Till C, Green R, Flora D, Hornung R, Martinez-Mier EA, Blazer M, et al. Fluoride exposure from infant formula and child IQ in a Canadian birth cohort. Environ Int 2020;134:105315.
Among otherwise normal preschool children, what is the association between fluoridated water used to constitute formula as infants/toddlers and IQ?
Multicenter, prospective study drawn from participants in the Maternal-Infant Research on Environmental Chemicals (MIREC) program.
6 cities across Canada.
398 mother-child dyads, the children of which were 3-4 years old.
Wechsler Primary and Preschool Scale of Intelligence-III.
38% of the dyads lived in cities with fluoridated water. An increase of 0.5 mg/L in water fluoride concentration corresponded to a 9.3- and 6.2-point decrement in Performance IQ among both formula-fed (95% CI: −13.77 to −4.76) and breast-fed children (95% CI: −10.45 to −1.94), respectively.
Ingestion of formula constituted from fluoridated water is associated with Performance IQ deficits.
Overall, these studies inform the ongoing debate over the benefits vs risks associated with the fluoridation of water. Clearly, more research is needed. Meanwhile, since the beneficial effects of fluoride predominantly occur at the tooth surface after teeth have erupted, whereas fluoride is not essential for growth and development, a cautious step could be avoidance of fluoridated products and water by women during pregnancy and by infants during the first 6 months of life.
Fluoride exposure during fetal development and intellectual abilities in a Canadian birth cohort.
JAMA Pediatr. 2019; 173: 940-948
Prenatal fluoride exposure and cognitive outcomes in children at 4 and 6-12 years of age in Mexico.
Environ Health Perspect. 2017; 125: 097017
Prenatal fluoride exposure and attention deficit hyperactivity disorder (ADHD) symptoms in children at 6-12 years of age in Mexico City.
Environ Int. 2018; 121: 658-666
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