New study from USC-Keck School of Medicine
Fluoride exposure during pregnancy has been linked to an increased risk of childhood behavioral problems, according to research published today by the Keck School of Medicine of USC.
Researchers at the university conducted the first U.S.-based study examining the link between prenatal fluoride and childhood social, emotional and behavioral functioning.
Nearly three-quarters of Americans consume drinking water that contains fluoride, a practice that began in 1945 to help prevent tooth decay, according to researchers.
The findings appear in JAMA Network Open, a medical journal published by the American Medical Association.
The study analyzed more than 220 mother-child pairs, collecting data on fluoride levels during pregnancy and child behavior at age 3. The researchers found that a 0.68 milligram per liter increase in fluoride exposure was associated with nearly double the chance of a child showing neurobehavioral problems in a range considered close to or at a level to meet the criteria for clinical diagnosis.
“Women with higher fluoride exposure levels in their bodies during pregnancy tended to rate their 3-year-old children higher on overall neurobehavioral problems and internalizing symptoms, including emotional reactivity, anxiety and somatic complaints,'' said Tracy Bastain, an associate professor of clinical population and public health sciences at the Keck School of Medicine.
The findings add to existing evidence from animal studies showing that fluoride can harm neurodevelopment, as well as data from studies conducted in Canada, Mexico and other countries showing that prenatal exposure to fluoride is linked with a lower IQ in early childhood, according to the study.
The researchers said they hope the new findings help convey the risks of fluoride consumption during pregnancy to policymakers, health care providers and the public.
“Our findings are noteworthy, given that the women in this study were exposed to pretty low levels of fluoride -- levels that are typical of those living in fluoridated regions within North America,'' said Ashley Malin, an assistant professor of epidemiology at the University of Florida's College of Public Health and Health Professions and College of Medicine.
Malin conducted the research in part as a postdoctoral scholar at the Keck School of Medicine.
Tracking emotions and behavior data for the study came from the Maternal and Developmental Risks from Environmental and Social Stressors (MADRES) Center for Environmental Health Disparities at the Keck School of Medicine. MADRES follows predominantly Hispanic families in Los Angeles from pregnancy throughout childhood.
“The overall goal of MADRES is reducing the effects of environmental contaminants on the health and well-being of marginalized communities,'' said Bastain, who co-directs MADRES.
Currently, no official recommendations exist for limiting fluoride consumption during pregnancy. However, the researchers hope the findings can help stimulate change.
“There are no known benefits to the fetus from ingesting fluoride,'' Malin said. “And yet now we have several studies conducted in North America suggesting that there may be a pretty significant risk to the developing brain during that time.''
