Flawed Fluoride Study Sparks Misinformation: Experts Defend Community Water Fluoridation
The recently published MADRES study in JAMA Network Open examined the potential association between maternal urinary fluoride levels and behavioral outcomes in their 3-year-old children, focusing on a small cohort of predominantly Latino pregnant individuals in Los Angeles. Despite the study’s findings suggesting a link between prenatal fluoride exposure and child behavioral issues, significant methodological limitations and a limited sample size have led to concerns about the misrepresentation of fluoride’s impacts.
In contrast to the MADRES study, a 2023 study conducted in Australia explored the relationship between fluoridated water exposure and the executive function and emotional and behavioral development of 5-year-old children, finding no such association. The Australian study’s higher quality results are attributed to its avoidance of the unreliable modified ultrafiltration method for measuring individual fluoride exposure and its analysis of a significantly larger sample of 2,682 children, compared to the 229 children in the MADRES study.
Experts have raised concerns regarding the MADRES study, particularly noting that spot samples of urinary fluoride are not a valid measure of an individual’s fluoride exposure. Additionally, the reliability of the children’s IQ measurements was questioned. Despite these acknowledged limitations, major news organizations, including the Los Angeles Times, NBC, and the New York Times, have picked up the MADRES study, potentially spreading misinformation to healthcare providers and the public.
Critics such as Howard Pollick, BDS, MPH, a professor at the University of California, San Francisco, School of Dentistry, emphasize that the study’s results do not justify changes to recommendations on the beneficial use of fluoride for preventing dental problems. Pollick points out that eight out of 12 measures of mother-reported behaviors in the study were not statistically significant.
In response to the MADRES study, organizations, such as the American Fluoridation Society, American Dental Association (ADA), and American Academy of Pediatrics, have issued statements highlighting the study’s limitations. They reaffirm the safety and efficacy of community water fluoridation in preventing dental disease, supported by evidence from trusted sources such as the United States Centers for Disease Control and Prevention and systematic reviews by the Community Preventive Services Task Force.
Oral health professionals are encouraged to consider the adequacy of data sets, the significance of the study’s scope, and the proper measurement of contributing factors when reviewing new research. Trusted resources, including printable guides and FAQs from the ADA, are available to support discussions about the importance of fluoridation within the practice team and with patients. Properly designed research remains essential for informing sound policies, clinical decisions, and trusted dialogues between the healthcare community and the public.
