Prenatal exposure to higher levels of fluoride not only impairs
cognitive development but also significantly increases the
incidence of attention-deficit/hyperactivity disorder (ADHD) in
children, new research shows.
Our current study suggests that fluoride not only interferes
with overall IQ or overall cognitive development but may also
contribute to symptoms of ADHD, lead investigator Morteza Bashash,
PhD, Dalla Lana School of Public Health, University of Toronto,
Canada, told Medscape Medical News.
This isnt the first study linking fluoride to childhood ADHD or
cognitive impairment. But, said Bashash, it is the first to find an
increased incidence of ADHD with prenatal fluoride exposure.
This work builds off of previous research I and
my team published on this population demonstrating that higher
levels of urine fluoride during pregnancy are associated with lower
scores on tests of cognition and IQ in these school-age children,
The study was
published online October 10 in Environment
Previous animal studies as well as clinical studies have raised
concerns over potential effects of fluoride exposure on
neurobehavioral development, such as lower IQ and attention
deficits, the investigators note.
To examine the association between prenatal exposure and
symptoms associated with ADHD, the researchers analyzed data on 213
mother-child pairs from the Early Life Exposures to Environmental
Toxicants (ELEMENT) birth cohort study. The study recruited
pregnant women from 1994 to 2005 and continues to follow these
women and children.
The research team used maternal urinary samples and child
assessments of ADHD-like behaviors at ages 6 to 12 years.
They measured urinary fluoride levels adjusted for creatinine
(MUFcr) in spot urine samples collected during pregnancy.
Child assessments consisted of both the Conners Rating
ScalesRevised (CRS-R), which was completed by mothers, and the
Conners Continuous Performance Test (CPT-II), which was
administered to the children.
Data were adjusted for factors known to affect neurodevelopment,
including lead exposure, smoking history, gestational age at birth,
maternal marital status, age at delivery, and socioeconomic
The investigators found that the mean MUFcr was 0.85?mg/L
(SD?=?0.33). The difference between the first and third quartiles,
or interquartile range (IQR), was 0...