Initial Observations on the Prenatal Fluoride Exposure Study
A new study published by Environmental Health Perspectives (EHP) reports data from Mexico showing an association between higher fluoride urine levels among pregnant women and lower cognitive function among their offspring. This study is a welcome addition to scientific inquiry on the effects of fluoride.
Using mother-child pairs, the study, Prenatal Fluoride Exposure and Cognitive Outcomes in Children at 4 and 6–12 Years of Age in Mexico, analyzed prenatal fluoride urine levels and tracked intelligence test measures of children at ages 4 and 6-12.
It is important to understand what this study tells us and what it does not, since complex studies such as this can be easily misrepresented and sensationalized. This is the first of several planned blog posts to provide information and clarification on this research.
Implications for Community Water Fluoridation
- Most American adults get fluoride from fluoridated drinking water and toothpaste. Fluoride delivery systems are quite different in Mexico, where salt fluoridation is prevalent and fluoride occurs naturally—at a variety of levels—in water supplies. Mothers using both fluoridated salt and consuming drinking water with naturally high levels of fluoride would have had a fluoride intake much higher than those in the U.S.
- This study was not designed to look at fluoride specifically, but instead reported on what was observed in the process of studying several environmental exposures. The study design did not allow researchers to know either the sources or quantity of fluoride intake by study participants.
- Because conditions are not comparable and information on maternal fluoride intake is not known, it would be inappropriate to view this study as a reason to change policies regarding the practice of community water fluoridation in the U.S.
- Scientific evidence is derived from an entire body of research, of which this study represents a single contribution. Howard Hu, the study’s lead author, cautioned that this is “just one study.” Hu told CNN: “It needs to be reproduced in other populations by other scientists.”
- In other work, a 2015 study conducted in New Zealand found “no clear differences in IQ because of fluoride exposure” in the context of community water fluoridation programs. Ongoing inquiry contributes to our breadth of knowledge.
- The American Congress of Obstetricians and Gynecologists (ACOG) and the American Dental Association (ADA) recommend that pregnant women drink fluoridated water in the Oral Health Consensus Statement.
The Campaign for Dental Health, along with the American Dental Association and others, encourages research to ensure that the benefits of community water fluoridation outweigh any potential risks. Based on the total weight of all scientific evidence, we stand behind our support of community water fluoridation as a safe and effective practice to prevent tooth decay and promote oral health.