6.
- Zohoori FV, Moynihan PJ, Omid N, Abuhaloob L, Maguire A. Impact of water fluoride concentration on the fluoride content of infant foods and drinks requiring preparation with liquids before feeding. Community Dent Oral Epidemiol. 2012 Oct;40(5):432-40.