Pros and Cons of Water Fluoridation

Most U.S. water supplies are fluoridated to prevent tooth decay. Does this violate the precautionary principle?

Monica Reinagel, MS, LD/N, CNS
4-minute read
Episode #237


Pros and Cons of Water Fluoridation

Should fluoride be added to public water supplies in order to reduce tooth decay? Communities across the U.S. are grappling with this question. In municipalities where they don’t fluoridate the water, citizens are debating whether they should start. Meanwhile, those who live in cities that do fluoridate are debating whether they should stop. Nutrition Diva listener Amanda recently wrote to ask my opinion on this charged issue. Before I weigh in, let me quickly outline the main arguments for and against.

Pros of Fluoridation

Water fluoridation programs date back to the middle of the last century, when the American Medical Association and the American Dental Association both came out in favor of fluoridation as a safe and effective way to reduce cavities and tooth decay in the general population. In fact, the Centers for Disease Control hailed fluoridation as one of the top ten achievements of the twentieth century! The World Health Organization points out that benefits are greatest for the economically disadvantaged, who often don’t have access to adequate dental care.

Cons of Fluoridation

Opponents of fluoridation say too little is known about the long term risks of fluoride ingestion, and point to research suggesting a positive correlation between fluoridation programs and certain types of cancer. Fluoride may also pose a health hazard to people with kidney disease and widespread use of public fluoridation makes it awfully difficult to avoid. They argue that it’s not ethical to dose the entire population with fluoride in order to reach a small subset of the population and that even underprivileged citizens should have the right to opt-in and not be treated without consent.

Is Nutrition Diva For or Against Water Fluoridation?

So, what side of the issue am I on? First, I should point out that, with the exception of a few years I spent in Europe, I have always lived in areas with fluoridated water. I may have gotten some benefit in terms of fewer cavities as a kid, and I’m not aware of having suffered any damage. But whenever you’re talking about public policy, it’s a good idea to consider the precautionary principle. 

What is the Precautionary Principle?


The precautionary principle states that if a proposed action might be harmful but there’s a lack of evidence one way or another, you should attempt to gather more evidence that the action isn’t harmful before proceeding. In other words, you err on the side of caution.

That doesn’t mean that we have to be 100% certain that something is harmless before doing it—because it’s impossible to prove that something is harmless. You can prove that under certain conditions, it failed to produce certain harmful effects. But there’s always the chance that your test conditions didn’t reflect real life, which is always more complex than a research study. Or, perhaps your study just didn’t last long enough to see the harmful effects. It’s also possible for researchers to miss harmful effects that do occur, simply because they aren’t the ones they were looking for. Nonetheless, if you have specific concerns, it should be possible to design studies that either validate or invalidate those concerns.

There are other ways to over-apply the precautionary principle. People sometimes invoke the precautionary principle simply because something is new or unfamiliar to them—or out of a knee-jerk mistrust of science or industry or government. That’s not caution; that’s a prejudice. Random theories or rumors about why something might be harmful are also not sufficient.

However, in the case of fluoridation, I think that the potential for harm is well enough documented to invoke precautionary principle. Granted, the risks may be small. On the other hand, fluoridation of the public water supply seems like an unnecessarily aggressive and invasive way to prevent cavities in medically underserved populations. If this issue were to appear on the ballot where I live, I think I would vote against fluoridation and in favor of more targeted programs to provide dental care and cavity protection to those who need it. And, in fact, that’s what the voters in Portland Oregon decided this month.

How to Manage Your Fluoride Exposure

Most of us, however, still have fluoride in our water. The more water you drink, the more fluoride you get. Personally, although I don’t think cities should fluoridate their unwary citizens, fluoride is not high on my list of things to worry about. I’m not going to change my habits to avoid it—but you may feel differently. If you want to reduce your exposure, you can get a special filter installed in your water line to filter out the fluorine. Reverse osmosis and distillation will also remove fluoride. (Pitcher filters like Brita and Pur will not.)

See also: What’s in your water?

Keep in mind that many bottled beverages are made with fluoridated water. Fluoride is also naturally present in tea leaves and drinking lots of black tea can be a significant source of fluoride exposure. 

Finally, if you live in an area that doesn’t have fluoridated water, you can get the tooth-hardening benefits of fluoride by using fluoride toothpastes or rinses. You and the kids can also get topical fluoride treatments from your dentist. If you cannot afford regular dental care, there are several agencies and organizations that can help you find low or no cost dental care in your area. See “Resources” below for a link.

Keep in Touch

What are your thoughts about fluoridation and/or the precautionary principle? Post your comments and questions below or on my Nutrition Diva Facebook Page. I answer a lot of listener questions in my free weekly newsletter, so if you’ve sent a question my way, be sure you’re signed up to receive that.


Cancer Incidence and Water Fluoridation (Journal of Epidemiology)

Tap Water image from Shutterstock

About the Author

Monica Reinagel, MS, LD/N, CNS

Monica Reinagel is a board-certified licensed nutritionist, author, and the creator of one of iTunes' most highly ranked health and fitness podcasts. Her advice is regularly featured on the TODAY show, Dr. Oz, NPR, and in the nation's leading newspapers, magazines, and websites. Do you have a nutrition question? Call the Nutrition Diva listener line at 443-961-6206. Your question could be featured on the show.