Does Your “Filtered” Water Still Have Fluoride?

Summary

Chasing Life Podcast Episode: "Does Your 'Filtered' Water Still Have Fluoride?"

Release Date: June 10, 2025

In this informative episode of CNN's "Chasing Life," host Dr. Sanjay Gupta addresses pressing health concerns about fluoride in drinking water and its alternatives. Additionally, he explores the best dietary practices to maintain cognitive health as we age, providing listeners with actionable insights to enhance their well-being.

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1. Understanding Fluoride in Filtered Water

Listener's Question: Paula from West Springfield, Massachusetts, asks whether the filtered water from her refrigerator removes fluoride.

Dr. Sanjay Gupta's Response: "Most water filters are not going to remove fluoride." (01:26)

Dr. Gupta explains that fluoride, being a dissolved mineral, is notoriously difficult to eliminate with standard water filters. However, he highlights two effective methods:

• Reverse Osmosis Filters: These systems force water through a semi-permeable membrane, removing approximately 80-90% of fluoride.

• Distillation Filters: By boiling water and capturing the steam, distillation effectively removes nearly 100% of fluoride.

He reassures listeners by stating, "For most people living in the United States, this is not a concern." (02:50) Dr. Gupta emphasizes that fluoride levels in U.S. water supplies are typically within safe limits and encourages listeners to verify their local fluoride levels through consumer confidence reports or the CDC's website.

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2. The Role of Fluoride in Dental Health

Listener's Question: Lucia from New York inquires if using fluoridated toothpaste or mouthwash is sufficient for dental protection, especially if fluoride is removed from drinking water.

Dr. Sanjay Gupta's Response: "Fluoridated toothpaste or rinses are really effective at protecting teeth." (03:38)

Dr. Gupta acknowledges the historical significance of water fluoridation as a major public health achievement that has significantly reduced dental cavities. However, he notes a decline in its incremental benefits since the advent of fluoridated toothpaste and improved dental care access.

Key Points:

• Proper Usage: For children under three, a rice-grain-sized amount of toothpaste is recommended, while adults should use a pea-sized amount.

• Brushing Technique: Allowing fluoride to remain on the teeth without rinsing for 10-15 minutes enhances remineralization.

Dr. Gupta warns about potential consequences of removing fluoride from water: "There have been some modeling studies... if you remove fluoride from the water, it would lead to about 25 million excess cavities over the next five years." (05:15) He underscores the importance of balancing fluoride sources to maintain dental health.

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3. Nourishing the Brain: Best Foods for Cognitive Health

Listener's Question: Sam from Norwalk, Connecticut, seeks advice on the best foods to enhance brain health, memory, and cognitive functions.

Dr. Sanjay Gupta's Response: "There is some solid science behind certain foods that support memory and cognition." (08:15)

Dr. Gupta references insights from Dr. Uma Naidu, a nutritional psychiatrist, highlighting key dietary components that bolster brain health.

Dr. Uma Naidu's Recommendations:

• Omega-3 Fatty Acids: Found in oily fish like salmon, tuna, and mackerel, essential for brain protection.

• Olive Oil: Rich in healthy fats that support cognitive functions.

• Herbs and Spices: Turmeric (with black pepper for enhanced absorption), cinnamon, saffron, rosemary, ginger, and sage have been shown to improve memory and thinking skills.

• Caffeine in Moderation: Helps with focus and memory when consumed responsibly.

Additional Insights from Dr. Gupta:

• Blueberries and Leafy Greens: Studies indicate that regular consumption can slow cognitive decline. Specifically, "Just a handful of blueberries or a single serving of spinach or kale can slow cognitive decline by years even." (10:27)

• Eggs: Packed with choline, a nutrient vital for memory and learning.

• Balanced Meals: Combining these ingredients into tasty meals ensures that nutrients are bioavailable and effectively utilized by the body.

Dr. Gupta emphasizes the importance of integrating these foods into daily meals to maintain and enhance brain health over time.

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4. Conclusion and Final Thoughts

Dr. Gupta wraps up the episode by encouraging listeners to stay informed and proactive about their health choices. He invites further questions and interactions through various channels, reinforcing the podcast's commitment to providing reliable health information.

"If there's something health related you've been wondering about, you can record a voice memo, email it to asksanjayn.com or give us a call." (12:15)

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Production Credits: Chasing Life is produced by CNN Audio with a dedicated team including Aaron Mathewson, Jennifer Lai, Grace Walker, and others, ensuring high-quality and informative content for its audience.

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This episode of "Chasing Life" offers valuable insights into managing fluoride intake and emphasizes the significance of a brain-healthy diet. Whether you're concerned about your drinking water or looking to enhance your cognitive functions, Dr. Gupta provides evidence-based advice to help you lead a healthier, more informed life.

