Say Goodbye to Kidney Stones: The Best and Worst Foods for Prevention - Ask a Nutritionist

Transcript:

BRANDY: Welcome to Dishing Up Nutrition's midweek segment called “Ask a Nutritionist”. My name is Brandy Buro. I'm a Licensed and Registered Dietitian here at Nutritional Weight & Wellness. On today's show, I'll be covering a topic that was requested from one of our Dishing Up Nutrition listeners. The topic today is “What's some dietary advice for kidney stones?”

I think this is a great topic. I think it's an underexplored topic here on the show. So, I'm really happy to share what I've learned preparing for this episode and what I've learned just from working with clients one on one. And if you've ever had a kidney stone, you know how painful they can be.

And the clients that I've worked with who have gone through this are very motivated to do whatever they can to prevent it from happening again. So, you're probably listening to this today because you might have a kidney stone, or maybe you've had one in the past and you just don't want to go there again. So this is your episode.

What is a kidney stone?

I just want to get started by discussing what a kidney stone is. So, kidney stones are hard deposits that are made of minerals and salts that are filtered through the kidneys, but when we're not urinating often enough, the urine is so concentrated that those minerals start to stick together and crystallize, and it forms this hard stone like material.

What are some risk factors for developing kidney stones?

So, dehydration, not urinating often enough, will increase your risk of developing these kidney stones. So I will talk a lot about how to stay hydrated because that is rule number one, whether you have a kidney stone or whether you want to prevent a kidney stone. And unfortunately, if you have already had a kidney stone, your risk of developing another kidney stone increases by 50%.

So you'll want to be very diligent in the recommendations that I'm going to share with you today. Other risk factors for developing kidney stones include having diabetes, having metabolic syndrome, so maybe you have diabetes, but also high blood pressure, high cholesterol, you might have midsection weight storage, but also folks with digestive issues, conditions that make it difficult to digest and absorb fat in particular.

So that could be, having your gallbladder removed, having Crohn's disease or ulcerative colitis, or maybe you've had a resection surgery like gastric bypass surgery. So all of those populations are at an increased risk. So this applies to a lot of people.

If you already have a kidney stone, that stone will need to pass through the kidney and out of your body somehow. Hopefully, the kidney stone is small enough that it can pass naturally from the kidney to the bladder and out the ureter, but in some cases, that stone is too big and it needs to be surgically removed.

Hydration is key

So there's really not a lot that you can do once that stone has already formed. It just, it needs to pass and one way to encourage the passing of that stone is to stay hydrated and urinate often enough. So drinking plenty of water is going to help pass that stone. So how much water is enough? Well, a good rule of thumb is about half your body weight in ounces and spread that water evenly throughout the day starting right away in the morning.

So an example would be you know, if there's somebody who's about 160 pounds, they'd want to shoot for about 80 ounces of water a day, and that person may actually need a little more water than that if they're sweating a lot, or if they have loose stools, or if they're working in really dry climates or environments. But use that half your body weight in ounces as your starting point.

If you have the chance to find out what kind of kidney stone you had, that can actually help you develop a plan to prevent more kidney stones from forming. This is pretty common information if you had your kidney stone surgically removed.

Oftentimes they will send that kidney stone out to be analyzed to identify what that stone was made out of. Some people may even get a urine test to figure out what's in their urine as a way to sort of predict what their risk is and what. kind of stone they likely had. The most common type of kidney stone is made out of calcium and oxalate or calcium oxalate stones.

So later in the show, I will provide some recommendations that are specific to this type of kidney stone. Let's say you've already had a kidney stone, and you want to prevent a kidney stone from coming back, or maybe you're just being really proactive and you never want to have a kidney stone. Well, water is still your best friend.

Drink plenty of water throughout the day, be proactive in starting your day out with a big glass of water. Again, half your body weight in ounces is the goal; filtered water is the best. Most people do need 80 to 100 ounces, maybe up to 120 ounces a day in some cases. If that sounds like a lot, you can work up to that. You can gradually increase your water intake by adding another glass a day each week until, you know, in a few weeks, you're eventually to your goal.

Beverages to avoid

And while you're doing this, reflect on what other fluids could be crowding out that water. So if you're drinking soda, if you're drinking a bunch of coffee or energy drinks, or other sweetened drinks like lemonade or sweet tea, this does not contribute to your water goal.

