Wed Jan 08 03:00:17 UTC 2025: ## Controversial Study Links Fluoride in Water to Lower IQ in Children, Sparking Debate

**Washington, D.C. – January 8, 2025** – A new study published in JAMA Pediatrics has reignited the debate surrounding the safety of water fluoridation, linking higher fluoride exposure levels to lower IQ scores in children. The research, conducted by the National Institute of Environmental Health Sciences (NIEHS), analyzed 74 studies from 10 countries and found a statistically significant association between increased urinary fluoride levels and decreased IQ. The study estimates a 1.63-point IQ drop for every 1 mg/L increase in urinary fluoride.

While the neurotoxicity of fluoride at high doses is established, the study suggests potential risks even below the World Health Organization’s safety limit of 1.5 mg/L. However, the research does not specify a threshold below which risk is negligible, leaving unanswered questions about the safety of the current US guideline of 0.7 mg/L. The authors themselves acknowledge insufficient data to assess the impact of the 0.7 mg/L level on children’s IQ.

The study’s methodology has come under fire. Critics point to the inclusion of 52 low-quality studies and the use of single-point urine samples, arguing these factors compromise the reliability of the findings. Concerns have also been raised about confounding factors, such as coal pollution in some study locations. Steven Levy of the American Dental Association’s national fluoride committee advocates against altering current policies based on the study’s uncertainties.

Conversely, the benefits of water fluoridation are well-documented, having significantly reduced cavities and tooth loss since its introduction in the US in 1945. Proponents argue that fluoridation continues to be crucial in reducing socioeconomic disparities in dental care. However, with the widespread availability of fluoride toothpaste, some question the diminishing returns of water fluoridation. The debate underscores the need for further research to determine optimal fluoride levels and the potential risks to vulnerable communities. The timing of the study’s release is particularly notable, coinciding with the incoming administration of President-elect Donald Trump, whose nominee for Health Secretary, Robert F. Kennedy Jr., is a known opponent of fluoridated water.

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