Transcript

[Carl Zimmer]

Chasing Life is supported by the World as yous'll Know It, a podcast about the forces shaping the future. In this season, host and science journalist Carl Zimmer speaks to some of the most respected scientists in the field of aging research about the massive changes in human longevity and what comes next. Is our lifespan set or will a breakthrough add decades to our lives? Can older brains be rewired to function like younger ones? Which so called biohacks actually work? The world as you'll know it is available now.

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[Dr. Sanjay Gupta]

Welcome to paging Dr. Gupta. One of my favorite times of the week. I really love hearing from you. You know, we've been doing this for a couple of months now. I love reading your questions. Hearing your questions gives me an idea of what's on your mind, whether it's something in the headlines, sometimes it's something happening in your own life. I'm here to help try and break it down. And we've got a great first question lined up. Kira, want to do the honors?

[Kira Dehring]

Absolutely. So Paula in West Springfield, Massachusetts asks, in our household, we use filtered water coming out of the refrigerator and does that eliminate the fluoride in the water?

[Dr. Sanjay Gupta]

Okay, Paula, this is a great question. There's been a lot of news about fluoride lately. So let me give you a simple answer and then explain it. Most water filters are not going to remove fluoride. Keep in mind that fluoride is a mineral and it dissolves in the water. So it's actually quite hard to remove to filter out. Most conventional filters are not going to do this. Now there are a couple of ways to filter out fluoride. One is using something known as reverse osmosis. A reverse osmosis filter. This essentially is forcing the fluoridated water under pressure through a semi permeable membrane. Reverse osmosis is about 80 to 90% effective at removing fluoride. Another type is distillation, a distilling filter. Now this essentially is boiling the fluoridated water and then capturing the water vapor, that steam that gets produced, and leaving the fluoride behind. And that's nearly 100% effective. Now again, I know there's a lot of discussion about fluoride lately, but two things I just want to make sure, you know, in most places around the country around the United States, fluoride is not going to be at a level that is high enough for concern. So despite the fact that we're talking about it a lot lately, there really isn't a lot of cause for concern. Second thing, there are ways to sort of figure out how much fluoride is in your water. There is something called a consumer confidence report that you can get from your water company. They're obligated to give it to you if you ask for it. That can tell you how much fluoride is in your water. You can also go to the CDC's website and look for my waters fluoride and plug in where you live. That can also give you an idea of how much fluoride's in your water. But again, Paula, I just want to be clear. For most people living in the United States, this is not a concern.

[Kira Dehring]

Okay, wait. Now, Sanjay, let's just say the fluoride is removed from the drinking water. We have a question from a listener named Lucia in New York who wants to know if brushing her teeth with a fluoridated toothpaste or rinsing with a fluoridated mouthwash is is that enough to protect her teeth?

[Dr. Sanjay Gupta]

Okay. Yes. This is a great question. The short answer here is yes. Fluoridated toothpaste or rinses are really effective at protecting teeth. One thing I just want to point out, if you look at the sort of overall impact of fluoridating water, the public health community often refers to that as one of the greatest public health achievements over the last century. And for good reason. It's made a huge impact. But at the same time, really, since about 1975, the incremental benefit of fluoride in the water has gone considerably down. Why is that? Because around that time 50 years ago, we started to have fluoridated toothpaste and more widespread access to dental care. So fluoridated toothpaste can make a huge difference. When you think about fluoridated toothpaste. First of all, for children under the age of three, you don't need very much toothpaste. About a rice grain size amount of toothpaste is good. For children under the age of three, that's not very much. And for adults, about a pea size amount of fluoridated toothpaste. When you're thinking about the fluoride, you want to make sure that it's sort of sticking to your teeth and you don't want to rinse your teeth for a period of time after you brush your teeth. Just let that fluoride sit on your teeth. That's what allows it to sort of cause remineralization. Don't eat for 10 to 15 minutes afterward either. So no doubt then that brushing your teeth with a little bit of fluoridated toothpaste can make a huge difference. Now, I will say that the impact of taking fluoride out of the water is a little bit hard to know. There have been some modeling studies. One came from a group of researchers at Harvard that basically predicted that over the next five years if you remove fluoride from the water, it would lead to about 25 million excess cavities. Over 10 years, it would lead to about 54 million excess cavities. Cavities being defined by something that needs a filling. So again, fluoridated toothpaste, fluoride rinses, they do a great job, but there's an impact as well at taking the fluoride out of the water. Okay, we're going to take a quick break, but when we come back we're going to talk about foods to eat to keep your mind sharp. Stay with us.

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[Dr. Sanjay Gupta]

Alright, I know that sound Kira, who's up next?

[Kira Dehring]

Next up is Sam from Connecticut, and he has a question I think you're going to love about brain food. Take a listen.

