Exposure to low concentrations of fluoride in drinking water, particularly during pregnancy or early childhood, may impair children's cognitive development.

Prenatal and childhood exposure to fluoride and cognitive development: findings from the longitudinal MINIMat cohort in rural Bangladesh
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“Given the concern about health risks, the addition of fluoride to drinking water is controversial and has been widely debated in the USA and Canada,” says Maria Kippler, associate professor at the Institute of Environmental Medicine, Karolinska Institutet. “Our results support the hypothesis that even relatively low concentrations of fluoride can impact children’s early development.”
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Water fluoridation is the controlled addition of fluoride to public water supplies to reduce tooth decay. #medindia #water #fluoride’

Water fluoridation is the controlled addition of fluoride to public water supplies to reduce tooth decay. #medindia #water #fluoride’





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Fluoride Exposure in Rural Bangladesh
The researchers followed 500 mothers and their children in rural Bangladesh, where fluoride occurs naturally in the drinking water, to investigate the association between early exposure to fluoride and children’s cognitive abilities. The concentrations are similar to those found in many other countries worldwide.Trained psychologists evaluated the children’s cognitive abilities at five and ten years of age, using well-established tests. The exposure to fluoride in the mothers and children was determined by measuring the concentrations in urine samples, which reflects ongoing exposure to all sources, such as drinking water, food and dental care products.
“I’d like to stress that dental care products such as toothpaste are not normally a significant source of exposure since they are not intended for ingestion,” says Dr. Kippler. “Fluoride in toothpaste is important for prevention of caries, but it’s important to encourage small children not to swallow the toothpaste during brushing.”
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Fluoride Levels in Pregnant Women and Child Cognition
The median concentration of fluoride in urine of the pregnant Bangladeshi women was 0.63 mg/L. Increasing concentrations of fluoride in the pregnant women could be linked to decreasing cognitive abilities in their children at five and ten years of age.Children that had more than 0.72 mg/L fluoride in their urine by the age of ten also had lower cognitive abilities than children with less fluoride in their urine, with most pronounced associations for verbal reasoning skills and the ability to interpret and process sensory input. The exposures that were associated with impaired cognitive development are lower than those obtained at the existing WHO and EU threshold for fluoride in drinking water, which is 1.5 mg/L.
The researchers found no statistically significant link between fluoride concentrations in the urine of the five-year-olds and their cognitive abilities.
“This may be due to the shorter exposure time,” Dr. Kippler speculates, “but also to the fact that urinary fluoride concentrations aren’t as reliable in younger children owing to greater variations in how much fluoride is taken up and stored in the body, particularly in the bones.”
Exploring Molecular Mechanisms Behind Fluoride's Effects
Since it was an observational study, no firm conclusions can be drawn about causalities. It is therefore important to assess the overall results of several similar longitudinal studies, according to the researchers. They will now investigate the associations in other populations and establish experimental models to determine the possible molecular mechanisms driving it.“There is a need for more research to create a robust basis for reviewing fluoride health risks and thresholds for drinking water, foods, and dental care products, especially for children,” she continues. “Even small changes in cognition at a population level can have serious public health consequences.”
Reference:
- Prenatal and childhood exposure to fluoride and cognitive development: findings from the longitudinal MINIMat cohort in rural Bangladesh - (https://ehp.niehs.nih.gov/doi/10.1289/EHP14534)
Source-Eurekalert