A recent U.S. government report suggests that fluoride in drinking water at double the recommended limit may be linked to lower IQs in children. While fluoride is known to strengthen teeth and reduce cavities, the report indicates that exposure to higher levels of fluoride might pose neurological risks, particularly for children. This acknowledgment of a potential hazard from fluoride in drinking water is a significant development, as previous studies have not delved into this aspect of fluoride exposure. The report highlights the need for further research to better understand the impact of fluoride on children’s IQ levels.
The report from the National Toxicology Program, a division of the Department of Health and Human Services, analyzed studies from several countries, including China, India, and Mexico, to conclude that fluoride levels above 1.5 milligrams per liter in drinking water are associated with lower IQs in children. The exact decrease in IQ points due to fluoride exposure was not quantified in the report, but some studies suggested a difference of 2 to 5 points in children with higher fluoride exposure. Despite these findings, the report did not explore the effects of lower levels of fluoride or the potential impacts on adults, indicating the need for more comprehensive studies in these areas.
For decades, fluoride has been added to drinking water in the United States to improve oral health and reduce the occurrence of cavities. Federal health officials have recommended a fluoride level of 0.7 milligrams per liter since 2015, down from the previous upper limit of 1.2 milligrams. The World Health Organization has set a safe limit for fluoride in drinking water at 1.5 milligrams per liter. The report raises concerns about the approximately 1.9 million Americans on water systems with naturally high fluoride levels and the need to protect them from potential health risks associated with excessive fluoride exposure.
The history of water fluoridation in the United States dates back to the mid-20th century when Grand Rapids, Michigan became the first city to add fluoride to tap water in 1945. The practice was endorsed by federal officials in 1950 as a preventive measure against tooth decay. While fluoride is naturally present in water and soil, the addition of fluoride to drinking water has been instrumental in improving dental health in the country. However, concerns about fluorosis, a condition that causes discoloration of teeth, have led to a reduction in the recommended fluoride levels in drinking water in recent years.
In addition to promoting dental health, fluoride exposure has been linked to potential risks for brain development, particularly in fetuses and young children. Animal studies have shown that fluoride can affect neurochemistry and cell function in brain regions essential for learning, memory, and behavior. Research conducted by the National Research Council in 2006 and subsequent studies raised questions about the neurological effects of high fluoride exposure. The delay in finalizing the recent report on fluoride and IQ was due to the need to ensure accuracy and reliability in the scientific findings before releasing them to the public.
Given the potential risks associated with high fluoride exposure, particularly for children, researchers and health officials recommend pregnant women to lower their fluoride intake from water and other sources. Policy discussions on mandating fluoride content on beverage labels and considering fluoride limits in drinking water systems may also be necessary to address public health concerns. While the debate on the impact of fluoride on IQ and neurological development continues, further research and studies are essential to understand the full scope of the risks and benefits associated with fluoride exposure in drinking water.
