Overview
- Researchers reporting Monday in PNAS found no link between community water fluoridation at U.S. levels and lower teen IQ or weaker thinking skills later in life.
- The analysis followed 10,317 Wisconsin high school graduates from 1957 with IQ at age 16 and cognitive testing again at ages 53, 64, 72, and 80.
- Exposure was estimated from when local systems began fluoridating and from well locations rather than from urine or blood, which experts note leaves prenatal and infant windows unmeasured.
- The recommended U.S. level is 0.7 milligrams per liter, which is far below levels in many international studies that reported IQ associations.
- Even as the CDC, the American Dental Association, and the American Academy of Pediatrics endorse fluoridation for cutting tooth decay by about 25%, Utah and Florida banned it in 2025 and other states are weighing similar bills.