From the Guidelines
Foods that can increase the risk of renal stones include those high in oxalate, such as spinach, rhubarb, beets, chocolate, nuts, and tea, as well as foods rich in animal protein like red meat, poultry, eggs, and seafood. These foods can contribute to stone formation by increasing uric acid levels and reducing citrate, a stone inhibitor 1. High-sodium foods such as processed foods, canned soups, and fast food can also raise calcium levels in urine, promoting stone development. Additionally, foods and beverages with high purine content, including organ meats, certain seafood, and alcoholic beverages, particularly beer, can increase uric acid stone risk. Excessive consumption of sugar-sweetened beverages and foods with high fructose corn syrup may also promote stone formation.
Key Points to Consider
- Limit foods high in oxalate, animal protein, and sodium to reduce stone risk
- Increase water intake to at least 2-3 liters daily to help prevent stone formation
- Consume adequate calcium from dietary sources rather than supplements, as dietary calcium can help bind oxalate in the gut and reduce urinary excretion 1
- Incorporate citrus fruits which contain citrate that helps prevent stone formation
- Be aware that the timing of calcium intake is important, as taking calcium supplements between meals may diminish their ability to bind dietary oxalate 1
Mechanism of Stone Formation
The underlying mechanism involves these foods creating an environment in the kidneys where minerals crystallize more easily, either by increasing stone-forming substances or reducing natural stone inhibitors in the urine. According to the American College of Physicians guideline, efforts to prevent the recurrence of nephrolithiasis target decreasing concentrations of lithogenic factors and increasing the concentrations of inhibitors of stone formation 1.
Recommendations
To reduce stone risk, it is recommended to limit foods that can increase the risk of renal stones and follow a dietary approach that includes increasing water intake, reducing dietary oxalate, reducing dietary animal protein and other purines, and maintaining normal dietary calcium. This approach can help prevent the recurrence of nephrolithiasis and reduce the risk of stone formation.
From the FDA Drug Label
Throughout treatment, patients were instructed to stay on a sodium restricted diet (100 mEq/day) and to reduce oxalate intake (limited intake of nuts, dark roughage, chocolate and tea).
- Foods that can cause renal stones include:
- Nuts
- Dark roughage
- Chocolate
- Tea These foods can increase oxalate intake, which may contribute to the formation of renal stones 2.
From the Research
Foods that can cause renal stones
- Animal protein: High intake of animal protein can increase the risk of kidney stones, particularly calcium oxalate stones 3, 4
- Oxalate-rich foods: Foods high in oxalate, such as spinach, beets, and rhubarb, can increase the risk of calcium oxalate stones 3, 4
- Sodium-rich foods: High sodium intake can increase urinary calcium excretion, which can contribute to the formation of kidney stones 3, 4
- Foods low in citrate: A diet low in citrate, a natural inhibitor of kidney stone formation, can increase the risk of stones 5, 4
- Foods high in purines: Foods high in purines, such as meat, seafood, and poultry, can increase the risk of uric acid stones 3, 4
- Chocolate and cola: These foods may increase the risk of kidney stones due to their high oxalate content 4
Dietary recommendations to prevent renal stones
- Increase fluid intake to at least 2 liters per day 4
- Maintain a balanced diet with adequate calcium intake (800-1200 mg/day) 3, 4
- Restrict animal protein intake to reduce purine and methionine intake 3, 4
- Increase citrate intake through foods such as citrus fruits, melons, and vegetables 5, 4
- Restrict sodium intake to reduce urinary calcium excretion 3, 4
- Consider supplements such as potassium citrate or magnesium citrate to help prevent kidney stones 6, 7