Overview
- Published in Science Advances on November 19, the study analyzes the nationally representative High School and Beyond cohort of 58,270 students tested in 1980, with a 2021 follow-up of 26,820 participants around age 60.
- Exposure to recommended fluoride levels was associated with modestly better 12th‑grade performance in mathematics, reading, and vocabulary, with effects around 7% of a standard deviation.
- No statistically significant association was found between childhood fluoride exposure at recommended levels and cognitive functioning at age 60.
- Researchers inferred childhood exposure from municipal fluoridation records and USGS well data, using high school location as a proxy for residence, which introduces potential misclassification and unmeasured confounding.
- Very high fluoride levels linked to lower IQ in prior meta-analyses are uncommon in the United States, and authors say the results support continued municipal fluoridation while calling for targeted studies to test causal pathways such as improved oral health.