Study Links Fluoride in Drinking Water to Lower Childhood Cognitive Function

London: A new study from Karolinska Institute in Sweden suggests that fluoride exposure during fetal development or early childhood may negatively impact cognitive function in children. Published in the Environmental Health Perspectives, the study adds to previous research highlighting potential risks associated with fluoride consumption during early life.

Fluoride is naturally present in drinking water, though typically at low levels. In some regions, including the United States, Canada, Chile, Australia, and Ireland, it is added to the municipal water supplies at approximately 0.7 mg per liter to prevent tooth decay. However, the study raises concerns about its potential effects on brain development.

“Our findings support the hypothesis that even relatively low fluoride concentrations can influence early childhood development,” said Maria Kippler, Associate Professor at the Institute of Environmental Medicine, Karolinska Institute. She noted that fluoride addition to drinking water remains a debated topic in countries like the US and Canada due to health concerns. 

Researchers analyzed data from 500 mothers and their children in rural Bangladesh, where naturally occurring fluoride levels in water resemble those found in many parts of the world. By measuring fluoride concentrations in urine samples, the study assessed overall exposure from drinking water, food, and dental care products.

Results showed that pregnant women in Bangladesh had a median urinary fluoride concentration of 0.63 mg/L. By the age of ten, children with fluoride levels exceeding 0.72 mg/L in urine exhibited lower cognitive abilities, particularly in verbal reasoning and sensory processing skills.

Dr. Kippler emphasized that while fluoride in toothpaste is essential for dental health, it is not a major exposure source as it is not meant to be ingested. However, she advised caution in ensuring young children do not swallow toothpaste during brushing.

The researchers stressed the need for further evaluation of similar longitudinal studies to determine fluoride’s long-term impact on cognitive development.