A kidney stone is exactly that: a hard mass of minerals and salts that forms in your kidneys. Certain foods and drinks have chemicals that can often cause these painful crystals to form.
There are several types of stones. Foods that aren’t good for one kind of stones may be OK to eat for another type. If you’ve had a kidney stone, ask your doctor about its type. That’ll help you know which foods to avoid.
But if you just want to be careful about all types of kidney stones, a good rule is to avoid eating too many salty foods and meats.
Calcium Kidney Stones
The most common type of kidney stone is a calcium stone.
Calcium oxalate stones
More people get this kind than any other. Calcium oxalate stones form when calcium in your urine combines with oxalate, a chemical naturally found in many foods.
If you’ve had one of these stones, watch out for:
Animal protein. Limit beef, pork, eggs, cheese, and fish, as they may raise your chances of most types of kidney stones.
High-oxalate foods. Many plants contain oxalate, so it’s hard to avoid it entirely. Plus, a low-oxalate diet isn’t good for most people. If you have this type of kidney stone and have high levels of oxalate in your urine, try to limit:
- Spinach and Swiss chard
- Raw prickly pear
- Sorrel
- Star fruit
- Beets
- Rhubarb
- Almonds
- Navy beans
- Baked potato with the skin
- Miso soup
- Grits
- Cocoa powder
- Bran cereals and shredded wheat cereals
- Supplements, such as cinnamon, green “superfood” supplements, and turmeric
Controlling your portion sizes can also help.
If you’re prone to calcium oxalate kidney stones, eating calcium-rich foods with oxalate-containing foods can help. Calcium can bind to oxalate in your digestive tract, reducing the amount of oxalate that reaches your urine. This can help your body handle oxalate without turning it into a kidney stone. So, pair your spinach salad with low-fat cheese. Or mix nuts or berries into yogurt.
Salt. If you eat a lot of sodium, an ingredient in salt, it raises the amount of calcium in your urine. This extra calcium can combine with oxalate and form crystals that may grow into kidney stones. So limit canned foods, packaged meats, fast foods, ultraprocessed foods, and too many condiments in your diet.
Vitamin C. Too much can make your body produce oxalate. So don’t take more than 500 milligrams a day.
Calcium phosphate stones
These form when calcium in the urine combines with the mineral phosphorus. If you’ve had one of these, you don’t need to worry about oxalate. But do watch for:
Animal protein-rich foods, including:
- Organ meats, like chicken or beef liver
- Milk, cheese, and other dairy products
- Eggs
- Seafood
Foods that can make urine more alkaline, including:
- Fresh fruit juices (except orange, cranberry, and nectarine)
- Vegetable juices
- Molasses
Processed foods. Phosphorus is a common additive and preservative. So, limit the following:
- Fast food
- Bottled soda
- Frozen foods
- Lunch meats
Read the label for ingredients starting with “phos.”
Sodium. Most Americans get too much already. Aim for no more than one teaspoon of table salt a day.
Uric Acid Stones
You get these if your pee is too acidic. These stones have uric acid, a substance your body makes as it breaks down chemicals in food. Unlike with calcium oxalate and calcium phosphate stones, sodium isn’t a special issue here.
Animal protein. Eating too much red meat, poultry, eggs, and shellfish does two things:
- It makes your body make more uric acid.
- It can rob your system of citrate, a substance that helps prevent kidney stones from forming and may slow their growth.
To get enough protein, you can swap your meat and poultry for:
- Beans, dried peas, lentils, and peanuts
- Tofu, soy curls, and soy milk
- Nuts, such as almonds, walnuts, and cashews
Sugary drinks. Tart drinks such as lemonade, limeade, and fruit juices are naturally high in citrate, which helps keep kidney stones at bay. But cut out foods and drinks flavored with sugar, especially high-fructose corn syrup. They can lead to stones.
Cystine Stones
These come from a rare condition that runs in families called cystinuria. This condition causes a natural substance called cystine to leak into your urine. Cystine stones tend to be larger than other types. If you’ve had one, you might have another.
Preventive Habits
Although kidney stones aren’t always avoidable, there are some habits you can prioritize to help prevent kidney stones.
When to Talk to a Doctor About Kidney Stones
Call your doctor if you have symptoms such as:
- Blood in your urine
- Trouble peeing
- Pain with a fever and chills
- Pain, throwing up, and stomach upset
If your pain is so severe that you can’t get comfortable, get it checked out.
Takeaways
A kidney stone is a solid mass of salts and minerals in your kidneys. Some foods and drinks have substances that can lead to these stones. There are a few types to be aware of. Depending on the case, they can be very painful.
If you want to be careful to avoid all types of kidney stones, a good rule of thumb is to avoid eating too much meat and salty foods.
FAQs About Diet and Kidney Stones
Here are some of the most commonly asked questions about diet and kidney stones.
Can I drink coffee or tea if I am prone to kidney stones?
Yes. Drinking coffee and tea in moderation is OK. Some research suggests that coffee and tea may help prevent kidney stones. Either way, staying hydrated is most important.
Should I stop taking calcium supplements if I have calcium-based stones?
Talk to your doctor about whether you should stop taking your calcium supplements. Research suggests that taking large amounts of calcium supplements may lead to calcium-based kidney stones. If you take these supplements, it’s a good idea to take them with a meal.
How much water do I actually need to drink per day to prevent stones?
Aim to drink no more than eight 8-ounce glasses of water per day.
Are plant-based or vegan diets safer for kidney stone prevention?
Yes. Research suggests a balanced vegetarian diet with some dairy is the most protective diet for kidney stone prevention. People looking to avoid kidney stones must avoid a diet high in animal protein and low in calcium, as it may increase the risk.
