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.
Question
Among otherwise normal preschool children, what is the association between fluoridated water used to constitute formula as infants/toddlers and IQ?
Design
Multicenter, prospective study drawn from participants in the Maternal-Infant Research on Environmental Chemicals (MIREC) program.
Setting
6 cities across Canada.
Participants
398 mother-child dyads, the children of which were 3-4 years old.
Intervention
Wechsler Primary and Preschool Scale of Intelligence-III.
Outcomes
IQ score.
Main Results
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.
Conclusions
Ingestion of formula constituted from fluoridated water is associated with Performance IQ deficits.
Commentary
,
,
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.
References
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Fluoride exposure during fetal development and intellectual abilities in a Canadian birth cohort.
JAMA Pediatr. 2019; 173: 940-948
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Prenatal fluoride exposure and cognitive outcomes in children at 4 and 6-12 years of age in Mexico.
Environ Health Perspect. 2017; 125: 097017
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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
Article Info
Identification
Copyright
© 2020 Published by Elsevier Inc.