From the Guidelines
To prevent kidney stone attacks, drink plenty of water—at least 2 liters daily—to keep urine diluted and flush out stone-forming minerals, as recommended by the American College of Physicians 1. This approach is supported by multiple studies, including a clinical practice guideline from the American College of Physicians, which suggests that increased fluid intake is associated with a reduction in stone recurrence 1. Additionally, limiting sodium intake to less than 2,300 mg per day, reducing animal protein consumption to 6 ounces daily, and maintaining moderate calcium intake (1,000-1,200 mg daily) from food sources can also help prevent kidney stone formation 1. Some key points to consider include:
- Increasing fluid intake to produce at least 2 liters of urine per day
- Reducing dietary oxalate, animal protein, and sodium
- Maintaining normal dietary calcium
- Considering pharmacologic monotherapy with a thiazide diuretic, citrate, or allopurinol for patients with active disease in which increased fluid intake fails to reduce stone formation 1
- Avoiding sugar-sweetened beverages and maintaining a healthy weight
- Increasing fluid intake during hot weather or intense exercise to compensate for additional water loss. These measures work by altering urine composition to make it less favorable for crystal formation and aggregation into stones.
From the Research
Prevention Strategies
To prevent kidney stone attacks, several strategies can be employed, including:
- Increasing fluid intake to 2.5-3.0 L/d and ensuring diuresis of >2.0-2.5 L/d 2
- Maintaining a normal body mass index and avoiding cigarette smoking 2
- Dietary management, such as:
- Consuming sufficient calcium (1000-1200 mg/d) 2, 3, 4
- Limiting sodium intake (2 or 3-5 g/d of sodium chloride) 2, 3, 5
- Limiting oxalate-rich foods 2, 3
- Avoiding vitamin C and vitamin D supplements 2
- Limiting animal proteins to 0.8-1.0 g/kg body weight/d and increasing plant proteins in patients with calcium and uric acid stone and those with hyperuricosuria 2, 3
- Increasing the proportion of citrus fruits 2
- Using natural bioactive products, such as caffeine, epigallocatechin gallate, and diosmin 2
- Using medications, such as thiazides, alkaline citrate, other alkalinizing agents, and allopurinol 2, 5, 6
- Bacterial eradication and probiotics 2
Specific Prevention Strategies for Uric Acid Stones
For uric acid stones, specific prevention strategies include:
- Urine alkalinization to pH values between 6.2 and 6.8 using potassium citrate or sodium bicarbonate 6
- Reducing urinary uric acid excretion through a low-purine diet 6
- Using allopurinol to reduce the frequency of stone formation in hyperuricosuric patients with recurrent uric acid stones and/or gout 6
Importance of Dietary Factors
Dietary factors play a crucial role in the formation of kidney stones, particularly calcium oxalate stones 3, 4. Modifiable dietary factors can help reduce the likelihood of developing a kidney stone, and dietary counseling is an effective element of a therapeutic regimen and kidney stone prevention program 4.