Written by Jill L. Jaimes, MD | Reviewed by Katie E. Golden, MD
Key takeaways:
Kidney stones are painful. And once you get one, your risk of getting another one is higher. But there are dietary changes that can help prevent kidney stones.
Limiting certain substances in your diet can help you avoid another kidney stone.
Eating other foods and supplements may help reduce your chances of getting a kidney stone.
An older adult drinks coffee while at their computer.Zorica Nastasic/E+ via Getty Images
If you’ve ever had a kidney stone, you know they can be pretty painful. And 1 in 2 people who have a kidney stone will have another one within 5 years. The good news is that small changes to your diet can help you lower your risk of getting kidney stones. We’ll talk about foods that cause a kidney stone and foods that may help prevent them.
How is diet related to kidney stones?
Most of the minerals in your body come from the foods you eat. When certain mineral levels in your blood become high, they can clump together in your kidneys as they filter those minerals out of the blood. And this clump can form into a kidney stone.
There are several different types of kidney stones. Each type is affected by your diet in different ways. These include:
Calcium stones: These are the most common type of kidney stones. And there are two types: calcium oxalate (more common) and calcium phosphate.
Uric acid stones: This type is more likely to form when your urine is acidic.
Cystine stones: These are much less common and happen with a genetic disorder called cystinuria.
Struvite stones: This form can appear in people who have frequent urinary tract infections.
The most common types of stones are calcium or uric acid stones. You can reduce your risk of getting them by making some changes to your diet.
What foods can cause kidney stones?
Certain foods are more likely to cause kidney stones than others. Limiting these substances in foods is helpful for any type of stone but more so with calcium stones.
Sodium
Salt is made up of sodium and chloride. And the sodium component can play a big role in kidney health. To lessen your sodium intake, you need to reduce your salt intake. You can find high amounts of salt in:
Canned foods like beans or vegetables sold in cans
Processed foods like pizza, crackers, or macaroni and cheese
Cured foods like hams or pepperoni
Prepared foods like meals at a restaurant
Animal Protein
Protein helps keep your body working at its best. But it is best to stick to the daily recommended amount, which is 1 gram of protein per kilogram of body weight per day. As an example, a 200 pound person should eat about 90 grams of protein per day.
Your risk of stones may grow when you eat more than the recommended amount. This is especially true for animal protein, which includes:
Beef
Pork
Poultry
Eggs
Seafood and fish
Oxalate
High amounts of oxalate in your urine can raise your chances of getting a stone. While all fruits and vegetables contain oxalate, some have higher amounts, including:
Kale
Spinach
Collard greens
Rhubarb
Almonds
Rice bran and buckwheat
Potatoes
Beets
It’s still important to eat plenty of fruits and vegetables, as they can help your urine be less acidic. This can help lower your chances of getting a stone. Try to limit the ones that have very high concentrations of oxalate.
Calcium
You may think that avoiding calcium can help reduce your risk of calcium stones. But calcium rich foods are okay — and actually help your urine stay balanced. In fact, either too little or too much calcium can increase your risk of stones.
If you eat too much calcium, your body gets rid of the extra in your urine. Higher calcium in your urine makes it more likely for a calcium stone to form. If you get too little calcium in your diet, the body is unable to get rid of oxalate as well. This can increase your chances of an oxalate stone.
So try to keep your calcium intake around the recommended daily allowance of 1000 mg each day. You can get about a quarter of your daily calcium in different ways, including through a single:
Glass of milk (8 ounces)
Mozzarella cheese stick
Cup of yogurt (8 ounces)
Vitamin C
When levels of Vitamin C are higher in your body, your urine tends to have higher amounts of oxalate. This makes it easier for a kidney stone to form. Interestingly, several studies have shown that diets high in vitamin C make it more likely for stones to form in men but not women.
Soda
Sweetened carbonated beverages — like soda — are high in fructose. Fructose causes your body to get rid of more calcium, oxalate, and uric acid into your urine. And all three of these substances can lead to kidney stones.
What foods can help lower your risk of kidney stones?
More research is needed to know which foods help prevent kidney stones. But here are some reportedly helpful foods:
Vegetarian diet: One recent study showed a plant-based diet could lower your chances of a stone. This diet includes protein from low-fat dairy products like milk and cheese.
Foods high in potassium: Potassium helps to bind up substances that can form stones. Avocados, potatoes, beans, and lentils are among foods that are high in potassium.
Foods high in magnesium: Like potassium, magnesium helps to tie up substances that can form stones. Nuts, beans, and leafy green vegetables are all foods high in magnesium.
Vitamin B6: This vitamin might reduce oxalate in urine and lower risk of stone formation. Early data suggests that large doses of B6 in women lowered their chance of getting a kidney stone. But a study in 2019 did not find that B6 reduced kidney stones.
Coffee and tea: Some research shows that these fluids helped reduce chances of a kidney stone. Although more research is needed, they may help because the caffeine increases urine production.
Orange juice: Orange juice has a lot of potassium citrate. This increases the amount of citrate in your urine. The increased citrate makes it less likely for stones to form.
There are a few other foods that are reported to help. But take caution with these foods:
Lemonade: This drink is thought to increase urine concentrations of citrate. This is a substance that helps remove harmful minerals from your urine. But studies have not consistently shown this helps prevent kidney stones and thus is not recommended.
Fish oil: It is thought that fish oil reduces calcium by changing the way the kidney filters calcium. But in trials in which different dosages of fish oil were tested, it did not lower their risk of kidney stones. So even though fish oil may have other health benefits, it is not clear if this extends to kidney stone prevention.
Beer and wine: The alcohol raises the amount of urine your body makes. It is thought that this works similarly to caffeine. But given the other health risks of alcohol, it’s best not to incorporate it into your diet for kidney stone prevention.
What else can you do to prevent kidney stones?
These changes to your lifestyle can also lower your chances of getting a kidney stone:
Increase fluid intake. One of the best things you can do to prevent kidney stones is drink plenty of water.
Maintain a healthy weight. Maintaining a healthy weight can have many advantages. Besides the heart and blood pressure benefits, it can lessen your chances of getting a kidney stone. If your body mass index or BMI is over 30, your risk of kidney stone significantly rises.
The bottom line
While there isn’t a magic pill that ensures you won’t get a kidney stone, there are changes you can do to lower your risk. You can make many of these diet changes without eliminating your favorite foods. Watch your intake of certain ingredients — like salt and animal protein. And try to eat them in moderation. Most importantly, remember to pick up your fluid intake. Water is always a good choice. But other beverages that can also be helpful.
References
Curhan, G. C., et al. (1999). Intake of vitamins B6 and C and the risk of kidney stones in women. Journal of the American Society of Nephrology: JASN.
Ferraro, P. M., et al. (2013). Risk of kidney stones: Influence of dietary factors, dietary patterns, and vegetarian–vegan diets. Nutrients.
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