And actually, if you're drinking soda or any sugar sweetened drinks, that's actually going to increase your risk of developing a kidney stone. Soda especially. So, soda is kind of a double whammy because soda contains phosphoric acid and high fructose corn syrup. So, both of these things have been found to increase your risk of developing kidney stones.

Other beverages to limit or avoid would be alcohol. So, avoid alcohol as much as you can. Less is more when it comes to alcohol. And try to limit your caffeine. You know, try to top off at about two cups of coffee or about 200 to 300 milligrams of caffeine a day. Many people do so much better with their water intake when they are limiting their caffeine.

So you can't go wrong with water. If you need a little bit of flavor to jazz your water up, add a little bit of lemon or add a little bit of lime to your water. It does add good flavor and the citric acid in the citrus also has some benefits for preventing kidney stone formation. So that's a win win.

Avoid prepackaged, processed food

Other than fluids, let's talk about some food recommendations. Foods to avoid, foods to focus on to prevent kidney stones. So first of all, you want to focus on real food as much as possible and avoid prepackaged, processed foods as much as you can. Eating this way is going to help you maintain a good amount of sodium, which what I mean to say, it's going to help prevent too much sodium intake.

So high sodium intake tends to result in calcium loss through the urine, and that's going to increase your risk of developing those calcium oxalate stones that we just talked about, the most common type of stone. And consuming too much sodium really isn't much of a concern if you are focusing on real whole foods that you make at home yourself.

Because really the only salt that's in that food is what you add to it. And it's very likely going to be much less than what you find in processed foods. If you are somebody that's eating more prepackaged processed foods, your sodium intake is going to go way up. So those processed foods like canned soup, frozen dinners, bread, condiments, chips, fast food, that's the main source of sodium for most Americans.

Eat protein + vegetables to balance pH

But real food is naturally low in sodium, so you can't go wrong with a real food diet. It's a naturally low sodium diet. It's the best way to keep your sodium intake low. Next, you want to focus on including a variety of vegetables with protein at every meal. Protein plus vegetables will result in a balanced pH or acid level of your urine, and that's going to create the optimal PH to prevent kidney stones from forming.

So you may have heard something about high protein diets increasing your risk of kidney stones. And there is some truth to that. But that risk is reduced significantly when you incorporate lots of vegetables into those meals every day. Diets that are high in protein but low in vegetables can cause your urine to become too acidic and that is sort of the perfect environment for developing a kidney stone.

But when you add vegetables to your protein, that balances the acidity out, which prevents it from becoming too acidic. and prevents stones from forming. So remember that formula, protein plus vegetables equals balanced pH equals less stone formation.

High oxalate foods & when to reduce consumption

I just want to give you a couple notes on those calcium oxalate stones. So if you have a history of calcium oxalate stones, you will want to be very careful about not eating too many fruits and vegetables that are high in oxalates. So, some common oxalate rich foods include spinach and collard greens, rhubarb, beets, quinoa, sesame seeds, chocolate, wheat, and almonds. So, you might be a little worried about hearing that list.

You might have heard some of your favorites, but that doesn't mean you can't ever eat these foods again. It just means don't overdo it. I think it's really helpful to work with a dietitian to figure out a plan that helps you moderate these high oxalate foods.

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So rather than eliminating these foods completely, be mindful of how often you're eating them. How much are you eating them when you have them? So, for example, if you're somebody that has spinach and almond butter in your smoothie every morning, a really great adjustment would be to instead of spinach, switch to kale. Instead of almond butter, switch to peanut butter or canned coconut milk. And that's naturally going to reduce the oxalate content, but you're still enjoying your smoothie. You're not changing much about your routine.

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Calcium’s role in offsetting oxalate absorption

​So we just talked about oxalates. You might be wondering about calcium. How does calcium fit into this equation? Well, there's some interesting news here about calcium. Eating foods with calcium can actually offset how much of that oxalate you absorb. And that can reduce the potential to form your kidney stones.

So calcium actually binds with oxalate in the stomach and in the rest of the digestive tract. So that's going to prevent it from being absorbed. And it's eliminated in the stool, so there's less risk of it going on to form that kidney stone. So, it's actually a benefit to consume some calcium with some of these high oxalate foods, because it can prevent oxalate absorption.

So the most obvious sources of calcium would be dairy products like plain yogurt, cottage cheese, and cheese. These are all great options if you're somebody that tolerates dairy. You do want to try to get the best quality that you can, so full fat, grass fed, organic if you can. If you don't tolerate dairy, and even if you tolerate dairy, there are other foods that are rich in calcium but low in oxalates. So things like bok choy, broccoli, kale, those deep green vegetables high in calcium, low in oxalates with the exception of spinach.

