Before President-elect Donald Trump was elected, Robert F. Kennedy Jr. raised alarm bells among some public health experts by stating he would push for the removal of fluoride from America’s drinking water. He claimed that Trump agreed with him and that, if elected, it would be one of the administration’s top priorities.
“On Jan. 20, the Trump White House will advise all U.S. water systems to remove fluoride from public water,” Kennedy posted on X, formerly Twitter, earlier this month. He described fluoride as “an industrial waste” linked to a range of health concerns, including arthritis, thyroid disease, and lower IQ in children.
In a move that sparked sharp criticism from public health officials and Democrats, Kennedy was nominated to lead the Department of Health and Human Services (HHS) on Thursday, fulfilling Trump’s promise to give him a high-profile position in the new administration, with the purview to “make America healthy again.”
Critics argue that appointing someone with a history of controversial statements on vaccines and food safety to lead a major agency overseeing drug and vaccine safety, food regulations, medical research, Medicare, and Medicaid is both “dangerous” and deeply troubling.
But while many of Kennedy’s views are seen as wildly out of mainstream thinking, his stance on fluoride is more nuanced than it might seem, according to some public health experts.
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What Is Flouride?
Fluoride is a naturally occurring mineral that has long been known to prevent tooth decay. Bacteria in the mouth produce acid that dissolves the tooth’s surface, eventually leading to cavities. Fluoride replenishes lost minerals from wear and tear and strengthens dental enamel.
Since the 1950s, federal officials have endorsed water fluoridation as a measure to prevent tooth decay, continuing to promote the practice even after fluoride toothpaste became widely available several years later. While fluoride can be found from various sources, researchers note that drinking water remains the primary source for most Americans.
The Centers for Disease Control and Prevention (CDC) credits water fluoridation with reducing cavities by approximately 25 percent, describing it as one of the 20th century’s top 10 public health achievements. The CDC recommends a fluoride concentration of 0.7 milligrams per liter in drinking water, which has been shown to reduce tooth decay.
“There is excellent, solid data going back 75 years showing that fluoride is safe and extremely effective at decreasing dental decay,” said Dr. Aaron Yancoskie, associate dean at Touro College of Dental Medicine, in a CBS News interview. The CDC also cites studies from Alaska and Canada that saw significant increases in cavities among children after fluoridation programs ended.
That does not mean flouride is entirely risk-free. Like most things in health, it comes down to dosage. Excessive levels can lead to issues such as tooth discoloration, bone deformities and thyroid problems. In 2015, officials adjusted their recommended fluoride levels in drinking water to reduce the prevalence of fluorosis—a condition that causes white or brown splotches on teeth and had become increasingly common in U.S. children.
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Multiple studies also show that neonatal fluoride exposure might interfere with brain development. In August, the National Toxicology Program, part of the National Institute of Health, determined “with moderate confidence” that there is a link between higher levels of fluoride exposure and lower IQ in children. The agency based its conclusion on studies involving fluoride levels at about twice the recommended limit for drinking water.
“I think this [report] is crucial in our understanding” of this risk, said Ashley Malin, a University of Florida researcher who had studied the effect of higher fluoride levels in pregnant women on their children. She called it the most rigorously conducted report of its kind.
A 2023 Canadian study found that exposed girls were more impacted, with worse cognitive flexibility and executive function. Three studies from Mexico also found a link between fluoride intake during pregnancy and a significant drop in IQ, attention-deficit/hyperactivity symptoms and cognitive development problems in the offspring.
A Global Divide Over Fluoride
Unlike the United States, where nearly 73 percent of the population receives fluoridated water, many European countries don’t do it at all, opting instead for alternative strategies to combat dental decay. Germany, the Netherlands and most of Scandinavia rely on fluoride toothpaste and other dental products rather than adding fluoride to their water supply. Advocates for the European model argue that cavity rates remain low without water fluoridation.
“If Kennedy succeeds in persuading Trump to recommend against fluoridation, he would actually be aligning the United States with peer countries. That could result in a slight increase in tooth decay, but it could also benefit Americans by reducing prenatal exposure,” wrote Dr. Leana Wen, an emergency physician and clinical associate professor at George Washington University, in an essay for The Washington Post this week.
However, if fluoridation were to end, the dental health outcomes in cities like Calgary, Canada, offer a cautionary tale. Calgary discontinued water fluoridation in 2011, and since then, rates of dental surgeries for severe cavities in children have steadily risen, according to data from the University of Calgary.
In the U.S., only one state, Hawaii, has banned fluoridation. Most states leave the decision to local governments. Cities like Portland, Oregon, and Wichita, Kansas, have consistently rejected fluoridation proposals through voter referendums. Recently, more localities have followed suit. Since 2023, towns in North Carolina, Florida, Pennsylvania, and Texas have opted to discontinue the practice.