According to the National Health and Nutrition Examination Survey (NHANES), kidney stones affect approximately 1 in 11 people in the U.S.
They are more common in men than women. These stone-like lumps can develop in one or both the kidneys and can cause a great deal of pain.
Kidney stones develop when different types of chemicals in urine, such as uric acid, phosphorous, calcium and oxalic acid, become highly concentrated.
Small stones tend to pass out of the body without causing much problem. Bigger stones cause severe pain, which comes and goes.
Other symptoms include frequent need to urinate, less urination at a time, painful urination, blood in the urine, smelly urine, nausea, vomiting, chills, fever and restlessness.
Factors that increase a person’s risk of developing these stones include a family history of kidney stones, dehydration, being overweight, digestive diseases, urinary tract infections and eating a diet high in protein, sodium and sugar.
People who have had kidney stones in the past also are at a higher risk of the problem recurring.
Diet is a key factor that is easily within your control. Eliminating certain foods from your diet can help prevent kidney stones and support the overall health of your kidneys.
Here are the top 10 foods that trigger kidney stones.
1. Oxalate-Rich Foods
Kidney stones form due to a buildup of calcium oxalate, so eating oxalate-rich foods in high amounts can increase your risk. The oxalate found in urine combines with calcium to form calcium-oxalate kidney stones.
People who are at a higher risk of developing kidney stones should eat oxalate-rich foods in moderation. This includes foods like spinach, rhubarb, okra, beetroot, kale, celery, soy milk, strawberries and Swiss chard.
Also, keep your vitamin C intake to appropriate levels. Extra vitamin C may turn into oxalate.
People who are at a higher risk of developing uric acid stones should avoid foods that are high in purines, such as sardines. A high intake of purine increases the amount of uric acid in the urine and can lead to uric acid stones.
According to the American Urological Association, high intake of purine from animal protein, particularly from fish, can lead to hyperuricemia and hyperuricosuria in healthy individuals without stones.
Furthermore, purine-rich foods may trigger calcium-oxalate stones, because they increase the amount of calcium excreted in urine.
Limit your intake of sardines to once or twice a week and keep a close eye on the portion size, too. Other purine-rich foods that you should eat in moderation are anchovies, organ meats, bacon, scallops, shrimp and baker’s yeast.
3. Red Meat
Eating too much red meat, which is high in protein, can increase your risk of developing kidney stones. It is high in uric acid, a common cause of kidney stones.
Plus, the kidneys help metabolize and excrete nitrogen by-products from protein digestion. So,eating a high-protein diet increases the metabolic load on the kidneys.
Avoid eating red meat on a daily basis. Instead, limit your intake to once or twice a week.
4. Carbonated Drinks
Regularly drinking carbonated beverages, such as soda (with or without artificial sweetener), energy drinks and certain bottled juices, also increases the risk of developing kidney stones as well as kidney disease.
A 2007 study published in Epidemiology noted that cola beverages contain phosphoric acid that causes urinary changes and promotes kidney stones. It also increases the risk of chronic kidney disease.
In addition, a 2013 study published in the Clinical Journal of the American Society of Nephrology noted that intake of sugar-sweetened soda and punch is associated with a higher risk of stone formation.
Instead of drinking carbonated beverages, stick to plain water, flavored water, lemon water or fresh orange juice.
5. Non-Fermented Soy
Soybeans and soy-based foods that are genetically modified are harmful to the body and can affect the health of your kidneys. They contain high levels of oxalates, which bind with calcium in the kidneys to form kidney stones.
A 2009 study published in the International Journal of Biological Sciences analyzed the effects of GMO foods on mammalian health and concluded that the effects were mostly concentrated in kidney and liver function.
Plus, unfermented soy products like soy milk and tofu contain high levels of anti-nutrients including oxalates.
When buying soybeans, opt for organically grown varieties. Also, choose fermented soy products like miso and tempeh.
6. Refined Carbohydrates
Refined carbohydrates (such as refined sugar, white rice, refined flour and so on) make the body produce high levels of insulin, which causes calcium from the bones to end up in the urinary tract.
This triggers the formation of calcium-oxalate kidney stones. In contrast, complex carbohydrates take much longer to digest and cause only a small, slow rise in blood glucose and insulin levels.
A 1986 study published in Food and Chemical Toxicology highlighted the effect of dietary refined sugars and sugar alcohols on renal calcium-oxalate deposition in ethylene glycol-treated rats.
If you are at risk of developing kidney stones, avoid anything made with white or all-purpose flour.