[Sam]

Hi, my name is Sam and I'm 68 in Norwalk, Connecticut. I don't know if you've covered this in one of the podcasts that maybe I've missed, but I'd like to know what are the best foods you could eat to nourish your brain? Memory, response time, accuracy. Thanks. Have a great day and thank you for all the wonderful information. Bye.

[Dr. Sanjay Gupta]

Okay, Sam, thank you for your question. And I do love the fact that you're thinking about how to keep your brain sharp. As you know, I'm a neurosurgeon. I think about the brain all the time. The most enigmatic three and a half pounds of tissue in the known universe. Now, with regard to how we nourish ourselves and its relationship to. To brain health, there is some solid science behind certain foods that support memory and cognition. In fact, I sat down on a previous episode of chasing life with Dr. Uma Naidu. She's a nutritional psychiatrist, by the way. How cool is that? A nutritional psychiatrist. She's also a professional chef and she really digs deep into how food affects the brain. Listen to what she told me.

[Dr. Uma Naidu]

Foods that will help cognition, we actually go back to those, those omega 3s. It's, it's a group that's featured very frequently. Olive oil, also one that we lean into. The herbs and spices that showed up doing well for cognition and for thinking and for memory. And turmeric with that pinch of black pepper, which makes it much more bioavailable. Cinnamon, saffron, rosemary, ginger, sage.

[Dr. Sanjay Gupta]

I hope you caught that last part. It's not only the specific foods, but also these added spices which can make the foods much more bioavailable. If you eat foods that are good for you, but they're not highly bioavailable, that means they're not circulating around the body and the brain and doing their job. Now, Dr. Naidu also gave us some great advice on caffeine and how, in moderation, it can actually help objectively with focus and memory.

[Dr. Uma Naidu]

Coffee was thought if you keep your caffeine consumption or your coffee consumption under 400mg a day, it was thought to be healthy.

[Dr. Sanjay Gupta]

Now, I think it's important to point out that Dr. Naidu's not just talking about these things as individual ingredients. Oftentimes we think of medicines as these single molecules, but. But when it comes to food, it's really about putting all these ingredients together into a meal that is tasty but also brain healthy.

[Dr. Uma Naidu]

You know, for me, this is some guidance. While I know that those foods have been identified as healthy, it's also part of an overall plate, right? It's not just eating the nuts or eating the olive oil. It's putting that together in a meal that's still tasty makes a very big difference to balancing that up for people.

[Dr. Sanjay Gupta]

Beyond that, let me give you some of my thoughts on what the research shows about food and brain health. Studies have shown that eating just a handful of blueberries or a single serving of spinach or kale can slow cognitive decline by years even. There was this big study that tracked over 16,000 older women for 15 years and found that just a half a cup of blueberries or a cup of strawberries a week slowed memory loss by two and a half years. Another study found those who ate a serving of leafy greens, spinach, kale, collard greens, arugula, appeared many years younger in terms of their overall cognitive health compared with those who rarely or never consumed green leafy vegetables. Another one to add to the oily fish, salmon, tuna, mackerel, herring, trout, sardines, they are all rich in something known as dha. DHA is a fat that can help protect your brain. And then there was a study showing that eating fish just once a week was associated with slower cognitive decline and a lower risk of Alzheimer's. You know, I also want to mention eggs. They are packed with something known as choline, which is a key nutrient for memory and learning that many people just don't get enough of. Eggs can be a great source. So Sam, if you're at the store, think about these foods. Look for color in your foods. Berries, greens, those brain Boosting spices Dr. Naidoo mentioned turmeric, cinnamon, saffron, rosemary, ginger, sage. And don't forget your salmon. That's a big one. But remember again, it's about building meals around these components. Make them tasty and pack them with these ingredients. That's a great way to support your brain health over time. All right, that's all the time we have for today and thank you to everyone who sent in questions. I love hearing what you're curious about. If there's something health related you've been wondering about, you can record a voice memo, email it to asksanjayn.com or give us a call. 470-396-0832. Leave a message. Thanks for listening and I'll be back next Tuesday.

[Production Team]

Chasing Life is a production of CNN Audio. Our podcast is produced by Aaron Mathewson, Jennifer Lai, Grace Walker, Lori Gallaretta, Jesse Remedios, Sophia Sanchez and Kira Dehring. Andrea Cain is our medical writer. Our senior producer is Dan Bloom. Amanda Seeley is our showrunner, Dan Dijiula is our technical director and the executive producer of CNN Audio is Steve Lichtai.

[Dr. Sanjay Gupta]

With support from Jamis Andrest, John Dianora, Haley Thomas, Alex Manasseri, Robert Mathers, Lainey Steinhardt, Nicole Pessarou and Lisa Namorow. Special thanks to Ben Tinker and Nadia Kanang of CNN Health and Wendy Brundage.