Is fluoride a toxic chemical that is neither safe or effective at preventing tooth decay? No, that's not true: In the right concentrations fluoride is a safe and effective tool for preventing tooth decay, although overexposure to high levels of the mineral has been linked to some health issues, according to U.S. health agencies. Fluoride in U.S. public water systems has been considered safe for more than 75 years.
The claim appeared on Facebook on January 9, 2023, in a reel that features a woman wearing a tall tin foil hat who talks about the alleged harmful effects of fluoride in drinking water. It opened:
We have been lied to about fluoride. It is an extremely toxic chemical that I believe we should not be drinking, cooking, or showering with. Here's why. Fluoride was added to our water more than 70 years ago based off inaccurate and misleading studies that claim that fluoride promotes strong and healthy teeth but we now have substantial evidence showing that fluoride is neither safe or effective at preventing tooth decay.
Here's how the Facebook post appeared on the day of this writing:
(Source: Facebook screenshot taken Fri Jan 26 at 17: 49:47 2023 UTC)
Fluoride is a natural mineral, and sodium fluoride, which is what's added to water systems, is the inorganic salt of fluoride. Fluoridated water is not only safe to drink, but prevents cavities, according to the Centers for Disease Control and Prevention (CDC).
Fluoride works by accelerating the buildup of healthy minerals in tooth enamel, making the enamel harder and more resistant to the action of acids from food and drink. Studies have shown that fluoride slows, and in some cases can reverse, tooth decay, by remineralizing, or rebuilding weakened enamel.
Fluoride was first added to a U.S. public water system in Grand Rapids, Michigan, in 1945 where it was shown among children to produce a dramatic drop in dental caries, the bacterial infections that cause tooth decay.
Since then, community water fluoridation has been adopted across the country and is considered one of the most important achievements in public health.
According to the most recent data from the CDC, as of 2018, more than 200 million people, or 73.0 percent of the U.S. population served by public water supplies, had access to water with fluoride levels that prevent tooth decay.
In 2015, scientists for the U.S. Public Health Service set new recommendations for the optimal amount of fluoride in public water systems at .07 milligrams per liter. The amount provides enough fluoride to prevent tooth decay in adults and children, while limiting the risk of dental fluorosis, an unwanted health effect of fluoridated water. Fluorosis is a cosmetic condition that leaves the teeth discolored as a result of overexposure to fluoride early in life.
As with many substances, exposure to fluoride in small amounts, such as the level found in drinking water, is beneficial, while overexposure to high levels of the mineral can create or affect health problems. According to the World Health Organization, exposure to fluoride at a level of 6 milligrams per day can trigger progressive stiffness and pain in the joints over many years. High-level or long-term exposure has also been linked to some skin and high blood pressure issues, as well as thyroid conditions.
The CDC has a portal introducing basics about Community Water Fluoridation with links to more in-depth articles and FAQs.