Should the US ban fluoride in its drinking water?

US President-elect Donald Trump promised to let Robert F. Kennedy Jr. take the lead on health care. Presidential candidate Mr. Kennedy, who dropped out of the race in August and endorsed Mr. Trump, may be one step closer to doing so. On November 14, Mr. Trump tapped him to be health secretary in his incoming administration. Elected in (although his appointment would require confirmation by the Senate).

Mr Kennedy has vowed to “make America healthy again”. But, worryingly, he spreads a number of lies, including the idea that childhood vaccinations are linked to autism. Now he has his sights set on fluoride: Mr. Kennedy wants the federal government to ban it. From America’s water supply on the day of Mr Trump’s inauguration. Not all scientists dismiss Mr. Kennedy’s views on this issue as nonsense. Should Americans take their concerns about the mineral seriously?

Fluoride helps prevent tooth decay. It occurs naturally in some foods – for example tea, potatoes and shrimp – and in some waters. In 1945, Grand Rapids, Michigan, became the first US city to add it to its drinking water. Today more than two-thirds of Americans have piped water piped into their homes.

After the introduction of fluoridation, dental problems in children reduced significantly. The average number of decayed, missing or filled teeth in children by age 12 declined by 68% between 1966 and 1994. The Centers for Disease Control and Prevention (CDC) has listed fluoridated water as one of the top ten public-health achievements of the 20th century. This is especially helpful for children with poor diets who do not have regular dental appointments. In 2020 the Department of Health and Human Services (HHS) vowed to increase the percentage of Americans with fluoridated tap water by more than three-quarters within ten years.

But Mr. Kennedy wants to put a stop to it—and some scientists believe there are good reasons to do so. At the very least, fluoridated water may be unnecessary. Some studies conducted after 1975, by the time fluoride became a common ingredient in toothpaste, found that fluoridated water had little or no benefit. (Others have found the opposite: fluoridated water is much better for children’s dental health.) Worse, consuming too much of the mineral can have harmful effects. Some consequences, such as dental fluorosis, which causes white spots or lines on children’s teeth, are largely cosmetic. Others are more serious: Skeletal fluorosis distorts and weakens the bones. But it is extremely rare in the US – in 2004 HHS said only five such cases had ever been reported.

Mr. Kennedy is more concerned that excessive fluoride intake could lower IQ. This may sound strange, but scientists are investigating it. A report by the National Toxicology Program within HHS found that high levels of fluoride exposure, twice the legal limit, were associated with lower IQ in children. Other researchers found that fluoride levels even within the legal limit were associated with that risk. And a study of American mothers found that pregnant women who drank fluoridated water were more likely to give birth to children with low IQs.

These studies do not prove that fluoride intake lowers IQ; They show a correlation. More research is needed to draw firm conclusions. A federal judge in San Francisco recently ruled that the Environmental Protection Agency must review the potential danger posed by fluoridated drinking water. In contrast, Mr. Kennedy seems willing to ban fluoride first and ask questions later. But a quick ban would almost certainly be impossible. Currently local governments decide whether to fluoridate water, an approach to governance that Republicans generally support. A federal ban would probably take several years to go through the rule-making process, which would require more scientific evidence to support it. If the government tried to rush things, it would raise the possibility of legal challenges from opponents like the American Dental Association. Such challenges are already highly probable. This process could begin on day one of the Trump administration – but banning fluoride would be like pulling teeth.

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