Beets are one of the most oxalate-rich foods.

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Kidney stones can form when you have too much dissolved minerals and salts in your urine. [1] They can be tiny grains of stone that pass through your urine painlessly, but larger stones can get stuck, block the flow of urine, and be extremely painful. [2] About 50 percent of people who have had one kidney stone will develop another. [1]

You may have heard that changing your diet can prevent kidney stones. That is partly true, but it is more complicated than just avoiding certain foods. Some diet changes help prevent most kidney stones. Other changes depend on the type of stone you have. [1,3]

Types of Kidney Stones

Causes of kidney stones include your diet, but they also include lots of other causes like low urine volume, certain bowel conditions, being obese, several medical conditions, some medications, and your genes. [1] There are three more common types of kidney stones that may be linked to your diet. Calcium oxalate stones are the most common type, followed by calcium phosphate stones, and uric acid stones. [2,3]

Risk Factors for Kidney Stones

Kidney stones are common. About 11 percent of men and 6 percent of women will develop kidney stones. You may be at higher risk if you have already had a kidney stone or if you have a family history of kidney stones. Other common risk factors include:

• Not drinking enough fluids
• Having kidney disease or frequent urinary tract infections
• Having an inflammatory bowel disease
• Having a history of gout [2]

How to Prevent Kidney Stones

If you are at risk, or you have had a kidney stone, prevention is important. Kidney stones cause pain and blood in your urine. They can also lead to urinary tract infection and kidney damage over time. If you have had a kidney stone, it is important to find out the type, and work with your doctor on diet changes. The type of stone affects the changes. [1,3,4]

The most important thing everyone can do to prevent a kidney stone is drink enough water, at least 6 to 8 glasses per day. [3] If you have had a kidney stone, your doctor may ask you to drink about 10 glasses of water each day. [1]

Remember to increase the amount of water you drink on hot, sweaty days. People who do hot yoga, or sweat in a sauna, are at higher risk for a kidney stone. [4] Another all-purpose prevention tip is to eat five to nine servings of fruits and vegetables every day. The nutrients in fruits and vegetables are known to keep stones from forming. [1] If you have had a kidney stone and you know the type, there are specific diet changes for preventing another stone. [1,3,4]

Diet Changes Based on the Type of Kidney Stone

Foods to Prevent Calcium Oxalate Stones

Oxalate is a natural substance found in plant foods. It is very high in some foods. If you have this type of stone, your doctor may advise avoiding high-oxalate foods like spinach, rhubarb, and almonds. [1] Oxalate is found in many other healthy foods including peanuts, beets, and sweet potatoes. [3,4]

Because oxalate foods are healthy foods, current thinking is you don’t need to eliminate most of these foods from your diet if you include enough calcium along with oxalate foods. That’s because when calcium binds with oxalate in your digestive system, both oxalate and calcium are removed in your urine. They don’t form stones. Stones only form in urine when calcium and oxalate are out of balance. Make sure you get enough calcium by including dairy products like milk, cheese, and yogurt, as well as calcium-fortified juices, breads, and cereals. [1,3,4]

Other diet changes to reduce oxalate stones include limiting salt and animal proteins. For salt, it is a good idea to stick to the limit set by the Centers for Disease Control and Prevention of 2,300 milligrams per day. [1] Proteins called purines from red meat, chicken, pork, organ meats, eggs, fish, and shellfish can increase the risk for stone formation. Depending on your usual diet, your doctor may ask you to limit your protein foods. [1,3]

Foods to Prevent Calcium Phosphate Stones

Calcium phosphate stones may be prevented by reducing salt, limiting animal protein, and getting enough calcium from foods. [3]

Foods to Prevent Uric Acid Stones

Uric acid stones may be prevented by limiting animal protein, losing weight if you are overweight, and limiting both alcohol and sugar-sweetened drinks. [4]

The Bottom-Line on Diet and Kidney Stones

Other than drinking more fluids and eating more fruits and vegetables, a diet for kidney stone prevention is not a one-size-fits-all solution. If you have had a kidney stone, work with your doctor to control all your risk factors. Diet may be an important part of prevention. It will be important to balance your basic nutrition needs when limiting oxalate foods or proteins. In some cases, medications may be needed to help prevent a future kidney stone. [1]

RECOMMENDED FOR YOU

• Kidney Stones: Causes, Symptoms, Management and Prevention
• Preventing Kidney Stones
• Diet and Kidney Stones

SOURCES

1. American Urological Foundation, Preventing Kidney Stones, https://www.urologyhealth.org/educational-materials/kidney-stones-prevention
2. NIH, Definition & Facts for Kidney Stones, https://www.niddk.nih.gov/health-information/urologic-diseases/kidney-stones
3. NIH, Eating, Diet & Nutrition for Kidney Stones, https://www.niddk.nih.gov/health-information/urologic-diseases/kidney-stones/eating-diet-nutrition
4. National Kidney Foundation, 6 easy Ways to Prevent Kidney Stones, https://www.kidney.org/atoz/content/kidneystones_prevent