A recent pilot study conducted by Tulane University has found a potential link between long-term consumption of drinking water with high levels of fluoride and cognitive impairments in children. Published in the journal Neurotoxicology and Teratology, the study was conducted in rural Ethiopia, where farming communities rely on wells with varying fluoride levels ranging from 0.4 to 15.5 mg/L, well above the World Health Organization’s recommended fluoride levels of below 1.5 mg/L.
To assess cognitive abilities, researchers recruited 74 school-aged children and evaluated their skill in drawing familiar objects, such as a donkey or a house. The children were scored based on any missing details in their drawings. In addition, a standard computerized memory test, which is unaffected by language or culture, was used to further measure cognitive ability.
The study revealed that higher exposure to fluoride in drinking water was correlated with more errors on the drawing and memory tests. Although the causal relationship between fluoride exposure and neurotoxicity remains uncertain, lead author Tewodros Godebo, Assistant Professor of Environmental Health Sciences at Tulane University School of Public Health and Tropical Medicine, hopes that these preliminary findings will encourage further research into the potential cognitive impacts of fluoride exposure.
Fluoride is known to be essential for preventing tooth decay. However, excessive intake of fluoride has been associated with lower IQs in previous epidemiological studies conducted in rural communities in China and India. Moreover, animal research has shown that fluoride can cross the placenta and blood-brain barriers. In regions where alternative water sources are scarce, this could potentially result in chronic excessive fluoride exposure starting from conception.
It is estimated that over 200 million people worldwide are exposed to high levels of fluoride in their drinking water. The Ethiopian Rift Valley, where this study was conducted, provides an ideal research area for investigating potential impacts, as individuals raised in the area have consistent exposure to naturally occurring fluoride and share similar lifestyles with surrounding villages, thus minimizing the influence of confounding factors.
Godebo intends to replicate the results in Ethiopia by studying a larger cohort of children and analyzing the cognition of children in low-fluoride Ethiopian communities for signs of potential cognitive impact. He emphasizes the importance of conducting such studies to determine the safety and risks associated with water fluoridation in drinking water supply systems, both for the general public and government agencies.
The study’s co-authors include Nati Pham and Arti Shankar from Tulane University, Marc Jeuland from Duke University, Amy Wolfe from the University of Kentucky, and Redda Tekle-Haimanot and Biniyam Alemayehu from Addis Ababa University.
1. Source: Coherent Market Insights, Public sources, Desk research
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