Study raises questions about fluoride and children’s IQ
A
study of young children in Canada suggests those whose mothers drank
fluoridated tap water while pregnant had slightly lower IQ scores than
children whose mothers lived in non-fluoridated cities. But don’t dash
for the nearest bottled water yet. Health experts at the American
Academy of Pediatrics and the American Dental Association cautioned that
public policy and drinking water consumption should not change on the
basis of this study.
“I still stand by the
weight of the best available evidence, from 70 years of study, that
community water fluoridation is safe and effective,” said Brittany
Seymour, a dentist and spokeswoman for the American Dental Association. “If
we’re able to replicate findings and continue to see outcomes, that
would compel us to revisit our recommendation. We’re just not there
yet.”
The American Academy of Pediatrics, likewise, recommends fluoride
in toothpastes and tooth varnishes for children because the mineral
prevents tooth decay. In drinking water, “fluoridation has been
incredibly protective,” said Aparna Bole,
a pediatrician who chairs the Council on Environmental Health at the
American Academy of Pediatrics. Fluoridation reduces the prevalence of
cavities by about one-fourth, according to the Centers for Disease Control and Prevention. The CDC considers water fluoridation one of the 10 top health achievements of the past century, on par with vaccines and antismoking campaigns.
Bole
called the new study, published Monday in JAMA Pediatrics, “an
important addition to our body of knowledge. It supports the public
health community’s ongoing reevaluation of optimal fluoridation levels
in drinking water.”
In January 1945, researchers added fluoride to municipal water in Grand Rapids, Mich., the first program
to enlist fluoride to protect a city’s teeth. Opponents of fluoridation
have since raised concerns both ludicrous — fluoridation is not a communist plot — and legitimate, such as fluorosis.
In the mild form of fluorosis, faint white streaks appear on the teeth
of young children. Severe fluorosis, which is much rarer, damages bones.
Dozens
of cities in the United States and Canada, such as Portland, Ore., and
Vancouver, do not add fluoride to city water. Elsewhere in the United
States, fluoridation is the norm. As of 2014, per CDC data, two-thirds of people in the United States
had fluoride in their drinking water. In 2015, to reduce the risk of
mild fluorosis, the Department of Health and Human Services cut its
fluoride recommendations almost in half, from 1.2 milligrams per liter to 0.7 milligrams per liter.
Few
older studies addressed potential risks, or the lack thereof,
associated with fluoride exposure during pregnancy, said study author Christine Till,
a neuropsychologist at Toronto’s York University. She added that
“whether we found an effect or not, the data would be really relevant
because we would then address that gap in our knowledge.”