RFK Jr. says Trump will remove fluoride from drinking water. Here’s what you need to know

Now it is being called up by Robert F. Kennedy, Jr. — possibly on track to lead health initiatives for the incoming presidential administration — as a practice that should be stopped. He recently claimed that Donald Trump would push to remove fluoride from drinking water on his first day in office.

This weekend, Trump told NBC News he had not discussed the issue with Kennedy, saying “but that sounds OK to me. You know, it’s possible.”

On Wednesday morning, Kennedy spoke to NPR, note about Morning Edition“We don’t need fluoride in our water. It’s a very poor way to deliver it into our systems.”

Below, a primer on fluoride in drinking water, its history of controversy, and what the science says.

What is fluoride?

Fluorine is the chemical ion of the mineral fluorine. It is naturally present in trace amounts, according to CDCin soil, water, plants and some food sources, including plants and animals. It can also be released from volcanic emissions or as a by-product from the manufacture of aluminium, fertilizers and iron ore.

Once inside the body, according to National Institutes of Health Office of Dietary Supplements80% of what is ingested is absorbed in the gastrointestinal tract, with about 50% retained in the adult body – all but 1% stored in bones and teeth – and the other 50% excreted in the urine. In young children, up to 80% of absorbed fluoride is retained, as more is taken up by bones and teeth than in adults.

Why is there fluoride in drinking water?

Fluoride serves to prevent or reverse tooth decay and stimulate new bone formation, according to the NIH.

In 1945, Grand Rapids, Mich. became the first city in the world to fluoridate its drinking water. This came about after a doctor’s research into fluoride and fluorosis – discoloration of tooth enamel from an excess of fluoride – and his hunch that safe levels could serve to prevent cavities.

Grand Rapids fluoridation became a 15-year project, according to National Institute of Dental and Craniofacial Researchwith researchers monitoring the rate of tooth decay among 30,000 school children; after 11 years, it found that the cavity rate among Grand Rapids children born after fluoride was added to the water supply dropped by more than 60%. It was considered a scientific breakthrough that could revolutionize dentistry.

Since 1962, the US Public Health Service has recommended the addition of fluoride to tap water to reduce the risk and severity of tooth decay, according to the NIH. At the moment is CDC notesthe recommended concentration—which is not enforceable and is a decision made at the local, not federal, level—is 0.7 mg/L. The CDC says drinking water with fluoride keeps teeth strong and reduces cavities by about 25% in children and adults. (Another common source of fluoride is toothpaste, which, when you brush with it, sticks fluoride to the surface of the tooth, according to to CDCand increases the amount of fluoride in saliva, which helps rebuild the outer enamel layer.)

Today, fluoridated municipal drinking water—including tap water and food and beverages prepared with municipal drinking water—accounts for about 60% of fluoride intake in the United States in 2022, notes the CDCmore than 209 million people, or 72.3% of the US population served by public water supplies, had access to water with fluoride levels that prevent dental caries.

The chemicals used to fluoridate drinking water in the United States, according to NSFare fluorosilicic acid, sodium fluorosilicate and sodium fluoride, which are by-products from the production of phosphate fertilizer.

The CDC has one website showing fluoride levels in tap water by county.

Is fluoride in drinking water safe?

Yes, says the CDC, which published a statement on the safety and effectiveness of fluoridated water earlier this year.

It noted: “The safety and benefits of fluoride are well documented and have been extensively reviewed by numerous scientific and public health organizations. The US Public Health Service; the United Kingdom’s National Institute for Health Research, Center for Reviews and Dissemination, at the University of York; and the National Health and Medical Research Council, Australia have all conducted scientific reviews by expert panels and concluded that community water fluoridation is a safe and effective way to promote good oral health and prevent decay US Community Preventive Services Task Forcebased on systematic reviews of the scientific literature, issued a strong recommendation in 2001 and again in 2013 for community water fluoridation for the prevention and control of dental caries.”

Why is fluoride in tap water controversial?

In his posted comment to X on 2 Novwrote Kennedy, “​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​ ​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​ ​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​

While he may be right about the source, in its recent statement the CDC disputes the health risks Kennedy raises, noting that the only potential risk is fluorosis from excess fluoride over a long period of time.

“Expert panels of scientists from the United States and other countries with expertise in various health and scientific disciplines,” it noted, “have considered the available evidence in the peer-reviewed literature and have found no compelling scientific evidence linking community water fluoridation to any potential adverse health effect or systemic disorder 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.”

This does not mean that the addition of fluoride to water has been without controversy all these years – from the late 1940s, when activists on the far right of American politics argued that fluoridation was part of a far-reaching plan to impose a socialist or communist regime.

Later, in 2016, a Harvard Public Health article questioned the safety of fluoridated drinking water, which increased the potential for brain toxicity, based on laboratory animal experiments and other studies linking it to learning, memory and cognitive deficits.

That story prompted a cavalcade of letters — some supportive, including from the dentist, researcher and former head of preventive dentistry at the University of Toronto, who worked for years on a comprehensive scientific review of fluoride toxicity. He noticed“I was trained in traditional dentistry and for many years accepted the prevailing view of the dental/medical establishment in Canada and the US that water fluoridation is ‘safe and effective’… I was wrong.”

But many more responses were harshly critical of the article, such a one from a group of dentists, including the dean of the Harvard School of Dental Medicine, who called for it to be retracted and provided pages of evidence of where the article went wrong.

According to to NIHhigh doses of fluoride—typically from rare accidents with excessive levels of fluoridated water or accidental ingestion of fluoride dental products intended for topical use—can result in nausea, vomiting, abdominal pain, diarrhea, periostitis, and even, rarely, death. But such an acute dose, the NIH notes, “would be virtually impossible to achieve from water or toothpaste containing standard levels of added fluoride.”

Another possible result of chronic, excess fluoride intake is skeletal fluorosis, which can lead to symptoms ranging from joint pain to osteoporosis and muscle wasting. But it is “extremely rare” in the United States, the NIH notes, with no evidence that it is caused by the recommended level of fluoride in tap water.

Furthermore, the NIH adds, while one study found an association between higher maternal urine fluoride concentration during pregnancy with higher rates of neurobehavioral problems in a 3-year-old child, another similar study found no such association.

Regarding the claim that higher fluoride intake during early development is associated with lower IQ and other cognitive impairments, the NIH adds, researchers, including those behind a National Academies of Sciences, Engineering and Medicine review, consider the evidence to be weak and methodologically deficient.

Finally, regarding claims about fluoride and bone cancer American Cancer Society (ACS) points out that many systematic reviews of the link have found “inadequate” conclusions and “no clear link.” It notes that some of the controversy about the possible link stems from an old (1990) animal study that found higher-than-expected rates of osteosarcoma — a rare bone cancer — in male labs drinking fluoridated water.

Many population-based studies, meanwhile, have looked at the potential link between water fluoride levels and cancer and “have not found a strong link to cancer,” the ACS reports.

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