So try to incorporate some of those foods into your meal plan. Another great food source of calcium would be fish that contains the bones because obviously those bones are going to be rich in calcium. My favorite way to do this is canned salmon with the bones retained. You don't even notice them after you cook it. They just kind of melt away. It's kind of magic.

Another good option would be sardines. A lot of people love sardines. So those little fish, those little bones are maintained. So you're getting a good amount of calcium with sardines.

Supplements that can help with kidney stone prevention

So now you might be wondering more about other supplements. Are there other supplements that could be helpful for kidney stone prevention? So calcium is one that I would recommend for those that have a history of calcium oxalate stones.

I do recommend taking a high quality calcium supplement like calcium citrate or MCHC. When you take a little bit of calcium with each meal, again, that's going to bind to the oxalates in the food, prevents its absorption, and prevents the potential to form a kidney stone. The Activated Calcium from Nutrikey would be a great choice. One capsule per meal would be a good strategy to help with that oxalate absorption.

Vitamin D is another one that I would recommend to anyone with a history of kidney stones. Vitamin D deficiency is very common in folks with kidney stones that live in northern latitudes. So the thought is that a vitamin D deficiency could increase your risk of developing kidney stones. So a daily supplement of 2,000 to 5,000 international units would be a great easy step to take to prevent deficiency and reduce your risk.

I always recommend taking vitamin D with something called vitamin K2. There are lots of vitamin D3 supplements that include this as part of the formula. So vitamin K2 actually helps vitamin D transport calcium to your bone. So it's one way you can sort of get some extra insurance that your calcium is getting to the places that you want it to be and not your kidneys.

Omega-3 is another one that I would recommend for just about anybody. Omega-3 fats have been found to be related with reduced calcium and oxalate excretion in the urine. So, I would recommend 2,000 to 3,000 milligrams every day. Or if you prefer, you could eat some fatty fish like salmon, include that into your meal plan a few times a week and you can think of that as your omega-3 supplement.

There is one supplement that I would use caution with. And that is vitamin C. And that's not to say you should never take vitamin C as a supplement, but high doses of vitamin C for long periods of time could increase your risk of calcium oxalate stones. And that's because oxalate is kind of a byproduct of vitamin C getting broken down and metabolized. So the more vitamin C supplements you take, the more oxalate that's floating around.

But I would say a dose of about a thousand milligrams a day is very safe, but if you're doing more than 2,000 milligrams for long periods of time, you might want to adjust that dose or take a break for a little while.

Recap

So let's recap what we have learned today, the big takeaways for dietary strategies for treating and preventing kidney stones. Number one is drink water. Make this your favorite beverage. Sip on this throughout the day, maybe with a slice of lemon or lime, because dehydration will begin the process of developing kidney stones. So you want to be drinking water, you want to be peeing often throughout the day. Water is nonnegotiable.

So you want to aim for half your body weight in ounces every day. And just remember that using the bathroom is a good sign It means that you are flushing out the waste buildup and preventing kidney stones from forming. And we hope that all that water is going to drown out the beverages that can cause kidney stones, like soda, lemonade, sweet tea.

So eliminate those sugar sweetened beverages, especially soda, and avoid alcohol as much as you can. Caffeine is something that you should limit. Think two cups of coffee, two cups of tea a day. And when it comes to food, eat real foods. Avoid processed foods as much as you can. This is a natural way to manage your sodium intake.

And within those real food meals, you want to include a lot of different kinds of vegetables with your protein at every meal. Bonus points if you can make some of that protein fatty fish like salmon. Because you get that benefit of omega-3 fats. And if you have a history of calcium oxalate stones, you will want to be mindful about those oxalate rich foods like spinach, almonds, beets, and rhubarb. So try to limit your intake and vary your vegetables.

And you may want to try a calcium supplement, a high-quality calcium supplement with each meal to offset the oxalate load. And I would say most people could benefit from taking an omega-3 supplement and a vitamin D3 supplement with K2.

That's it for today's episode of Dishing Up Nutrition's “Ask a Nutritionist”. I really hope you enjoyed our episode today and walked away with some strategies to prevent kidney stones. If you liked this episode, leave us a rating or a review on your favorite podcast platform. That way we can help even more people make that connection between what they eat and how they feel. And if you have a question you'd like us to answer, just ask us.

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