A comprehensive review published in JAMA Pediatrics on January 6, has reignited the debate over fluoride’s potential effects on children’s cognitive development. The study, conducted by researchers at the National Toxicology Program, found a significant association between higher fluoride exposure and lower IQ scores in children.
The meta-analysis, which examined 74 studies from 10 countries, revealed that children exposed to higher levels of fluoride had lower IQ scores compared to those with lower exposure. Specifically, the researchers found that for every 1 mg/L increase in urinary fluoride, there was a decrease of 1.63 IQ points in children.
Key findings from the study
- A 7-point average IQ difference between children with the highest and lowest fluoride exposures.
- A statistically significant IQ decrease in communities with fluoride levels above 2 mg/L in drinking water.
- The association persisted even when focusing on studies with a low risk of bias.
However, the study’s authors noted important caveats.
- Most studies were conducted outside the United States, where fluoride levels in water are often higher.
- There was insufficient data to determine if the U.S. recommended fluoride level of 0.7 mg/L in drinking water affects children’s IQ.
- The review did not establish a direct cause-and-effect relationship
What is fluoride?
One of the natural minerals is fluoride. As per the National Institute of Dental and Craniofacial Research, its concentration varies depending on the location and can be found in soil, air, food, and water sources worldwide. By hardening the enamel, or outer layer, of teeth, fluoride makes them stronger. Dental professionals frequently use it as an ingredient in toothpastes, mouth rinses, and varnishes for dental hygiene and teeth cleaning.
Why is fluoride added to drinking water?
According to the American Dental Association, fluoride is a “safe, beneficial, and cost-effective” public health measure that can reduce cavities in adults and children by 25%.
The findings of the study have sparked concern among some experts. Dr. Bruce Lanphear, a health sciences professor at Simon Fraser University, emphasized the need for an urgent scientific panel to review the evidence. “A 5-point decrease in a population’s IQ would nearly double the number of people classified as intellectually disabled,” Lanphear and his team of scholars conclude.
On the other hand, pediatric dentists worry that these results could negatively impact public health. Dr. Erica Caffrey, chair of the American Academy of Pediatric Dentistry’s Council on Clinical Affairs, pointed out that areas where fluoride has been removed have seen dramatic increases in decay rates.
Source: RFK Jr. X account, November 2024.
The debate is likely to intensify, especially given that Robert F. Kennedy Jr., the nominee for Secretary of Health and Human Services, has previously expressed opposition to water fluoridation.
