Australia to review water fluoridation guidelines amid debate over prenatal fluoride and IQ

The NHMRC, which currently advises that it is safe for pregnant and breastfeeding women to drink fluoridated water, will conduct a comprehensive review of emerging evidence, acting chief executive Prue Torrance said. She was responding to a question from South Australian Liberal senator Alex Antic, who asked if the advice would be reviewed in light of research indicating fluoride crossed the placenta and was linked to adverse neurodevelopmental outcomes, including reduced intelligence in children.

Since the 1960s, fluoride has been added to Australia’s public water supplies at 0.6 to 1.1 milligrams per litre to reduce tooth decay. The NHMRC’s current advice is based on a 2016 review of the scientific literature.

Australian Dental Association vice president Dr Angie Nilsson said an overwhelming weight of evidence showed fluoridated water was a safe public health measure that reduced tooth decay. She referred to a 2025 longitudinal study that found no difference in the IQ of Australian children who were exposed to fluoride during early childhood and those who were not. Nilsson said Australian guidelines strictly controlled water fluoridation well within safe limits recommended by the World Health Organisation.

“It is actually a really alarming thing when someone’s saying to a pregnant woman, ‘you shouldn’t be having fluoridated water’,” she said.

Nilsson welcomed the review, saying it would add to the weight of evidence supporting fluoridated water and ensure trust in the public health measure. “We’re in a society now where there’s a lot of alarmist views, and people look into information that isn’t necessarily evidence-based,” she said.

Dr Ian Musgrave, a molecular pharmacologist and toxicologist at the University of Adelaide, said the issue was emotional but that at concentrations used in potable water in Australia, Europe and the US, there did not seem to be any effect on IQ in children, citing studies that accounted for numerous confounding factors. He said limitations of studies showing a link to lower IQ “mean that you really can’t take this incredibly seriously.”

Several large studies have concluded that consuming fluoride at recommended levels has no adverse effects, including a 2025 US study involving 26,820 school students, some followed up 40 years later. A 2022 study involving 2700 Australian children found no evidence of a link between fluoride and IQ, with a 2025 Australian study reaching a similar conclusion.

However, other recent studies have prompted calls for agencies to review their advice, particularly for pregnant women. A 2025 Swedish study of 500 mothers and their children in Bangladesh found that low exposure to fluoride during pregnancy was linked to subtle declines in children’s intelligence at five and 10 years old. A 2024 systematic review by the US National Toxicology Program concluded with moderate confidence that there is some evidence of an association between lower IQ in children and exposure to high levels of fluoride, above the WHO-recommended level of 1.5mg per litre, well above concentrations in Australian drinking water.

A NHMRC spokeswoman said the review would be informed by systematic reviews of the literature, including consideration of recent international studies. An expert committee would advise on the scope and research questions.

International consensus among researchers and major public health bodies is that there is a lack of evidence to support a causal link between fluoridated water in pregnancy and lower intelligence in children, noting conflicting findings and significant limitations of some studies’ designs.