Studies link fluoride in water to lower IQ, but is it really harming kids’ brains?
Study says fluoride in drinking water could lower kids’ IQs, but some experts say that’s based on bad data. Here’s what you need to know.
Straight Arrow News
The Florida House approved a bill that is setting the state up to become the second in the country to ban fluoride from being added to water supplies.
The GOP-controlled House passed the bill (SB 700) in an 88-27 vote on Tuesday, which also prevents the sale of plant-based products “mislabeled” as milk, meat, poultry or eggs.
Utah became the first state in the United States to pass a bill banning fluoride on March 29. Health and Human Services Sec. Robert F. Kennedy has endorsed claims that fluoride is behind a host of health conditions including ADHD, lower IQ, and hypothyroidism. Dentists and epidemiologists have hit back at those accusations as scientifically unproven, and have warned that removing fluoride from water systems could take a serious toll on public health.
Kennedy has praised Utah’s ban and he took another swipe at the mineral in a Cabinet meeting on April 30.
Brett Kessler, president of the American Dental Association, called the claims that fluoride is harmful and unnecessary a “myth.”
“When government officials, like Secretary Kennedy, stand behind the commentary of misinformation and distrust peer-reviewed research it is injurious to public health,” he said in a statement on Monday.
Over the past 80 years, the U.S. adopted the practice of adding fluoride to water supplies, which the Centers for Disease and Prevention has listed as one of the 10 great public health achievements between 1900-1999.
Yet despite its careful adoption and a mountain of scientific evidence supporting its benefits to public health, American support for fluoride seems to be waning as many water utilities have started to move away from the practice amid growing public pressure.
Here is what to know about Florida’s proposed fluoride ban, dubbed the “Florida Farm Bill” and the effects of fluoride.
What does Florida’s fluoride ban bill (SB 700) do?
The Florida Farm Bill is a 111-page piece of legislation that touches on nearly two dozen aspects related to agricultural and consumer services, such as adopting rules for electric vehicle charging stations, allowing drones to be used to manage and eradicate plant and animal disease and more.
The legislation never mentions fluoride. Instead, it seems to add a new section to Florida Statutes that defines water quality additives and prohibits local governments from adding any additive that doesn’t meet the definition.
Under the bill, a water quality additive is any chemical, additive or substance used in public water systems for the purpose of:
- Meeting or surpassing primary or secondary drinking water standards
- Preventing, reducing or removing contaminants, or
- Improving water quality
Adding fluoride to public water supplies does not fall under the newly proposed definition and is largely seen as a public health measure.
“Not only is it (water fluoridation) safe, it’s a game-changer for dental health,” Rep. Anna Eskamani, D-Orlando, said.
Proponents of the bill argue that it shouldn’t be up to the government to decide whether to put drugs and chemicals in people’s bodies.
“This is not about fluoride,” said bill co-sponsor Rep. Danny Alvarez, R-Hillsborough. “This is about your liberty.”
What is fluoride?
Fluoride is a mineral that can be naturally found in soil, all water and even many foods, according to the Cleveland Clinic.
Even prior to its first trial in 1945, fluoride had undergone decades of study. In 1901, dentists in the United States and Italy separately found that certain populations with distinctively stained teeth had lower rates of dental decay. The discovery was later described as “dental mottling.”
Researchers spent years trying to understand the correlation between dental mottling and tooth decay, often going back and forth between whether or not it increases someone’s chance of experiencing tooth decay.
G.V. Black, dean of Northwestern University Dental School, and Dr. Frederick S. McKay began studying the correlation in 1915. A year later, they published a paper revealing that “Contrary to what might be expected [mottling] does not seem to increase the susceptibility of the teeth to decay.”
The studies didn’t end there, however. In 1931, Dr. H. Trendley Dean, U.S. Public Health Service officer and founder of the Dental Hygiene Unit at the recently established National Institutes of Health, correlated mottled enamel with too much fluoride intake. After publishing a long-running series of epidemiologic studies exploring the relationship between fluoride intake, dental fluorosis, and tooth decay, he declared fluorosis an “an acute and urgent public health problem.”
Dean’s intent wasn’t to vilify the use of fluoride. After his declaration, he pivoted his studies toward whether fluoride at levels too low to cause fluorosis might provide resistance to cavities. He discovered “a strong inverse relation” between the conditions.
In 1942, Dean published the findings of an NIH study of 7,200 children spanning 21 cities. He found that 1 ppm fluoride in drinking water reduces rates of tooth decay with negligible risk of fluorosis. His revised fluorosis index remains in clinical use to this day, according to the CDC.
What are the benefits of fluoride?
After more than 80 years of study, fluoride’s benefits are pretty clear-cut. When a community is able to precisely adjust the level of naturally occurring fluoride in its water supply, it leads to the single most effective, safe and cost-effective way to prevent dental decay and repair early tooth decay, according to the Florida Dental Association.
The CDC estimates that fluoridation has reduced tooth decay in children by 40-70% and reduced tooth loss in adults by 40-60%. Community water fluoridation is listed in the CDC’s 10 great public health achievements between 1900-1999.
A lot of studies focus on the benefits fluoride provides children, but it helps adults in several ways, too.
The Cleveland Clinic says that fluoride can help treat dry mouth, which makes people more prone to oral health issues like gum disease and cavities. It can help fight gum disease, which exposes teeth and gums to bacteria and increases your risk of tooth decay.
Fluoride also helps anyone with crowns, bridges, braces or removable partial dentures, which can also increase the risk of cavities.
What are the arguments against fluoride in water?
In November, Florida Surgeon General Dr. Joseph Ladapo issued official guidance against public utilities putting fluoride in drinking water.
“It is clear more research is necessary to address safety and efficacy concerns regarding community water fluoridation,” Ladapo said in November. “The previously considered benefit of community water fluoridation does not outweigh the current known risks, especially for special populations like pregnant women and children.”
However, there have been more than 3,000 studies from the U.S. and across the world that address the safety and efficacy of community water fluoridation.
Other claims link fluoride to cancer, lower IQs and an increased risk of childhood neurobehavioral problems.
Outside of fluorosis, there have been no studies that link the CDC-prescribed amount of 0.7mg/L to things like an increase in kidney disease, bone cancer, ADHD or any other neurodevelopmental disabilities.
There have been studies that link greater concentrations of fluoride to lower IQ. However, those studies were from countries such as Canada, China, India, Iran, Mexico and Pakistan and involved fluoride levels at or above 1.5 milligrams per liter, twice the recommended U.S. limit. The authors said more research is needed to understand whether lower exposure has any adverse effects.
In the reports, researchers said they found no evidence that fluoride exposure adversely affected adult cognition.
Do Brita filtration systems filter fluoride?
No. Brita filters are designed and certified to filter out several contaminates like chlorine, chloramine, lead, PFAS and microplastics but not fluoride. You can check the certification seal on your Brita and filter to better understand what contaminates are filtered.
What does fluoride do to your brain?
The NIH-run National Toxicology Program’s (NTP) monograph on fluoride found with moderate confidence that higher levels of fluoride exposure, such as drinking water with more than 1.5 mg of fluoride per leader, are associated with lower IQ in children. The study was criticized by the National Academies of Sciences, Engineering and Medicine and the American Dental Association for inadequate statistical rigor and other methodological flaws.
The study stressed that there was “insufficient data to determine if the low fluoride level of 0.7 mg/L currently recommended for U.S. community water supplies has a negative effect on children’s IQ.” The report also stated that there was no evidence of fluoride exposure having a negative impact on adult cognition.
Contributing: Cybele Mayes-Osterman and Swapna Venugopal Ramaswamy of USA Today.