Study finds that fluoride in drinking water can impair cognition in children

A recent study has found that exposure to fluoride during the foetal stage or early childhood can impair cognitive abilities in children. The study was conducted by researchers from the Karolinska Institutet in Sweden and published in the journal Environmental Health Perspectives. 

The study supports some previous studies that indicate that exposure to fluoride during the foetal stage or early childhood is not good for kids. High concentrations of fluoride can occur in well water and in some countries, it is added to drinking water to counteract caries in the population.

Fluoride occurs naturally as fluoride ions in drinking water but the concentrations are generally low in public water supplies. In some countries, such as the US, Canada, Chile, Australia and Ireland, fluoride is commonly added to the municipal water supply at around 0.7 mg per litre to prevent caries.

Dr Maria Kippler, associate professor at the Institute of Environmental Medicine, Karolinska Institutet said, "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.

"Our results



support the hypothesis that even relatively low concentrations of fluoride can impact children’s early development."

For the study, the researchers followed 500 mothers and their children in rural Bangladesh where fluoride occurs naturally in the drinking water to understand the link between early exposure to fluoride and children’s cognitive abilities. The concentrations are similar to those found in many other countries worldwide.

Dr Kippler said, "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."

Fluoride in toothpaste is important for the prevention of caries but it’s important to encourage small children not to swallow the toothpaste during brushing.

The median concentration of fluoride in the urine of the pregnant Bangladeshi women was 0.63 mg/L. Children who 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 the most pronounced associations for verbal reasoning skills and the ability to interpret and process sensory input.