Does fluoride impact neurological development in children?

Although more research is needed to know for sure, it appears that excessive fluoride exposure is linked to poorer cognition in children; it’s important to note that community fluoridation in the United States and Canada is far below this level. A meta-analysis of 8 cross-sectional and cohort studies did not find that fluoride exposure via community water fluoridation affects IQ scores in children. However, high fluoride exposure (3.7 mg/L) from natural groundwater in certain geographical areas (e.g., parts of China and India) was associated with lower IQ when compared with lower fluoride exposure (0.7 mg/L). There was no difference in IQ between mean exposure to 0.9 mg/L fluoride when compared to 0.3 mg/L fluoride.^[1] Another meta-analysis of 26 observational studies mostly conducted in China found that high fluoride exposure from water is associated with lower intelligence compared to normal fluoride exposure.^[2] This data is limited by its observational nature and the presence of various confounding factors. For example, the impact of socio-economic status or exposure to environmental toxins was not able to be controlled.