“Does drinking soda cause kidney stones?”

In this episode, Jeff Sarris and Jill Harris discuss the relationship between soda consumption and kidney stones. They explore the importance of fluid intake, the types of beverages that can contribute to kidney stone formation, and the role of sugar and phosphoric acid in urine acidity. Jill emphasizes that while all fluids count towards hydration, water is the best choice, and she provides insights on how to enjoy sodas in moderation without increasing kidney stone risk.

Takeaways

• Drinking enough fluids is essential to prevent kidney stones.
• All fluids count, but water is the best option.
• Regular sodas contain high amounts of sugar, which can increase kidney stone risk.
• Brown sodas contain phosphoric acid, which can acidify urine and promote stone formation.
• Moderation is key; enjoying soda occasionally is acceptable if balanced with a healthy diet.
• Diet sodas can be a better alternative to regular sodas if sugar intake is a concern.
• Fruits and vegetables can contribute to hydration and help prevent kidney stones.
• Lowering salt and sugar intake can help increase urine output.
• Understanding individual dietary preferences is important for compliance with dietary changes.
• Maintaining a balanced diet can lead to weight loss and improved health.

00:00 Soda and Kidney Stones: An Introduction
02:13 Understanding Fluid Intake and Kidney Health
05:19 The Impact of Sugar on Kidney Stones
08:11 Brown vs. Clear Sodas: What You Need to Know
11:16 Alternatives to Soda: Healthier Choices

Jeff Sarris (00:00):
Does drinking soda cause kidney stones? Let’s talk about that.

So today we’re talking about soda and kidney stones. We have a question I’m gonna read off real quick and we’ll dive right in: “Very often I see people claiming that if you drink soda or other drinks instead of water, you will get kidney stones down the road. Is this true? From my understanding, I thought that drinking two liters of liquid every day was a good way to combat kidney stones, irrespective of whether that liquid is water or something else. I drink a lot of flavored sparkling water, so I was curious about this.”

Jill Harris (00:36):
Yeah, it’s a great question. Let’s break it down. My advice to everybody is you need to drink enough fluids to produce 2.5 liters of urine at least. That’s the minimum a day. And there’s research on all of this at my mentor site, Dr. Fred Coe at kidneystone.uchicago.edu. So much research there.

All fluids count. Water is best. This is what I have said for decades. All fluids count. Water is best. So people will pick apart my drink advice. “Well, what about milk? What about juice? What about soda? What about lemonade? What about whatever?” Fill in the blank. All of it counts, but there’s a lot of fluids that are better than others. I also have an article at Dr. Coe’s site, “A Thirst for Variety,” at kidneystone.uchicago.edu.

Specifically, you may hear your doctor say, “Stay away from the brown sodas, but the clear ones are fine.” I don’t love that advice. The clear sodas—7 Up, Sprite, things like that—they have a lot of sugar. Whether you’re drinking brown soda or clear soda, they all have a lot of sugar typically.

Regular sodas, not diet sodas, have about 38 grams of sugar in one can. Why do we care about sugar? Number one, the more sugar you eat—think added sugar, not fruit. Fruit came with sugar. I’m talking about a product that was made and sugar was put into it. When we have too much added sugar, we will pee less, so we’ll put out less urine output, and our urine calcium may rise. Too much calcium in the urine can increase your stone risk and of course osteopenia and osteoporosis.

Now, if you say to me, “Jill, I want a Sprite here and there,” enjoy, of course. And yes, that does count to your total volume of fluids, but it also comes with some issues. Again, it could be pulling calcium out of your bone, dumping it into the urine. It could make you pee less. So I would not drink any sugared soda.

Now, what is it about the brown sodas? Why do doctors say stay away from those? Well, brown sodas typically contain phosphoric acid, and that additive can acidify your urine, which means it can make your urine pH lower. Who cares, Jill? A low urine pH and acidic urine pH—these are the same things—calcium oxalate crystals and uric acid crystals love that environment. So they are more apt to grow in that environment for people who make kidney stones. That is why your doctors are saying stay away from the brown sodas. I’m going to tell you stay away from all soda because of the sugar. It’s one of the worst foods or drinks that you can have because it’s just all sugar.

Now, as I always say, if this is something you’ve got to have once a week, a couple times a week, please enjoy it. Because if you don’t get to have your favorite things, you’re likely to give up. I get people that give me a hard time about this: “Why are you telling people they can have soda?” I’m very clear on what I say.

I have one patient, a wonderful woman I’ve known for a very long time. She’s in her 80s and she has a soda a week. What am I going to tell her in her 80s? “What are you nuts having that soda every week?” It brings her so much joy. She’s so compliant in everything else. I’m going to say, “Of course you can have that soda. Enjoy it.” When we’re able to have our favorite things here and there, our cravings don’t get a hold of us, and we don’t just say, “To hell with this, I can’t do it.” We have it, we move on, we get right back on track. Nobody makes a stone when they have that kind of lifestyle.

