A woman’s higher fluoride levels during pregnancy are associated with some ADHD symptoms in school-aged children, according to researchers at the University of Toronto, York University and other universities.
The study, published in the journal International Environment, analyzed data from 213 mother-child pairs in the city of Mexico. The monitoring started in 1994 and continued until 2005.
“Our findings are consistent with a growing body of evidence suggesting that the developing fetal nervous system can be adversely affected by higher levels of fluoride exposure,” said Morteza Bashash, lead author of the study.
Tap water and dental products have been fluorinated in Canadian and US communities (also milk and table salt in some other countries) with varying amounts for more than 60 years to prevent caries. In recent years, there has been a keen debate on fluoridation of water and whether this is safe for children’s developing brains.
The research team analyzed urine samples from mothers during their pregnancy and from children aged 6-12 to measure fluoride exposure in both mothers and children. It then correlated fluoride levels in the urine with the performance of children in a variety of tests and questionnaires that measure inattention and hyperactivity.
The analysis took into account other factors known to affect the development of the nervous system such as pregnancy, pregnancy, birth weight, gender, smoking history, lead exposure, etc.
“Our findings show that children with elevated prenatal fluoride exposure were more likely to experience ADHD symptoms as reported by their parents. Exposure to prenatal fluoride has been more closely related to inconsiderate behaviors and cognitive problems, but not to overactivity, “said Bashash.
ADHD is the most common disorder in childhood, affecting over 5% of school-age children. Symptoms often persist in adulthood and can affect everyday life. Researchers are trying to understand the causes of ADHD in order to initiate preventive strategies for risk mitigation.