Waking up on a beautiful March day, you stretch, get out of bed, and start making your bed, when suddenly you feel a dull pain in your lower back. You simply shrug off the pain, associating it with the wrong sleeping position. The lower back pain becomes progressively sharper; eventually leading to an emergency room visit. This story is similar to my first experience with kidney stones. Nearly half a million Americans will end up in the emergency room this year due to the incapacitating pain associated with kidney stones. March is national kidney month and nutrition month, in bringing awareness to both topics, how are kidney stones and nutrition related?
What are Kidney Stones?
According to the National Institute of Diabetes and Digestive and Kidney Disease, kidney stones are hard, pebble-like, mineral deposits that form in one or both kidneys. Stones vary in size, shape, and composition. Some kidney stones are as small as a grain of sand, or as large as a pea. Kidney stones form when urine becomes highly concentrated allowing minerals to stick together forming the stones. Because of the variation in size and shape of stones, some kidney stones move through the urinary tract with little to no discomfort. Larger kidney stones can block urine flow in the kidneys, ureter, bladder, or urethra causing severe pain and may require surgery. Typically, kidney stones do not cause long-term damage. There are three main types of kidney stones: calcium oxalate, calcium phosphate, and uric acid stones. Calcium oxalate stones are the most common, making up about 60% of stones followed by calcium phosphate, and uric acid stones.
Who is At Risk?
- Family history: Risk doubles if a family member suffers from kidney stones
- Personal history: If you have had a kidney stone before, the likelihood of a recurrence is 50% or higher in five years and 80% in ten years
- Gender: About 12% of men and 7% of women will develop a kidney stone once in their lifetime
- Obesity: Research finds a high body mass index (BMI) or waist circumference increases kidney stone risk
- Dehydration: Not having enough water in the body or substantial sweating can cause kidney stones. Those who live in warmer climates are at increased risk for kidney stones due to increased fluid loss through the skin
- Undergoing gastric bypass surgery or intestinal surgery and additional medical conditions and medications—consult your physician to discuss your risk of kidney stones.
Prevention & Nutrition
Because kidney stones are composed of different minerals, talk to a physician about having stones tested to determine type of stone and further personalize dietary recommendations. Remember if you or a family member have suffered from kidney stones, there is a higher chance of repeat episodes; read suggestions for preventing kidney stones below:
- Drink plenty of fluids: Unless you suffer from kidney failure, 3 to 4 liters of fluid (12-16 cups) will secrete a sufficient 2.5-3 liters of urine throughout the day. The less concentrated the urine (more fluids present), the less likely the occurrence of stone formation. Including sugar-free lemonade, or 100% orange juice may also be beneficial in preventing stone formation due to the presence of citrate. If the recommended fluid intake feels overwhelming, start small. Monitor how much you drink on a normal day and try increasing intake in small increments, for example drinking 8 cups rather than your typical 6 cups of fluids and slowly increasing to 12 cups per day.
- Reduce Sodium: The more sodium consumed the higher the risk of kidney stones, among other serious health conditions. This is especially true among those individuals with calcium oxalate or calcium phosphate stones. A high sodium diet increases the amount of calcium in urine. Aim for the daily recommended 2,300 mg. of sodium per day with additional research supporting kidney stone former's going as low as 1,500 mg. of sodium per day. Read nutrition labels, looking at how many servings are in the package, and aim for 5% or less of the recommended daily value of sodium per serving.
- Watch the Oxalates: Oxalates are a compound found in seeds, nuts, legumes, fruits, vegetables, and grains. Nuts, peanuts, rhubarb, spinach, beets, sweet potatoes, chocolate, okra, sweet chard, tea, soy products, and wheat bran are specifically high in oxalates. This does not mean completely cut out these healthy foods if you suffer from the common calcium oxalate kidney stones, but cutting down on consumption of foods high in oxalates or try combining them with food high in calcium. Research finds consuming high calcium foods such as milk, cheese, and yogurt with high oxalate foods helps the oxalates and calcium bind in the stomach and intestines before reaching the kidneys, making the formation of stones less likely.
- Consuming Calcium does not cause Kidney Stones. Despite the name calcium phosphate or oxalate stones, calcium from food does not increase the risk of developing kidney stones. Studies have actually shown not consuming an adequate amount of calcium can increase the risk of developing kidney stones. Take caution when taking calcium supplements, as they have been show to increase the risk of stone formation.
- Limit Animal Protein. A diet high in red meat, seafood, eggs, and poultry increases the presence of uric acid and reduces the stone preventing citrate in the body. This is especially true for those who suffer from uric acid kidney stones. Try consuming more plant based protein.
- Embrace the DASH Diet: Studies have found those who embrace the Dietary Approaches to Stop Hypertension (DASH) diet have a reduced risk for kidney stones. The DASH diet, endorsed by the American Heart Association, is rich in fruits, vegetables, and low in animal protein and fat.
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