Fluoride has been in US water supplies for 80 years. Why is it so controversial?
Fluoride didn’t make much of a splash in the public eye when fluoridation trials began in 1945. The first run only reached about 232,000 Americans at the time. Nearly a decade later, the number of Americans receiving fluoridated tap water exceeded 20 million, or roughly 12% of the population at the time.
It would still take decades for widespread adoption to happen. By 1980, fluoridated water reached more than half of Americans. By 2012, only 67.1% of Americans had access to fluoridated tap water, according to the Centers for Disease and Prevention. Today, the number stands at 72%.
Yet despite its careful 80-year adoption and a mountain of scientific evidence supporting its frankly revolutionary benefits to public health, American sentiment surrounding fluoride seems to be waning as many water utilities have started to move away from the practice amid growing public pressure.
Over the decades, enough research has consistently shown that fluoridation helped dramatically reduce cavities in children, though its efficacy in adults is less clear.
The controversy surrounding fluoride is its adverse effects. Too much fluoride can cause one known issue: dental fluorosis. Fluorosis is a mild tooth development that can change the way children’s teeth look during development, such as causing white streaks.
Online, fluoride has been the subject of plenty of conspiracy theories linking it to everything from causing cancer to lowering your IQ.
So, what exactly is fluoride and do online conspiracies have any validity? Here’s what to know.
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?
Nope. 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 report 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.
This article originally appeared on Pensacola News Journal: Fluoride has been in US water supplies for 80 years. Why is it so controversial?
