The Journalist’s Resource: “Several U.S. communities are debating whether to remove fluoride from their water supplies in the wake of comments by President-elect Trump’s Health and Human Services nominee Robert F. Kennedy Jr., who called the mineral an “industrial waste,” looking to remove it from water systems across the nation once Trump takes office. Local journalists who may find themselves covering this topic will likely hear arguments from both sides. A good question to ask to inform your reporting is, “What does the research say?” To be sure, there are still unanswered questions about water fluoridation in modern times and many researchers have called for better studies. At the same time, there’s little evidence that fluoride is harmful at low levels. We have unpacked five recent studies, including systematic reviews, followed by a list of additional research. Before selecting these studies, we read through dozens of published research papers, which paint a complex and evolving picture of the water fluoridation debate. Here are some of the main takeaways from recent studies:

• The prevalence of dental cavities has decreased in recent decades, thanks to the widespread use of fluoride toothpaste and mouthwash, so the benefit of water fluoridation may be less pronounced today than it was in years after the programs were implemented in 1945.
• Evidence for the benefits of water fluoridation is largely based on older studies, many of which were conducted before the widespread use of fluoride toothpaste. But this doesn’t mean that fluoride is harmful or should be removed from water supplies, researchers note. The per-person cost of fluoridating a water system is a fraction of the cost of one dental filling.
• Water fluoridation leads to reductions in dental cavities, especially in children, both in baby and permanent teeth, research finds, especially in earlier studies. But evidence for adults is limited.
• The main negative effect of fluoride in water is dental fluorosis, where white streaks appear on teeth.
• Some studies show an association between fluoride and harmful health effects, but most of those studies are conducted in areas of the world with exceptionally high fluoride levels, which is not relevant to the U.S., where the fluoride levels in community water supplies are generally low.
• Long-term exposure to very high levels of fluoride can lead to adverse health effects, including noticeable discoloration and pitting of teeth, and skeletal fluorosis, a condition that affects bones and joints. Some studies have also shown an association between high fluoride levels with lower IQ in children.
• Water fluoridation may reduce dental health disparities, especially for children in lower-income households, although more recent studies have been inconclusive.
• The studies consistently identify the consumption of sugary foods and drinks as a leading cause of dental cavities. They highlight how frequent and excessive sugar intake creates an environment in the mouth that favors the growth of bacteria responsible for tooth decay.
• There is a need for more, high-quality research on the cost-effectiveness of water fluoridation and the limitations of previous research to produce more robust evidence for policymakers.

This is a companion piece to 15 common questions about fluoride in drinking water…”