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Preventing Kidney Stones
By Carol Sorgen

These tips will help renal dietitians counsel clients and patients about prevention.

The National Kidney Foundation estimates that one in 10 people will have a kidney stone at some point in their lives, with more than 500,000 people seeking treatment in the emergency department every year.

When there’s too much waste in too little urine, small crystals can form. These crystals can join together, forming a larger solid or stone. If the solid material grows too large, it prevents urine from being washed out and causes a painful backup in the kidney, ureter, bladder, or urethra.

According to the National Kidney and Urologic Diseases Information Clearinghouse, men are more likely to develop kidney stones, but the incidence rate among both men and women is increasing. In the late 1970s, less than 4% of the population had experienced kidney stones; by the early 1990s, more then 5% had experienced them.

Leslie Spry, MD, a spokesperson for the National Kidney Foundation and the director of the Lincoln Nephrology and Hypertension Dialysis Center in Nebraska, says diet often is a culprit of kidney stone formation. “Many of the popular diets today are high in protein and low in carbs,” Spry says, explaining that a high-protein diet changes the composition of the urine, making the formation of kidney stones more likely. “The higher the protein intake, the higher the risk you’ll develop stones.”

Other possible causes of kidney stones include drinking too little water, exercising too much or too little, being obese, undergoing weight-loss surgery, or eating foods with too much salt or sugar, including fructose, which can be found in table sugar and high fructose corn syrup.

However, Spry says most kidney stones are idiopathic in nature and “we just don’t know why.”

There’s no guarantee your clients or patients can avoid kidney stones completely, but they can lower their risk of this painful condition, which brings with it the possibility of serious—even fatal—complications. These recommendations can help:

• Drink enough fluids, primarily water, because they’ll help remove waste products from the urine, according to Spry. If clients are drinking enough fluids, their urine should appear light yellow to clear. If they exercise regularly or it’s hot outside, they should drink even more. Spry advises patients to drink enough water during the day so they have to get up at least once during the night to use the bathroom and then to drink a glass of water when they get up in the morning.

• Reduce excess salt intake, including obvious sources such as potato chips and French fries, but also more hidden sources such as lunch meats, canned soups, packaged meals, and even sports drinks.

• Attain or maintain a normal weight and eat a balanced diet that includes 50 g of protein as well as complex carbohydrates.

• Avoid “megadosing” on vitamins C and E because large doses are thought to contribute to kidney stone formation, says Nyree Dardarian, MS, RD, LDN, an adjunct faculty member at Drexel University’s College of Nursing and Health Professions in Philadelphia. If clients choose to take supplements, they shouldn’t exceed the Recommended Dietary Allowance for any vitamin or mineral.

For more information on kidney stones, visit the National Kidney Foundation.

— Carol Sorgen is a freelance writer living in Baltimore who writes about health, wellness, and travel.

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