Brown sodas are one of the worst things you could do for overall health if you’re having five sodas a day—and I have patients that have done that. They’re just not the greatest thing for you. They’re just so high in sugar. The brown sodas have phosphoric acid which is acidifying your urine, and that creates a great environment for uric acid and calcium oxalate stones to grow. You can have the clear sodas, but again, they have a lot of sugar.

So if I were you, I would maybe have the diet sodas. At least you get rid of the sugar as far as the clear sodas go. And don’t have them every single day.

This is very specific: When I’m doing private consultations on the phone, I assess each person. If someone says to me, “If I don’t have a diet soda every day, I can’t do this,” I’m gonna say, “Have the diet soda,” because they’re willing to get rid of candy and cookies and cake. They just want that diet soda. I’m going to say keep it. Please keep it.

But if they tell me, “Well, Jill, if I have one diet soda, I’m going to want 10,” I’m going to say that you can’t do. So it just depends. This is why we need to talk to people to find out how important things are to them. If they think they can’t have it at all, they may just give up. If they say, “I could have one a day, I’m willing to do that,” great.

Is it a trigger food for them? Maybe it is. Maybe you say you could have two a day for now and wean yourself off. You’ll be surprised how fast you can wean yourself off things. Also, remember, these patients are coming to me because they had “the worst pain of their life.” They’re willing to give up their first born! So most people tend to be very compliant. Plus, you’ll save some calories. People say all the time, “I’m doing the kidney stone diet, I’ve lost so much weight.” It’s not a miracle—you’re lowering sugar, you’re lowering salt, you’re eating healthier.

Now the other thing: if you’re struggling with water, don’t forget you can eat your water too. Fruits and vegetables are filled with fluids. My vegans and vegetarians, they get rid of the highest oxalate foods, but they can pee more than people that don’t eat veggies, simply because veggies and fruits are so high in water. It’s just another great way to get more fluids into your body so you can pee more.

The number one thing, folks, is the more you pee, the less saturated your urine is with these crystals. You’re peeing these crystals out on a continuous basis. They don’t sit in your kidney. I’ve said it a million times, they’re like little magnets looking for each other. So the more you’re able to pee them out, the less likely you are to make new kidney stones. That’s first and foremost.

Next, I say there are six goals to the kidney stone diet. The next thing you should work on is salt. Lowering salt and sugar will make you pee more. Some of you are drinking six glasses a day and you’re just teetering on the edge of not peeing enough. But if you lower your salt and sugar, you’re going to pee more that way.

So all of these things help you produce more urine. The more urine that leaves your body carrying these crystals away, the less likely you are to make new kidney stones. It’s super important.

So brown soda—not a fan of it. If you need one once a week, please have that. That’s fine. No one’s making a stone with that. But the brown sodas are high in phosphoric acid. It’s acidifying your urine, and that’s putting you more at risk for kidney stones along with all the sugar it has in it. Increased urine calcium will make you pee less. Those are the reasons you should not be drinking brown soda or any sodas on a regular basis. That’s it.

Jeff Sarris (10:36):
Yeah. And for anyone who doesn’t like diet, for example, I really liked the Liquid Death sodas. I don’t know if you’ve tried them yet, but they have cola, they have a Dr. Pepper called “Dr. Death,” they have lemon lime. This isn’t sponsored by Liquid Death or anything, but they’re two grams of sugar in one can, 10 calories.

Jill Harris (10:44):
What’s the sodium? Turn it around and look at the sodium.

Jeff Sarris (10:57):
The sodium in it is actually zero. Isn’t that wild? They use agave nectar and stevia. I don’t love stevia normally, but the flavor—I don’t drink it very much. I had one yesterday though, and it’s nice to have that little change of pace sometimes.

Jill Harris (11:07):
Very good! Jeff, that’s such an important point and I’m glad you brought it up. I don’t know what I would do without you. This is what people are complaining about. That’s why these questions are asked: “I can’t drink water all day long. I need something else.”

So yes, you can have alternatives, and I think this particular question mentioned they were drinking sparkling waters. As long as the salt and sugar are low in those sparkling waters, please enjoy them. We all need a break. I get it. We all need a break from just water.

I will go on record by saying all fluids count, water is best. Those of you who are also drinking milk or plant milks, all that is included in your daily fluid count too. So don’t forget that. That counts.

Jeff Sarris (11:59):
Yeah, absolutely. Hopefully this was helpful. If you liked this video or podcast, thumbs up, leave a comment, send it to a friend, and you can dive deep into all the Kidney Stone Diet goals at kidneystonediet.com. They’re right there on the site. So everything that you possibly need, you can find there and sign up for the email newsletter to get a little inspiration every weekend in your inbox. But with that, I think we’re at it for this week and we’ll see you next time.

Jill Harris (12:24):
Bye everybody, thank you.