High levels of fluoride exposure has been linked to lower IQ in children. Fluoride is a mineral that naturally occurs in water, soil, and plants. It is added to products to prevent tooth decay and in several over-the-counter drugs.
While fluoride consumption in given range is safe, large amounts of exposure can be dangerous. The US government’s National Toxicology Program (NTP) recently conducted a meta-analysis which highlighted the potential neurodevelopmental risks associated with excessive fluoride exposure.
The study found a statistically significant association between higher fluoride exposure and lower IQ scores in children, raising questions about the balance between fluoride’s dental benefits and its broader health implications.
Low IQ (intelligence quotient) in children refers to a measure of cognitive abilities that are below the average for their age group. IQ tests are standardised assessments designed to evaluate intellectual skills, problem-solving abilities, and reasoning.

In children, low IQ could mean developmental delays in learning basic skills, struggling with communication, not understanding complex concepts or might need support in daily decision-making.
Since its introduction in 1945, fluoride has been a cornerstone of public health efforts to reduce dental cavities, the researchers revealed.
However, the meta-analysis, published in JAMA Pediatrics, evaluated 74 epidemiological studies from ten countries, including India, China, and Mexico, and revealed concerning trends.
Fluoride and IQ Decline: The analysis reported that for every 1 mg/L increase in urinary fluoride, children’s IQ scores decreased by 1.63 points.
High Exposure Threshold: Significant IQ reductions were observed at fluoride exposure levels exceeding 1.5 mg/L in drinking water or urine.
Limited Data on Lower Levels: There was insufficient evidence to conclude whether fluoride levels at or below 0.7 mg/L – the US Public Health Service’s recommended level – have adverse effects on IQ.
Excess fluoride exposure is not a new issue in India. Groundwater in regions like Haryana, Punjab, and Rajasthan often contains fluoride levels exceeding safe limits.
Dr. Kadam Nagpal, Head of Neuroimmunology at Salubritas Medcentre, explained that this has led to health complications such as dental and skeletal fluorosis and potential neurological impairments in children.
“Excessive fluoride gets deposited in teeth, bones, and soft tissues, altering metabolism. This can impair learning and memory in children,” said Dr. Nagpal.
India’s National Programme for Prevention and Control of Fluorosis (NPPCF) monitors and mitigates high fluoride levels in groundwater. Measures like installing reverse osmosis (RO) plants and raising awareness about fluoride-containing products are some critical components of the initiative.