Skip to main content
Is Fluoride in Drinking Water Bad?

You are listening to Health Library:

Is Fluoride in Drinking Water Bad?

Dec 07, 2018

There are some people that say fluoride is bad for you, but is it? In the past 50 years, many studies have shown that fluoride in drinking water is beneficial and that a small amount in the water helps children have healthy teeth. Dr. David Okano stops by to share what fluoride is and how it can affect us.

Episode Transcript

Interviewer: Fluoride in your drinking water. Is it bad? We're going to find out the real deal next on The Scope.

Announcer: Health information from expects, supported by research. From University of Utah Health, this is

Interviewer: There are some people that say fluoride is bad for us as humans and it shouldn't be in our toothpaste or in our water. Now, the thing that I struggle with, is that if it was really that dangerous, why would we still be doing it? And I wanted to find out from an expert. Dr. David Okano is a periodontist with 30 years of experience and is currently an assistant professor at University of Utah School of Dentistry. So help me sort through this. Have you had to have this conversation with a patient that is very concerned about the fluoride in the water or their toothpaste and being poison the body?

Dr. Okano: That's a question that all dentists are asked about on a regular basis, dental hygienists also. We've known for over 50 years that fluoride has a very beneficial effect to the developing tooth and the areas that had naturally-occurring fluoride were areas where it was found that they had very strong teeth, very few cavities, very few fillings were necessary in those areas. And as a result of those regions having naturally-occurring fluoride, teeth were very strong. It was found that by adding fluoride into the municipal water supply, that the developing tooth in children, in the child, could then benefit by becoming stronger and much less susceptible to tooth decay.

Interviewer: So there's research that shows this?

Dr. Okano: Absolutely. At a very small amount, the fluoride is very beneficial. And that's when you get your best benefit from fluoride in water is if you're a child with a developing tooth that will become strong for the rest of their adult life.

Interviewer: Okay. So when you go on the Internet and you do some research on fluoride in water and you find those there are those that are against it, they say that it is poisonous, they point to the back of the toothpaste tube and it says don't swallow because there is fluoride. They point to a study from the Harvard School of Public Health that talks about how it can cause a reduction in IQ points. Help me sort through . . . that doesn't feel right. Help me sort through what's going on here.

Dr. Okano: You're correct. "That doesn't feel right," is a good way to say that. The studies have indicated a lot of bias in many instances. The sample sizes have been of concern. Really, the locations where these studies have been conducted we really can't relate to the American system. So the fluorides we have known at a very low concentration . . . in fact, the American dental association has reduced the amount of concentration that's recommended in drinking water for fluoride. Too much of anything is not good.

We have chlorine added to the municipal water supply already. Too much chlorine there can be a real problem, and has been in some cases, but there are a lot of safeguards in the water systems to prevent excessive amounts of fluoride from accidentally being placed into your water supply.

Interviewer: From what I understand, that's what a lot of these studies are talking about, are locations where it was a large amount, beyond what was safe.

Dr. Okano: That is correct.

Interviewer: And we have a very good idea, based on research, what is safe.

Dr. Okano: Yes, very much so. We have 50 years of data showing the benefits of fluoride. And if you look at the children, especially in communities that do not have fluoride, and the challenges they have with tooth decay, and the concerns they develop because of their fears of dentistry, and you look at other children who do not have decay and what great experiences they have in the dental setting, it's remarkable what the benefit of fluoride has been for those 50 years.

Interviewer: And I think a lot of times when you look at a lot of things in life, it's risk-benefit. It's that risk-benefit balance.

Dr. Okano: Absolutely. The benefits are substantial for having fluoride in your water supply. My daughter is a Ph.D. candidate in public health and she has mentioned to me that fluoridation in water has been one of the top five community health benefits in public health, the first being indoor plumbing, the second being antibiotics for infectious disease, and I believe she told me fluoride in the water supply was the number three best benefit that has ever been done for public health.

Interviewer: That's pretty good for fluoride. That's quite a list, indoor plumbing and antibiotics, right, and fluoride is number three. In good company. So if you've had conversations with patients before that have raised concerns, generally, after they have the talk that we just had, does it kind of alleviate those?

Dr. Okano: Generally speaking, it does. They recognize the fluoride that's been placed into the municipal water supply or the fluoride in your toothpaste is of such low concentration that it's not dangerous and the benefits are great. Nonetheless, there are some folks who do not believe in it and they are skeptics for the rest of their lives. But we can't convince those folks. But for the masses, where so many people have benefited, people understand the benefits of fluoride to their dental health.

Interviewer: And I think the interesting thing that you said is that it's a naturally-occurring element or chemical in a lot of water and it hasn't affected us. It's just those high concentrations that, really, you've got to watch out for.

Dr. Okano: That is correct.

Announcer: Have a question about a medical procedure? Want to learn more about a health condition? With over 2,000 interviews with our physicians and specialists, there’s a pretty good chance you’ll find what you want to know. Check it out at

updated: December 7, 2018
originally published: July 13, 2016