‘The science of fluoride is beginning to evolve’: behind the mineral’s risks and benefits

A The national conversation about fluoride’s health benefits exploded this fall after a federal toxicology report, a court ruling and an independent scientific review all called for an updated risk-benefit analysis.

Fluoride, a naturally occurring mineral in some regions, has been added to community water supplies since the mid-20th century, when research found that exposure dramatically reduced tooth decay.

The controversy, heightened by the description of the mineral as “industrial waste‘ by Robert F Kennedy Jr., Donald Trump’s choice to lead the US Department of Health, highlights some questions towns what we are now grappling with: Should the mineral’s well-established protective effects against tooth decay be prioritized, otherwise Americans, and especially children, will be exposed to unnecessary pain and embarrassment from an unhealthy smile? Or should priority be given to the possibility of neurodevelopmental effects even as studies continue?

“Fluoride is the perfect example of helping people without them having to do anything,” said Dr. Sreenivas Koka, former dean of the University of Mississippi Medical Center’s school of dentistry. The state is a ‘dental desert’, where there is only one dentist for everyone 2,120 inhabitants. “Fluoride in the water – all you have to do is drink water and you will benefit from it.”

Fluoride is added to approx 72% of community water supplies in the US, according to the Centers for Disease Control and Prevention (CDC). The CDC again endorsed the practice in a scientific statement issued in May this year, which stated that no “convincing scientific evidence has been found linking water fluoridation in the community with potential adverse health effects or systemic disorders such as increased risk of cancer, Down syndrome , heart disease, osteoporosis and bone fractures, immune disorders, low intelligence, kidney disease, Alzheimer’s disease or allergic reactions”.

Yet the water fluoridation controversy recently made headlines following two high-profile reports and a federal court ruling. The U.S. National Toxicology Program caused a firestorm in August when it published a paper systematic review who found with “moderate confidence” that children exposed to fluoride levels twice that recommended for drinking water (1.5 mg per liter versus the recommended 0.7 mg per liter) “are consistently associated with lower IQ in children ”.

Then in October, a new Cochrane Review lowered the estimated impact of fluoride, citing the widespread use of fluoride in toothpaste from 1975 onwards.

“Studies conducted in 1975 or earlier showed a clear and important effect on the prevention of tooth decay in children,” said Cochrane Review researchers wrote. “However, due to the increased availability of fluoride in toothpaste since 1975, it is unlikely that we will see this effect in all population groups today.”

The public debate comes as the National Institutes of Health (NIH), the largest publicly funded research agency in the world, is both a major funder of research that advances society’s understanding of the non-dental health effects of fluoride, and a agency that is squarely in line with Trump. crosshair.

The agency is one of the main targets for cuts and restructuring. Paradoxically, that could mean critics like Kennedy are scaling back research on fluoride, while the NIH funds research into possible harmful effects. The new administration has made no proposals on how to improve oral health in the US.

The health benefits of fluoride were researched in the early 20th century, when in Colorado Springs dentist wondered why city dwellers had brown, stained and decay-resistant teeth – now known as dental fluorosis.

It was later discovered that fluoride naturally occurred in high concentrations in Colorado Springs, causing the cosmetic defects. Its spoilage-resistant properties were confirmed in a landmark 1945 study in Grand Rapids, Michigan, which found that children in Grand Rapids 60% less likely to develop caries (better known as cavities) with fluoride added to water.

In 1999, the CDC greets water fluoridation as one of the biggest public health victories, alongside seat belts and vaccination. That view was supported by a Cochrane Review 2015considered the gold standard, led to an almost 26% reduction in the case of tooth decay, a figure still cited today by the American Dental Association (ADA) and American Academy of Pediatrics (AAP).

The need for preventive oral health solutions is great in the US – more than that 68 million people lack of dental insurance and all that one in four adults said in one survey that they have avoided the dentist because of costs.

Moreover, schoolchildren are estimated to lose an average of € 34 million school hours annually due to unexpected dental visits; 2 million Americans visit the emergency room every year for toothache; half a million people travel abroad for cheaper care and one in five American seniors does not have a single natural tooth. The lack of dental access is so common in some areas that doctors in prison often have patients who have never seen one.

“One of the things I regularly ask young people in juvenile detention is: ‘Do you have a doctor? Do you have a dentist?’” said Dr. Fred Rottnek, former medical director of St. Louis County jails in Missouri and now a professor of community medicine at Saint Louis University School of Medicine. “Many of them have never reported going to the dentist.”

Modern research into the non-dental health effects of fluoride began to gain momentum in 2015, when the National Toxicology Program (NTP) asked a systematic review on the impact of fluoride on neurological development. In 2019, toxicology researcher Bruce Lanphear, from Simon Fraser University in Canada, co-authored a study showing that fluoride exposure associated with a reduced IQ, which would later be included in the systematic review of the NTP.

“That gives you an indication that the science of fluoride is starting to evolve – it wasn’t set in stone 70 years ago,” he said.

Lanphear, and a small group of like-minded toxicology researchers, argue that now is the time to “pause and let an independent scientific committee look at all this new evidence” as “we have a lot of new science specifically about fluoride and the developing brain ,” he said.

Critics gained renewed support when a federal court ruled in September that the Environmental Protection Agency (EPA) must assess fluoride under the Toxic Substances Control Act.

But doctors, dentists and mainstream professional associations, from the American Dental Association to the American Academy of Pediatrics, stand behind fluoridated water recommendations.

While some cities step away of fluoride, communities such as Buffalo, New Yorkare restarting programs.

“This is a shame if we do not use what we know from science,” says Koka about the preventive effect of fluoride. “Are there challenges to doing it well? Yes, but do they have to be so strong that they overcome all attempts at all? That is a tragedy.”

The CDC has also refined guidelines on fluoridation in recent years. In 2015, water fluoridation recommendations dropped to 0.7 mg per liter of water, from 0.7 to 1.0 mg per liter, depending on climate. Later the CDC released a report in 2019 which advised parents of children under the age of two to talk to their dentist about fluoridated toothpaste, and reminded parents of children under the age of three to only use a ‘grain of rice’ smear.

While critics say federal agency recommendations are lagging behind, the U.S. government’s National Institutes of Health (NIH) has become one of the leading funders of research into fluoride’s potential impact on IQ.

“Receiving funding from the NIH shows that they are interested in this important issue,” said Christine Till, assistant professor at York University in Canada and co-investigator at Lanphear, whose grant study dental dentin and Neurodevelopment in Canada was funded by the NIH but rejected by the Canadian government.

Others, such as Ashley Malin, professor of epidemiology at the University of Florida, and Dana Goin, assistant professor of epidemiology at Columbia University, have also received NIH funding to investigate the non-dental health effects of fluoride. Malin studies the impact of fluoride on children’s sleep and Goin investigates reproductive health effects.

“A lot is being done in this area, especially in the US,” says Goin. “Hopefully, the results of these studies will help determine whether the EPA drinking water regulations and the CDC recommendations for water fluoridation provide an adequate balance between improvements in dental health from fluoridation and any potential negative effects.”

Goin’s current funding builds on her previous work, which found that water fluoridation was not associated with small-for-gestational age or preterm birth. She is now investigating whether fluoride is associated with gestational diabetes.

Malin added that it is a sign of “progress” that the studies can be discussed: “More than a decade ago, it was quite controversial to even ask the question of whether optimal fluoridated water, or its concentration in drinking water, affects neurological could influence development.”