Fluoride Action Network | Updated by Ellen Connett | September 3, 2019
As of May 2020, a total of 73 studies have investigated the relationship between fluoride and human intelligence. Of these investigations, 65 studies have found that elevated fluoride exposure is associated with reduced IQ in humans, while over 60 animal studies have found that fluoride exposure impairs the learning and/or memory capacity of animals. The human studies, which are based on IQ examinations of 23,872 children (63 studies) and 245 adults (2 studies), provide compelling evidence that fluoride exposure during the early years of life can damage a child’s developing brain. For a discussion of the 8 studies that did not find an association between fluoride and IQ, click here.