Since 1945, fluoride has been added to drinking water in the United States, helping to reduce cavities and significantly improve people’s dental health.
However, Robert F. Kennedy Jr., the secretary of Health and Human Services, has said he intends to remove fluoride from the country’s drinking water, based on false information about its safety. During his confirmation hearing in January, Kennedy cited an analysis of studies linking high levels of fluoride to lower IQ levels in children—despite the study’s own authors cautioning that none of the research had been conducted in the United States, where the amount of added fluoride is very low.
Experts and research confirm that the levels of fluoride in U.S. drinking water are safe.
“There is no evidence at all of any adverse effect, including effects on IQ or neurodevelopment, or anything else, at the levels that we use in the United States for community water fluoridation,” says Dr. Scott Tomar, professor and associate dean of prevention and public health sciences at the University of Illinois Chicago College of Dentistry, to Public Good News.
We spoke to several experts about fluoride, why it’s in our water, its safety, and what the study Kennedy cited means. Read on to find out more.
What is fluoride?
Fluoride is a mineral that’s naturally found in water, air, soil, and some foods (like coffee, black tea, potatoes, and oatmeal).
Fluoride helps our teeth become stronger, which helps reduce tooth decay and cavities. Cavities, or holes that bacteria cause on a person’s teeth, can lead to infection, pain, and eventually tooth loss.
Why is fluoride in our drinking water?
Some levels of fluoride are naturally present in most water sources. Another small amount is added to public water systems in the U.S. through the process of fluoridation.
The U.S. began adding fluoride to its drinking water in 1945 to help prevent tooth decay and improve dental health. During fluoridation, the levels of fluoride in water are adjusted to 0.7 milligrams per liter, or one ten-thousandth of a teaspoon, which is the recommended amount to help protect our teeth. (A small percentage of communities naturally have this level in their water, so fluoride is not added. Others have voted to stop fluoridation.)
In the 1940s, poor dental health “was such a widespread epidemic that almost nobody made it to older ages with a relatively intact set of teeth,” adds Tomar.
Tooth loss “was one of the main reasons for medical deferment in the draft for World War II. These were 17- or 18-year-old young men who needed six teeth in contact with each other, and many of them failed because they didn’t even meet that threshold.”
When fluoridation started, cavity levels decreased between 50 and 70 percent, says Dr. Steven Levy, professor of preventive and community dentistry at the University of Iowa College of Dentistry and Dental Clinics. Now, thanks to toothpaste and mouthwashes that contain fluoride and dental treatments, fluoridated water reduces tooth decay by about 25 percent.
“The impact that it’s had on oral health is absolutely astounding,” says Jess Steier, public health scientist, CEO of Vital Statistics Consulting, and founder of Unbiased Science, to PGN. “And I think that people forget that before modern medicine and fluoride and dental treatments, people actually died from dental issues because cavities can turn into infections, and then once infections get into your bloodstream, it could be quite, quite dangerous.”
Fluoridation has been called one of the greatest public health achievements of the 20th century because “everyone can benefit, even if you don’t go to the dentist, or physician, or can’t afford the time and money to get your teeth cleaned with fluoride toothpaste,” adds Levy.
Are there any health risks associated with fluoride in our water?
The fluoride levels present in most of the U.S. water supply don’t have health risks. However, with very high levels of fluoride, there’s a risk of fluorosis, which can cause your teeth to discolor and develop stripes and can affect your bones. But skeletal fluorosis is very rare.
“[It] affects bones from very high, long-term [fluoride] exposure,” Steier says. “This is very, very uncommon in the U.S.”
Is fluoride associated with lower IQ in children?
There’s no evidence suggesting that the levels of fluoride in the U.S. are associated with lower IQ in children.
In January, the National Toxicology Program published a meta-analysis (an analysis that combines the results of different studies) linking high fluoride exposure to a slight decrease in IQ scores in children. However, the analysis’s authors noted that “there were insufficient data” to determine if current recommended fluoride levels in U.S. community water negatively affect children’s IQ.
Additionally, experts, including Tomar, Levy, and Steier, have noted several flaws in the report. First, it analyzes data from foreign countries, where fluoride levels are more than double the levels of fluoride in the U.S. Second, the authors themselves indicated that most of the analyzed studies were considered “low quality” and had a “high risk of bias.”
Steier adds that the IQ differences the analysis found were minor: “If you’re sitting with a person who’s two IQ points higher than you [on] an IQ scale, there’s no clinical difference in the ways that we interact or present, so that was a big flaw.”
What could happen if fluoride is removed from water in the U.S.?
Communities that stopped fluoridation, including Juneau, Alaska, and Calgary, Canada, “saw a fairly significant increase in the rate of tooth decay and the associated costs of treating that,” says Tomar. “Unfortunately, what I expect to see is an increased rate of disease, especially among lower-income communities.”
To find out more about the levels of fluoride in your community, check out the My Water’s Fluoride tool from the Centers for Disease Control and Prevention. You can also find more information about fluoridation and children’s health from the American Academy of Pediatrics.