Major Study Confirms Fluoride in Drinking Water Does Not Affect IQ or Brain Function

A groundbreaking study has found no link between fluoride in drinking water and negative impacts on brain health, including IQ and cognitive function. Published on April 13 in the Proceedings of the National Academy of Sciences (PNAS), the research analyzed data from more than 10,000 participants over several decades.

The study, led by Rob Warren, PhD, a sociologist and population health expert at the University of Minnesota, used data from the Wisconsin Longitudinal Study. This long-term study tracked individuals who graduated high school in 1957, measuring their IQ at age 16 and cognitive abilities at ages 53, 64, 72, and 80.

Key findings include:

• No evidence that community water fluoridation negatively affects adolescent IQ or adult cognitive functioning.
• No difference in cognitive outcomes between individuals exposed to fluoridated water and those who were not.
• Contrasts with claims by HHS Secretary Robert F. Kennedy Jr., who announced in April that the CDC would revise its long-standing recommendation on water fluoridation.

The study’s authors stated:

“We find no evidence that [community water fluoridation] is negatively associated with adolescent IQ or adult cognitive functioning.”

Expert Reactions: Fluoride Remains Safe and Beneficial

Scott Tomar, DMD, a spokesperson for the American Dental Association and professor at the University of Illinois Chicago, emphasized the importance of the findings in addressing misinformation.

“Despite misinformation that is out there, the best available evidence indicates that community water fluoridation has no effect on IQ, cognition, or other measures of neurodevelopment.”

Danelle Fisher, MD, a pediatrician at Providence Saint John’s Health Center in Santa Monica, CA, also supported the study’s conclusions.

“They reassure us that the use of fluoride in proper amounts does not have any definitive effects on IQ. It makes a good case for having fluoride in our drinking water.”

Context: Fluoride’s Role in Public Health

Fluoride in drinking water has been a cornerstone of public health policy in the U.S. for decades, primarily due to its proven effectiveness in preventing tooth decay and cavities. The CDC and other health organizations have long recommended fluoridation as a safe and cost-effective way to improve dental health, which is directly linked to overall well-being.

The new study’s findings align with this established consensus, providing further evidence that fluoridation does not pose risks to cognitive health. The research also addresses concerns raised by recent studies conducted in regions with fluoride levels higher than those permitted in the U.S., such as China, which have suggested potential links to lower IQ.