From the Guidelines
Fluoride in drinking water at recommended levels does not cause brain damage, but excessive exposure to high levels of fluoride has been associated with reduced intelligence in children. The use of fluoride in drinking water is a widely debated topic, with some studies suggesting potential negative effects on neurological development, particularly in children exposed to high levels of fluoride 1. According to the espen micronutrient guideline published in Clinical Nutrition in 2022 1, fluoride can be safely consumed up to 4 mg/day in men and 3 mg/day in women, and fluoridation programs aim to bring fluoride levels up to a range preventing or minimizing tooth decay by 26-44% in children, teenagers, and adults. Key points to consider include:
- The need for fluoridation remains debated 1
- Fluoride might have an impact on children's neurological development, with a meta-analysis showing a significant association between high levels of fluoride in water and reduced levels of intelligence in children 1
- Artificial water fluoridation should be reconsidered globally, according to some authors 1
- The clinical course of systemic toxicity from ingested fluoride begins with gastric signs and symptoms and can develop with alarming rapidity 1 However, it is essential to note that the concentrations of fluoride added to public water supplies are carefully regulated and considered safe for human consumption. Major health organizations continue to support water fluoridation as a safe and effective public health measure for preventing tooth decay. If you have concerns about fluoride intake, you can discuss them with your healthcare provider, but there is no need to avoid fluoridated water based on current scientific understanding 1.
From the Research
Fluoride in Drinking Water and Brain Damage
- The relationship between fluoride in drinking water and brain damage is a topic of ongoing research and debate.
- A systematic review of epidemiological and toxicological evidence on health effects of fluoride in drinking water found that the weight of evidence was strong for reduction in IQ scores in children 2.
- Another study found that 21 of 23 recent epidemiological studies reported an association between high fluoride exposure and reduced intelligence, although the authors noted that the discrepancy between experimental and epidemiological evidence may be reconciled with deficiencies inherent in most of these epidemiological studies 3.
- Animal studies have also investigated the effects of fluoride exposure on brain function, with one study finding that low concentrations of fluoride exposure during fetal development can cause anxiety-like behavior and spatial memory impairment in adult mice 4.
- A review of the literature on inorganic fluoride and brain function found that many studies provide support for a link between pre- and postnatal fluoride exposure and structural and functional changes in the central nervous system responsible for neurological and cognitive disorders 5.
- A systematic review and meta-analysis of published studies found that children in high-fluoride areas had significantly lower IQ scores than those who lived in low-fluoride areas, supporting the possibility of an adverse effect of high fluoride exposure on children's neurodevelopment 6.
Key Findings
- Reduction in IQ scores in children is a potential health endpoint for fluoride exposure in drinking water 2.
- High fluoride exposure has been associated with reduced intelligence in epidemiological studies, although the evidence is not yet conclusive 3.
- Animal studies suggest that fluoride exposure can cause changes in brain function and behavior, including anxiety-like behavior and spatial memory impairment 4.
- The mechanisms underlying fluoride neurotoxicity are not yet fully understood, but may involve disturbances in synaptic transmission and synaptic plasticity, premature death of neurons, and altered activities of components of intracellular signaling cascades 5.