Councils are voting to remove fluoride from drinking water \u2014 so why did we add it in the first place, and how can you protect your teeth if you’re losing access to it?<\/p>\n
Professor Do is very confident there is no link between fluoride exposure and cognitive development.<\/p>\n
“I think we can close the book there,” he says.<\/p>\n
Despite mounting scientific evidence on the safety \u2014 and health benefits \u2014 of fluoride, there’s still concern in some pockets of the community that fluoride is a “neurotoxin”, and dangerous to cognitive development.<\/p>\n
Even though there is little evidence to support these concerns, they’ve prompted some local governments in Australia<\/a> and some US states<\/a> to remove fluoride from their water supplies.<\/p>\n So let’s unpack what the research tells us.<\/p>\n Is fluoride really a neurotoxin?<\/p>\n Technically fluoride is a neurotoxin, but not in amounts you’re likely to encounter.<\/p>\n Oliver Jones, a chemist at RMIT University, says you’d need to eat huge quantities of fluoride-containing substances to see any toxic effects.<\/p>\n But we’re not usually exposed to enough fluoride to cause problems.<\/p>\n “Anything is a toxin if you have enough of it,” Professor Jones says.<\/p>\n “Even water is a neurotoxin if you drink enough.”<\/p>\n People understand this with other substances, such as alcohol, he says.<\/p>\n “Everyone knows if you drink too much, you’re going to get liver damage and you can have cancer.”<\/p>\n Fluoride is added to Australian tap water at levels of 0.6-1.1 milligrams per litre. (Unsplash: Jacek Dylag)<\/p>\n Ian Musgrave, a toxicologist at the University of Adelaide, says fluoride is used in high concentrations as a poison, such as in some pest baits.<\/p>\n But studies have been done to establish how much fluoride is required to poison animals, and how much they can safely be exposed to.<\/p>\n There’s a wide margin between the level of fluoride that causes harm to animals, and the amount added to water.<\/p>\n “The levels that are in potable water are about 50\u2013200 times lower than the concentration that has no effect on animals,” Dr Musgrave says.<\/p>\n While we also get fluoride from other sources, like toothpaste, this still doesn’t bring us up to a dangerous exposure level.<\/p>\n “When they set the limits for fluoridation in water, it takes into account all the sources.”<\/p>\n Gympie the latest council to stop fluoridation<\/a><\/p>\n The latest Queensland council’s decision to stop fluoridating water has left Queensland public health experts gagging, writes Janelle Miles.<\/p>\n This is why toothpaste tubes say “do not swallow”: accidentally swallowing some while brushing your teeth is fine, but all the fluoride in the tube of toothpaste could potentially be dangerous in one hit.<\/p>\n “You probably have to eat an entire tube of toothpaste to cause significant harm,” Dr Musgrave says.<\/p>\n If you do manage to eat enough fluoride to suffer from its toxicity, Professor Jones says that other parts of the body are affected before the brain is.<\/p>\n Teeth and bones show the first signs of fluoride overexposure, with a condition called “fluorosis” staining and eventually weakening tooth and bone structure.<\/p>\n “The amount that you would need to have negative effects on the brain is extremely high, and you would see other effects first like dental fluorosis or even skeletal fluorosis.”<\/p>\n Is there a link between fluoride and IQ?<\/p>\n Large studies have found no link between fluoride and IQ.<\/p>\n A couple of small studies flagged a link between fluoride exposure and lower IQ levels, alongside a heavily<\/a> criticised<\/a> review by the US National Toxicology Program earlier this year.<\/p>\n “Most of those studies were not well conducted, without controlling for other factors,” Professor Do says.<\/p>\n For instance, some of the places with naturally high fluoride levels also had heavy metal contaminants in their water supply.<\/p>\n However, larger studies have not been able to replicate the link.<\/p>\n Loading…<\/p>\n A study, published today in the journal Science Advances<\/a> analysed data from academic tests of 26,820 teens who went to more than 1,000 high schools across the US in 1980.<\/p>\n They found no evidence students living in areas with fluoridated water performed worse than those living in unfluoridated areas when they were in high school; there may have even been a small benefit to children in fluoridated areas.\u00a0<\/p>\n There was also no impact of fluoridation on a subset of students who were followed up 40 years later.<\/p>\n Large studies on Australian children by Professor Do also show no evidence for a link between fluoride and IQ.<\/p>\n In 2022<\/a>, Professor Do and his colleagues examined cognitive development tests for nearly 2,700 children, over a course of seven or eight years.<\/p>\n They did not find any link between fluoride exposure and cognitive development.<\/p>\n<\/p>\n