Dietary Features According to Kidney Stone Type

There are many reasons that encourage the formation of kidney stones. Stone disease is promoted by metabolic disorders due to overweight, diabetes, chronic inflammatory bowel diseases. Fluid intake and dietary features are also no less significant. Most often, stone disease begins with increased concentrations of calcium oxalate and uric acid and decreased citrate in urine.

Calcium oxalate stones tend to form in acidic urine, so a more alkaline diet is recommended. To prevent an increase in calcium levels in the urine, it is advised to consume less table salt and animal proteins and to limit the amount of oxalates. Oxalates are found in sweet fruits, nuts, legumes, wheat bran, tea, coffee, and most abundantly in rhubarb, spinach, beet leaves, broccoli, green beans, sweet potatoes, peanuts, soy, chocolate, dried and canned fruits. Ascorbic acid turns into oxalate, so large amounts of vitamin C should also be avoided. If you do eat products containing oxalate, simultaneously consume foods high in calcium. This way, calcium in the intestines is likely to bind with oxalate, and its amount in the urine will not increase significantly.

Urate stones. Those with these stones often suffer from gout. The formation of uric acid stones, like the crystals of gout in the joints, is promoted by purines in food. From them, uric acid is formed - a component of urate stones and gout crystals in the joints. Purines are most abundant in red meat, liver, kidneys, shellfish, fatty fish, so these products are recommended to be consumed rarely. For urate stones, a more suitable diet is plant-based - vegetables, grains, and also low-fat dairy products. It is very important that the urine is alkaline, as an acidic environment in the urine promotes the growth of urate stones. Uric acid stones are the only ones that can be dissolved by maintaining an alkaline urine pH of about 6.5-7. For the prevention of these stones, it is recommended to maintain a urine pH of about 6.2-6.8.

General tips suitable and important for all those suffering from stone disease

Drink enough water! Because with insufficient fluid intake, urine becomes more concentrated, creating favorable conditions for stone formation. Avoid sweet drinks with sugar or fructose, as excess sugar acidifies the urine, which is a favorable environment for the formation of many types of stones. Citrates alkalize urine, for example, natural lemon juices, potassium citrate, and potassium bicarbonate, which are found in food supplements. Additionally, by forming soluble compounds with calcium, citrates in urine reduce crystallization and stone formation.

Consume less table salt (sodium chloride). Excess sodium promotes greater calcium excretion with urine, thus increasing the calcium concentration in the urine, forming insoluble calcium compounds, and calcium becomes a component of stones. If a higher amount of calcium is found in the urine, it is recommended to reduce salt to 2 grams per day.

Consume less animal proteins. The optimal daily amount is no more than 1 mg/kg of body weight.

Animal proteins acidify the body, thus promoting greater calcium excretion with urine and stone formation. To reduce this risk, eat more plant-based foods that help maintain an alkaline environment.