Tips for Preventing Kidney Stones

Kidney stones are common in the United States, with about 11% of men and 9% of women reporting ever having had a kidney stone. Once you get a stone, you are at risk of getting another. Fortunately, it is possible to prevent kidney stones from forming by paying attention to your diet and remaining well-hydrated.

What Are Kidney Stones?

The kidneys are two bean-shaped organs located in your upper abdomen, under the ribs towards your back. The kidneys’ function is to filter your blood by removing waste products, balancing fluid levels, and keeping electrolyte levels in check. Stones form in the kidneys when there is an excess of certain products within the urine or if there is not enough fluid passing through the urine (i.e., dehydration).

Kidney stones can be as small as a grain of sand or as large as a golf ball (though stones that large are rare). They can remain in the kidney and cause no problems or increase risks for infection. Pain can start when the stone starts moving from the kidney into the ureter, which connects the kidney to the bladder. When these stones pass through the relatively narrow ureter, they can cause pain, bleeding, infection, nausea, vomiting, fever, and chills. Smaller kidney stones can pass on their own, but larger ones usually require surgery to remove.

There are five main types of stones: calcium oxalate (the most common), calcium phosphate, uric acid, struvite, and cystine. Here’s what you can do to prevent calcium oxalate stones from forming.

Stay Hydrated

Getting enough fluid is vital for stone prevention. Without enough water, urine becomes more concentrated, potentially leading to stone formation. On the other hand, sugary drinks, such as soda and sugar-sweetened juices, can increase the risk of forming stones. Cola can further promote kidney stones because they contain phosphoric acid. Stick to water and even water-dense foods like cucumbers and watermelon.

Drink a minimum of eight to 10 glasses of water a day. Increase this amount if you are active, sweating more, or live in hotter climates. (Bonus tip: add a squeeze of lemon to your water; potassium citrate found in lemons can help protect against stones.)

Try to limit your coffee or other caffeinated beverage to three cups a day, as too much caffeine can dehydrate your body. If you like tea then stick with green tea over black tea; green tea has less oxalate which can increase stones.

Balance Your Protein With Fruits and Veggies

Studies suggest that people whose diet is high in fruits and vegetables tend to have a lower incidence of kidney stones. One reason may be that animal protein makes the urine more acidic, which can contribute to stones. Note: You don’t have to give up meat to prevent kidney stones. Rather, balance out the acidity by eating lots of alkaline-forming fruits and veggies.

Get Moderate Amounts of Calcium

Even though most kidney stones consist of calcium oxalate, this does not mean you should avoid calcium. Calcium is important for bone strength. You should still get your daily recommended amount of calcium. Stones form when calcium binds to oxalate. You can prevent this from happening by drinking enough fluids to avoid concentrating these minerals in your urine, or decrease the amount of oxalate in your diet.

Reduce Oxalate-Rich Foods

Reducing foods high in oxalates can help bring down the amount of oxalate in your kidney. Foods with high oxalate include, but are not limited to, spinach, rhubarb, rice bran, almonds, cashews, cocoa powder, black tea, tofu, and sweet potatoes.

Minimize Your Sodium

High levels of sodium in the diet can increase the risk of kidney stones. In the typical American diet, most sodium comes from processed foods. You can limit your sodium intake substantially simply by switching to unprocessed, whole foods. That alone can greatly decrease the amount of oxalate and calcium in the urine and therefore reduce your risk of stones.

Ditch the Yo-Yo Diets

Large meals and binge eating, especially at night, can lead to very concentrated urine. Further, yo-yo dieting repeatedly breaks down stored body fat, which creates metabolic by-products that must filter through the kidneys. These by-products tend to make the urine more acidic, which can lead to stones.

Meanwhile, low-carb, high-fat/protein diets can increase urinary acidity, lower urinary citrate, and raise urinary calcium, all of which can contribute to kidney stone formation. By now you might have noticed that all these tips are basic principles of a healthy diet. They probably even sound like good old common sense. And it’s true: even if you’re not at risk for kidney stones, a balanced whole food diet with lots of water will serve you well.