Dietary Management of Recurrent Kidney Stones

Introduction:

Following proper diet changes can prevent kidney stone recurrence. Certain interventions are suitable for all kidney stones, but some may require specific therapy to address the risk factor. Kidney stones are common and have a high recurrence rate. This article pinpoints the interventions to avoid the recurrence of kidney stones.

What Are Kidney Stones?

Kidney stones are solid masses formed from urine substances (minerals and salts). Calcium oxalate, uric acid, struvite, and cystine are the different types of kidney stones. Various waste materials are present in urine. Minerals, acids, and salts are in higher amounts than liquid and cluster together to form a solid mass. They continue growing until they are eliminated in urine. Certain chemicals in urine prevent the formation of kidney stones, or enough liquid removes them from the body. These stones are formed from calcium, phosphate, xanthine, urate, oxalate, and cystine. Once the stone is formed, it may stay in the kidney or travel down the ureter if it is smaller and washed out in the urine. In the case of bigger kidney stones, they may block the ureter and cause urine blockage, resulting in discomfort.

Calcium is found in almost 80 percent of kidney stones. The incidence of calcium oxalate stones is higher than calcium phosphate stones. Uric acid and struvite stones comprise between five percent and 15 percent of urinary stones. Xanthine, cystine, and protease inhibitors contribute to around one percent of kidney stones.

What Are the Symptoms of Kidney Stones?

Symptoms are more noticeable in larger kidney stones. This includes-

• Blood in the urine.

• Smelly urine.

• Cloudy urine.

• Nausea and vomiting.

• Fever.

• Pain in the lower back region.

• Difficulty in passing urine.

• Discomfort while passing urine.

What Are the Causes of Recurrent Kidney Stones?

Obesity, consuming food high in sugar and salt, little or no exercise, drinking less water, family history, and infections are the factors that lead to kidney stone formation. Consuming excessive fructose also causes kidney stones.

How Are Kidney Stones Diagnosed?

Kidney stones are diagnosed following a personal history, physical examination, and imaging tests. Tests include urine analysis, computed tomography (CT), X-rays, ultrasound, and blood tests. Imaging tests help determine the size and shape of the kidney stones.

How Are Kidney Stones Treated?

Managing kidney stones involves using medications and, if needed, surgery. Generally, smaller stones get passed through in urine. Larger stones, if they block the passage of urine, cause pain and infection, which requires surgery. The surgical procedures include shock-wave lithotripsy (sound waves break the stone, and broken pieces can easily move out of the body), ureteroscopy (a probe is inserted into the urethra, bladder, and then into the ureter to break and recover the stone), and percutaneous nephrolithotomy (a tiny incision is made and a tube is introduced into the kidney and a probe is used to break or remove the kidney stone).

What Is the Easiest Method to Prevent Recurrence?

Individuals must drink more fluids until they produce 2.5 liters of urine daily. This is the initial step to prevent recurrence. Most stones are formed due to a high concentration of minerals in a small fluid volume. Consuming beverages such as sodas and juices is acceptable, but ensure they have less salt and sugar content.

What Are the Dietary Changes That Help Prevent Recurrent Kidney Stones?

No specific diet can prevent the recurrence of kidney stones. It all varies depending on the individual and the type of stone. The diet for recurrent kidney stones includes the following:

Calcium Oxalate Stones:

• Hypercalciuria (excess calcium in the urine), hyperoxaluria (high oxalate in urine), hypocitraturia (less citrate in urine), hyperuricosuria (high uric acid in the urine), and decreased urine volume are the factors that increase the risk of calcium oxalate stones.

• Preventing these risk factors will help avoid calcium oxalate stones.

• Reducing the consumption of oxalate-rich foods (peanuts, rhubarb, and sweet potatoes) will prevent the formation of calcium oxalate stones in individuals who had it earlier.

• Consume calcium and oxalate-rich foods together. This will help them bind together in the intestines, which helps prevent kidney stone formation.

• A low-sodium diet is encouraged. A high-sodium diet increases calcium concentration in the urine, forming other stones.

• Increased intake of fruits and vegetables helps increase citrate excretion, which prevents the recurrence of calcium oxalate stones.

• Consume animal protein in less amount as it may favor the recurrence of stone.

Uric Acid Stones:

• Purines are naturally found in red meat, organ meat, and shellfish. Increased purine intake increases uric acid levels in urine, which causes highly acidic urine and leads to uric acid stones.

• Reduce the consumption of purine-rich food to reduce the recurrence of uric acid stones.

• Consume fruits and vegetables, low-fat dairy products, and whole grains, and follow a healthy diet pattern.

• Avoid drinking alcohol as it may increase the uric acid content in the blood.

• Consume less animal protein and more fruits and vegetables to reduce urine acidity, which helps prevent the recurrence of uric acid stones.

Cystine Stones:

• Increasing fluid intake is the only option to reduce cystine stone formation. Urine alkalinization increases the solubility of cystine, thus reducing stone formation.

• No specific dietary change can inhibit the formation of cystine stones.

Struvite Stones:

• A low-sodium diet can help prevent struvite stone formation.

• Surgical removal is the most appropriate treatment for struvite stones as they are larger.

What Are the General Diet Instructions for Reducing Kidney Stone Formation?

• Consume More Fluids: Individuals can consume any form of fluid, such as water, coffee, or low-sugar drinks. This will help reduce the concentration of urine and also increase urine volume.

• Reduce High-Oxalate-Containing Foods: Spinach, beets, rhubarb, wheat bran, and nuts are certain foods high in oxalate. These should be reduced in consumption.

• Consume Sufficient Dietary Calcium: Adding a good amount of calcium to the diet prevents kidney stones.

• Avoid High-Protein Intake: One can consume moderate amounts of protein.

• Avoid High-Sodium Intake: One must limit sodium intake as it may increase the calcium in the urine and favor the recurrence of kidney stones.

• Limit Vitamin C Supplements: High concentrations of vitamin C lead to increased oxalate formation in the urine.

Conclusion:

Kidney stones are more prevalent and have a high recurrence rate. Calcium oxalate stones are the most frequently formed kidney stones. Increased concentration of urine and low fluid volume contribute to the formation of kidney stones. Different dietary patterns must be followed for different types of kidney stones. Therefore, if individuals experience any symptoms relating to kidney stones, consult the nephrologist to determine the nature of the stone and follow the diet accordingly.