Plenty of people who develop kidney stones are shocked when this common condition occurs. How do these extremely painful stones take hold—and what can be done to prevent them?
Before you tell yourself that kidney stones are something that you’d never suffer, consider this—one of every 10 people is destined to develop at least one of these excruciating stones in his/her life. Each year, more than one million people see their doctors because of kidney stones. Already had a kidney stone? You’re not off the hook—about half of kidney stone sufferers will develop another stone in five to seven years. How to stay in the stone-free zone…
The good news is that kidney stones can usually be prevented by making the right changes to your diet and lifestyle. The problem is that many of the prevention strategies are counterintuitive…and involve some surprising approaches, such as cutting back on foods that are widely considered to be healthful.
The majority of kidney stones are made of calcium and oxalate. During normal digestion, oxalate (found in many healthful foods, such as spinach and beets) combines with calcium (another generally healthful nutrient) and makes its way through the digestive system before being excreted.
If there is excess oxalate, however, it gets absorbed into the bloodstream and carried to the kidneys, where urine is produced. Most of the time, oxalate is removed in the urine, but if the urine becomes saturated with oxalate, stones can develop. Surprising ways to stop stones from forming…
STEP #1: Add just two daily servings of fruit and vegetables to your diet. When researchers at the University of Washington recently analyzed the diets of more than 80,000 postmenopausal women, they found that women who consumed the most fiber, fruits and vegetables had a 6% to 26% lower risk of developing kidney stones than women who ate the least. Good news: Just two additional servings a day were enough to make a big difference. Simple way to get two more fruit/veggie servings daily: Have an extra apple and a handful of carrot sticks.
STEP #2: Consume calcium. You might be wondering why foods that contain calcium—a main constituent of kidney stones—would help reduce your risk of developing the stones. Here’s why: Calcium gives the oxalate something to latch on to in the stomach. Otherwise, the oxalate ends up in the urine, where stones are more likely to form. Good sources of calcium: Yogurt, kale, bok choy and calcium-fortified foods. Exception: People who use calcium supplements may face a higher risk for kidney stones. If you use calcium supplements, take them with meals. That way, the calcium can bind with any oxalate that may be in the food.
STEP #3: Go easy on oxalates. Eating oxalate-rich foods in moderation usually doesn’t promote kidney stones. But if you start getting large amounts of these foods—for example, by regularly using lots of spinach or beets in homemade juices—you might have a problem.
If you have had kidney stones—or your doctor believes that you may be at increased risk for them due to such factors as a strong family history of the condition—talk to your doctor about limiting your intake of oxalate-rich foods such as spinach…Swiss chard…rhubarb…beets…all nuts (including almond milk)…chocolate (especially dark) …and soy/tofu products.
STEP #4: Eat less fish and other animal protein. Wait a minute—isn’t fish good for you? Fatty, omega-3-rich fish usually is healthful, but people at increased risk for kidney stones (including anyone with a history of stones) should limit their intake of fish and any type of meat to six ounces a day.
Here’s why: Protein is made up of amino acids and gets broken down into uric acid. Eating lots of animal protein acidifies the urine and can increase uric acid levels in the blood, leading to gout…or in the urine, leading to calcium-based or uric acid kidney stones.
STEP #5: Drink the right beverages. Staying well hydrated is crucial—drink enough water and other fluids so that your urine is clear or light yellow. But pay attention to what you drink. One very large study showed that drinking sugar-sweetened sodas and punches increased risk for kidney stones by a whopping 33%. However, orange juice, coffee (both decaf and caffeinated) and tea decreased risk by varying amounts…beer cut risk by 41%…and wine reduced risk by 33%. Even so, these fluids should be consumed in moderate amounts.
Make lemonade: About one-third of stone formers are low in citrate (your doctor can test your levels), which is a known stone inhibitor. Since lemons have more citrate than any other citrus fruit, low-citrate patients may benefit from drinking a mixture of one-half cup of fresh or bottled lemon juice and seven and one-half cups of water (sweetened to taste). Consume the entire batch throughout the day to keep a steady stream of citrate flowing through the kidneys.
STEP #6: Watch your salt intake. Sodium causes the kidneys to excrete more calcium into the urine, and many studies show that increased salt consumption raises the likelihood of kidney stones. Don’t get more than 2,000 mg of sodium per day.
STEP #7: Get moving! You might not think that exercise would affect your risk for kidney stones, but it does. A new study showed that even a small amount of physical activity reduced risk for kidney stones in women with no history of stones by 16%. Moderate activity (four hours of gardening or three hours of walking a week) reduced risk by 31%. There’s no added benefit to very strenuous exercise.
Physical activity, especially weight-bearing exercise, may increase calcium absorption into bones, which means less calcium is excreted in the urine.
