Overview
Infants are by far the most susceptible to fluoride toxicity. Due to their small size, infants receive up to four times more fluoride (per kilogram of body weight) than adults consuming the same level of fluoride in water. Not only do infants receive a larger dose, they have an impaired ability to excrete fluoride through their kidneys. Healthy adults can excrete more than 50 per cent of fluoride ingested. Infants, however, normally excrete around 15 to 20 per cent. This results in higher rates of bioaccumulation of fluoride in the body, and may explain why infants fed formula made with fluoridated water suffer higher rates of dental fluorosis during childhood.
A baby’s blood brain barrier is not fully developed at birth, so neurotoxic fluoride has greater access to the brain than as an adult. More than 30 studies have associated elevated fluoride exposure with neurological impairment in children. This may be caused or exacerbated by fluoride’s affect on the thyroid gland. Parents should therefore take precautions to reduce their child’s exposure to fluoride as much as possible.
In 1994, the American Dental Association (ADA), American Academy of Pediatrics (AAP), and American Academy of Pediatric Dentistry (AAPD) reversed their old policy of recommending that doctors prescribe fluoride supplements to newborn infants. While these organizations have refrained from taking the obvious step of recommending that fluoridated water not be be added to infant formula (a practice that exposes infants to nearly 4 times more fluoride than supplements) a growing number of prominent dental researchers have made this recommendation.
Relevant studies
Dietary fluoride intake for fully formula‐fed infants in New Zealand: impact of formula and water fluoride.
Peter Cressey BSc(Hons); Dec. 2010, Journal of Public Health Dentistry.
“The fluoride content of water used to reconstitute infant formulae has a greater impact on fluoride intake of fully formula‐fed infants than the fluoride content of the powdered infant formulae. Infants fully formula‐fed on formulae prepared with optimally fluoridated water (0.7‐1.0mg/L) have a high probability of exceeding the UL for fluoride and are at increased risk of dental fluorosis.”
Timing of fluoride intake in relation to development of fluorosis on maxillary central incisors.
Hong L, Levy SM, et al. (2006). Community Dentistry and Oral Epidemiology.
“[F]luoride intakes during each of the first 4 years were individually significantly related to fluorosis on maxillary central incisors, with the first year most important (P < 0.01), followed by the second (P < 0.01), third (P < 0.01), and fourth year (P = 0.03).”
Associations between Intakes of Fluoride from Beverages during Infancy and Dental Fluorosis of Primary Teeth.
Marshall TA, et al. (2004), Journal of the American College of Nutrition 23:108-16.
“Our data suggest that the fluoride contribution of water used to reconstitute infant feedings is a major determinant of primary tooth fluorosis.”
Breastfeeding is protective against dental fluorosis in a nonfluoridated rural area of Ontario, Canada
SOURCE: Brothwell D, Limeback H. (2003). Journal of Human Lactation 19: 386-90.
“Our results suggest that breastfeeding infants may help to protect against fluorosis. This is consistent with other studies that suggest that consuming infant formula reconstituted with tap water increases the risk for dental fluorosis. Importantly, this study shows that the protective effect of breastfeeding is important not only in fluoridated communities but also in nonfluoridated areas. Parents should therefore be advised that they may be able to protect their children from dental fluorosis by breastfeeding their infant and by extending the duration for which they breastfeed.”
Risk of enamel fluorosis in nonfluoridated and optimally fluoridated populations: considerations for the dental professional.
Pendrys DG. (2000). Journal of the American Dental Association 131(6):746-55.
“The findings of this investigation suggest that nearly 10 percent of the enamel fluorosis cases in optimally fluoridated areas could be explained by having used infant formula in the form of a powdered concentrate during the first year.”
Risk periods in the development of dental fluorosis.
Bardsen A, Bjorvatn K. (1998); Clinical Oral Investigations 2:155-160.
“The findings indicate that early mineralising teeth (central incisors and first molars) are highly susceptible to dental fluorosis if exposed to fluoride from the first and – to a lesser extent – also from the 2nd year of life.”
Risk factors for enamel fluorosis in optimally fluoridated children born after the US manufacturers’ decision to reduce the fluoride concentration of infant formula.
Pendrys DG, Katz RV. (1998). American Journal of Epidemiology 148:967-74.
“There was a strong association between mild-to-moderate fluorosis on later forming enamel surfaces and infant formula use in the form of powdered concentrate (OR=10.77, 95% CI 1.89-61.25).”
The risk of fluorosis in students exposed to a higher than optimal concentration of fluoride in well water.
Ismail AI, Messer JG. (1996). Journal of Public Health Dentistry 56:22-7.
“[T]he odds ratio of fluorosis on enamel zones that began forming during the first year of life was 8.31 (95% CI = 1.84, 38.59) for children exposed since birth or during the first year of life relative to those exposed after 1 year of age. The odds that a child had a maxillary central incisor with fluorosis were 5.69 (95% CI = 1.34, 24.15) times higher if exposure occurred during the first year of life compared with exposure after 1 year of age. Only those exposed to the high-fluoride water during the first year of life developed fluorosis on the mandibular central incisors… The first year of life was a significant period for developing fluorosis on the mandibular and maxillary central incisors.”
Absorption and retention of dietary and supplemental fluoride by infants.
Ekstrand J, et al. (1994). Advances in Dental Research 8:175-80.
“It appears that, at least under some circumstances, high intakes of fluoride during the early months of life may make the difference between developing or failing to develop dental fluorosis. A study conducted in Sweden of 12- and 13-year-old children who had lived since birth in a community with 1.2 ppm of fluoride in the drinking water demonstrated that dental fluorosis was less common in those who had been breast-fed during the first 4 months of life than in those who had been fed powdered formulas reconstituted with tap water (Forsman, 1977). A somewhat similar study in the United States demonstrated that among 7- to 13-year-old children (most of them living in a community with fluoride concentration of the drinking water 1 mg/L), the prevalence of mild enamel fluorosis was significantly greater in those who had been fed concentrated liquid formula diluted with tap water during the first 3 months of life than in those who had been breast-fed during this time (Walton and Messer, 1981). It seems reasonable to conclude that the lower prevalence of fluorosis of the permanent teeth of individuals who were breast-fed during the early months of life is related to the low fluoride concentrations of human milk – concentrations less than 7 ug/L regardless of the concentration of fluoride in the women’s drinking water.”