Sometimes likened to the pain of childbirth, kidney stones afflict more than 600,000 Americans each year, according to UltimateCitrus.com. Various factors can contribute to the risk of kidney stones, including a family history of kidney stones, kidney disorders, urinary tract infections, metabolic disorders such as hyperparathyroidism, as well as inherited conditions, such as renal tubular acidosis, cystinuria and hyperoxaluria. People who have had intestinal bypass or ostomy surgery also have greater risk of kidney stones. If you are prone to stones, dietary factors can alter your risk. Certain types of fruit or fruit juice might decrease your risk of "giving birth" to a stone.
Dirty Jobs
Your kidneys, bean-shaped, fist-sized organs located on both sides of your body toward the middle of the back below the ribs, are tasked with the important but unglamorous job of creating urine by removing extra water, toxins and waste from your blood. These waste products are sent down muscular tubes, called ureters, which squeeze urine to the bladder. Kidneys also release hormones that regulate blood pressure, help produce blood cells and enhance the strength of your bones. Your kidneys regulate the amount of water in your blood and chemicals in your skin and body, including sodium, calcium, phosphorus and potassium.
Getting Stoned
Under various conditions, crystals in urine separate and form hard masses called kidney stones. Chemical that inhibit the formation of stones usually keep the stones small enough that you pass them without ever knowing you have them. When larger stones develop, they cause intense pain as they pass through the urinary tract. If stones are too large to pass, your physician may recommend procedures to remove the stones or break them into smaller pieces that can more easily pass. Complications can develop from kidney stones, including damage to the kidney, scarring, urinary tract infections or obstruction of the ureter.
Types
Different people are prone to develop different types of stones. The most common stones -- calcium stones -- develop when calcium in urine combines with phosphate, carbonate or oxalate from food you've eaten. Cystine, strucite and uric acid stones are associated with particular medical conditions such as cystinuria, urinary tract infection and gout.
Fruit Benefits
In general, fruit improves kidney health and reduces the risk of reoccurrence of kidney stones. People who follow the DASH diet -- short for Dietary Approaches to Stop Hypertension -- have a lower risk for recurrence of kidney stones, according to Tufts University Health Letter. The DASH diet emphasizes a high intake of fruits, vegetables and whole grains. High-fiber foods stabilize blood sugar, lower blood pressure, reduce the risk of diabetes and enhance kidney health.
Citrates
Fruits and vegetables increase production of the compound citrate, which inhibits the formation of calcium stones. Eat foods that enhance citrates to reduce your risk of developing calcium stones. Citrus fruits such as oranges, lemons, tangerines and limes contain high levels of citrates. Citrus juices, in particular, spike citrate levels and lower urine acidity, so they function much like the kidney-stone medication potassium citrate. Drink two to three glasses a day of lemonade, diluted lemon juice or orange juice to raise your urinary citrate level. Apple and cranberry juice reduce the recurrence of a rare form of kidney stone, brushite stones, but increase the risk for recurring calcium stones.
Fruit to Avoid
Although it is a citrus fruit, grapefruit juice might increase the risk of developing stones, according to DrHoffman.com. Certain fruit, such as berries, contain high enough levels of oxalates that their citrate levels don't compensate sufficiently to justify eating them given the availability of other fruit that is lower in oxalates. High oxalate fruits include concord grapes; figs; fruit cocktail; kiwis; lemon, lime and orange peel; rhubarb; canned strawberries; and tangerines. Berries that are high in oxalates include blackberries, blueberries, currants, dewberries, elderberries, gooseberries and raspberries.
References
- DrHoffman.com; Kidney Stones: Treatment and Prevention; Zina Kroner, D.O.
- National Kidney Foundation: Chronic Kidney Disease (CKD)
- National Kidney & Urologic Diseases Information Clearinghouse (NKUDIC): Kidney Stones in Adults
- "The New York Times"; The Claim: Fruit Juice Can Prevent Kidney Stones; Anahad O'Connor; March 1, 2010
- UltimateCitrus.com: Citrus Fruits, Liquids Can Prevent Stone Disease; Robert Irwin, Jr.
- University of Pittsburgh Medical Center: Low Oxalate Diet
