We know kidney stones are painful, but what causes them?
There are actually several different types of kidney stones: calcium stones, struvite stones, uric acid stones, cysteine stones and other rarer stones. Calcium stones, the most common, are caused by an excess of calcium or oxalate, things commonly found in food and naturally in the liver.
Struvite stones are caused by an infection, like a urinary tract infection. Uric acid stones are caused by a lack of fluid or too much fluid, high-protein diets and gout while cysteine stones are caused by a hereditary condition that creates too much cystinuria, an amino acid.
What can you do to prevent these painful stones from forming? There are seven nutritional tips I give my patients:
1. Drink 8-12 cups of fluid a day. Half of your fluid should include a source of citric acid. