TOPLINE:

Children exposed to water with recommended levels of fluoride demonstrated modestly better cognitive performance in secondary school than those never exposed to sufficient fluoride. However, the cognitive advantage may lessen by age 60 years.

METHODOLOGY:

• Researchers in the US analyzed data from the nationally representative High School and Beyond cohort, which included 58,270 sophomores and seniors at more than 1000 American high schools in 1980.
• The investigators grouped participants by their estimated exposure to fluoride from conception through secondary school, based on municipal water fluoridation practices and naturally occurring fluoride levels.
• Cognitive performance was measured using standardized tests in mathematics, reading comprehension, and vocabulary during 12th grade, with follow-up cognitive assessments conducted at age 60 years.
• The researchers adjusted for factors such as family socioeconomic background, demographics, urbanicity, and region.

TAKEAWAY:

• Students exposed to sufficient fluoride levels throughout childhood or during part of childhood performed better on all measures of adolescent cognitive performance, with estimated effects of approximately 7% of a standard deviation in magnitude.
• Cognitive functioning at age 60 tended to be better in the fluoride-exposed groups, but these associations were not statistically significant.
• Although other studies have found exposure to high levels of fluoride might reduce intelligence quotient, sparking debate about whether any risks from the mineral outweigh its cavity-prevention benefits, such levels are not typically encountered in the US, according to the authors.

IN PRACTICE:

“We find robust evidence that young people who are exposed to typical, recommended levels of fluoride in drinking water perform better on tests of mathematics, reading, and vocabulary achievement in secondary school than their peers who were never exposed to sufficient levels of fluoride,” the researchers reported.

SOURCE:

John Robert Warren, PhD, with the University of Minnesota in Minneapolis, was the corresponding author for the study. It was published online on November 19 in Science Advances.

LIMITATIONS:

Fluoride might causally influence academic performance through “improved oral health or other mechanisms,” but it is also possible that unmeasured differences between the students or communities could explain the association, the authors noted. The researchers had incomplete information about where participants lived, so their location was based on where they went to secondary school. In addition, the study relied on water chemistry data as a proxy for actual fluoride consumption.

DISCLOSURES:

The researchers received support from grants from the National Institutes of Health and Alzheimer’s Association. One author declared having ties to companies that develop screening tools and treatments for dementia.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.