How Can I Prevent Kidney Stones?
Risk Factors for Kidney Stones
"Kidney stones" is a term that covers different types of small, solid crystals. They can have different causes and different food culprits. Some are related to kidney infections. Others form because you have too much of certain minerals in your system.
Genes can play a role, too. Forty percent of the people who get kidney stones have relatives who have them, too. Their bodies may get rid of too much calcium or too little citrate (a chemical found in citrus fruits) in their pee, for instance.
Other conditions that make kidney stones more likely include:
- Obesity. When you’re overweight, you tend to get them more often. The same is true if you have diabetes.
- Gout. This painful condition happens when uric acid builds up in your blood. That makes crystals form in your joints or kidneys.
- Intestinal surgery. If you’ve had certain types of gastric bypass surgery or other intestinal surgery, your risk may go up.
- Hyperthyroidism. It can raise calcium levels in your blood and trigger kidney stones.
- Certain kidney diseases. One example is polycystic kidney disease, in which clusters of cysts grow in your kidneys. Another is medullary sponge kidney, a birth defect that causes cysts to form in the organ’s tubes.
Middle-aged men are most likely to get kidney stones, though it can happen to people of any age or sex.
Causes of Kidney Stones
Even if you’re in good health, your diet may encourage kidney stones to grow. One top reason is you may not be drinking enough water. That means you’ll make too little pee, which gives the stones more chances to form.
Other things to watch:
- Colas. These beverages are high in fructose and phosphates, which may lead to kidney stones.
- Oxalates. These are organic compounds found in a number of foods, including healthy ones such as spinach and sweet potatoes. But oxalates also bind easily to certain minerals, including calcium, which then help form kidney stones.
- Salt (specifically, sodium). Lots of sodium, which you get mainly through salt, means more calcium in your pee. That ups your odds for kidney stones. Eating calcium-rich foods like kale and salmon is OK unless you also eat too much salt. Too little calcium in your diet may lead to kidney stones in certain people.
- Vitamin C supplements. Be careful with these. Research has found high doses of vitamin C taken regularly can double a man’s chances for a kidney stone. There’s no need to worry about vitamin C in food.
- Animal protein. Too many steaks, chicken, eggs, and seafood can build up calcium and uric acid in your body. That’s another cause of kidney stones.
- Medications. Some prescription and over-the-counter drugs can contribute to kidney stones, including antacids, certain antibiotics, decongestants, diuretics, steroids and certain medicines for cancer, HIV, and epilepsy.
- Previous kidney stones. If you’ve had them once, you’re likely to get them again, unless you take steps.
What You Can Do to Prevent Kidney Stones
If you’ve already had a kidney stone, your doctor may recommend medication to keep it from happening again. What kind will depend on what caused the stone.
Also, take charge of your diet:
- Drink lots of water. Stay hydrated, especially when you exercise.
- Check food labels. Read the ingredients. Avoid or cut back on foods with high amounts of ingredients like sodium chloride, monosodium glutamate (MSG), and sodium nitrate.
- Choose foods wisely. Usually it’s good to get more spinach and nuts in your diet. But if you have calcium oxalate stones, which are the most common type, your doctor may tell you to avoid or limit foods high in oxalates:
- Nuts, including almonds, cashews, pistachios, and peanuts
- Soy products, including soy burgers, soy milk, and soy cheese
- Oat and oat bran
- Red kidney beans, navy beans, and fava beans
- Beets, spinach, kale, and tomato
These foods are low in oxalates. Caution: Too much dairy food and animal protein can up your chances of less common types of kidney stones:
- Grapes, melons, bananas
- Cucumbers, cauliflower, cabbage, peas
- Cheese, milk, butter
- Beef, bacon, chicken, ham
- Eat citrus fruits. Lemons and limes are high in citrate, which helps prevent kidney stones.
- Get plenty of calcium. Not enough calcium in your diet can lead to kidney stones. It’s better if you get it from food, like low-fat dairy products, rather than supplements.