The Kidney Stone Diet: Foods to Eat, Foods to Avoid
Passing a kidney stone is incredibly painful. Anyone who has experienced one or more will tell you it’s one of the most unpleasant experiences — avoid at all costs! According to current statistics, 1 in 10 people will develop kidney stones during their lifespan. Prevalence in the United States has increased from 3.8 percent in the 1970s to 8.8 percent in the late 2000s. Not everyone will pass the stone or stones, which means they will need to utilize other costly therapies, some of which are invasive.
But there are certain situations and lifestyle choices that can encourage kidney stone formation and others that can help to prevent them.
Kidney stones form from accumulated dissolved minerals and salts that form on the inner lining of the kidneys and crystallize. Most stones are made up of calcium oxalate, but other compounds can contribute to their formation (uric acid, struvite, and cysteine). These stones, even when tiny, can instigate excruciating pain as they pass through the ureters. They can also grow to the size of golf balls, in which case they can block the ureters, preventing you from passing urine, creating a very painful and serious health situation. Having kidney stones is one risk factor for developing chronic kidney disease.
The most common cause of kidney stones is dehydration. That’s because your urine will become acidic, and that situation encourages urine stones to form. Dark colored urine is often a sign of dehydration, especially after exertion. Other dietary situations that can raise the risk of getting kidney stones include: high oxalate intake from certain foods, a high protein diet, and consuming too much sodium.
There are also health conditions that predispose you to kidney stones including Crohn’s disease, urinary tract infections, hyperparathyroidism, medullary sponge kidney, and Dent’s disease. A stone can also form from salt, the waste products of protein and potassium. Most stones form in the kidneys, though they can also generate in other parts of the genitourinary system.
Symptoms of a kidney stone can include:
Severe pain on either side of your lower back or in your abdomen.
Nausea and vomiting.
Fever and chills.
Blood in the urine.
Cloudy, foul-smelling urine.
Treatment can include hydration through intravenous fluid infusion to help the patient to pass the stone, extracorporeal shock wave lithotripsy (ESWL) for larger stones, removal of stones with ureteroscope, and when necessary, surgery. Patients often require strong pain medications during the acute condition. If the condition is caused by overactive parathyroid glands, doctors may consider removal of the glands.
The Kidney Stone Diet will help you to identify the foods you should avoid, or consume minimally, and also highlight the foods and beverages you should emphasize.
Limit high-oxalate foods such as nuts (cashews, peanuts), seeds, beets, spinach, grapefruit and cranberry juice, chocolate, rhubarb, asparagus, most berries, celery and parsley, potatoes, and buckwheat. Teas can also contain oxalates.
Avoid “high-protein diets” that emphasize large and frequent portions of proteins like meat, eggs, and pork.
Limit acidic foods like red meat, pork, hard cheeses, plain cottage cheese, and fish.
Avoid adding salt to foods.
Avoid highly processed foods that are high in sodium.
Avoid or limit soda, which has sodium, and other beverages containing sodium.
Avoid consuming excessive alcohol and also caffeine (chocolate, coffee, teas, energy drinks), which can speed up metabolism and contribute to dehydration.
Drink water as your primary beverage and drink adequate amounts.
Eat a variety of fruits and vegetables (except those listed above), which also have high water content.
Consider following the DASH Diet, which not only helps to lower blood pressure, but may also help to limit kidney stone risk.
Consume two servings of calcium-rich foods daily.
Increase citric acid consumption. Add lemon or lime juice to water, use lemons and limes when cooking, and use small amounts of orange juice in salad dressings and when cooking.
If you like oxalate-rich foods, then consider including calcium-rich foods in your diet. The calcium can bind to the oxalate and reduce the risk of stone formation. These include dairy foods, calcium-fortified foods like healthy cereals, and whole grain enriched breads.
Plant-based proteins are preferable to meat-based proteins. Include peas, beans, lentils, fish, and tofu. It’s also important to maintain a healthy weight and to choose a balanced diet that’s not designated high protein, if you do need to lose weight.
Though some herbal supplements claim to prevent kidney stones, there isn’t enough research to support these claims.
Beyond these basic suggestions, it’s also important to know the composition of the kidney stone(s), as that can help to further determine dietary choices. Be prepared to ask your doctor:
What foods could cause the specific stones I am developing?
Are there specific mineral or vitamin supplements that I should take or avoid?
Are there specific beverages I should avoid?
If you experience recurrent calcium stones, your doctor may prescribe a thiazide diuretic or phosphate-containing preparation. If you get uric acid stones, your doctor may prescribe allopurinol to lower uric acid levels in your body. If struvite stones are a problem, your doctor may put you a course of low-dose antibiotics. If cysteine stones are a problem, your doctor will likely recommend intense hydration and possibly a medication to lower cysteine levels, if necessary.
Kidney stones can occur in children as young as 5. The recent increase of kidney stones in the pediatric population in the U.S. is attributed to several factors, including early introduction of a highly processed diet, sodas, and other sweetened beverages including sports drinks, which have also replaced water for many people.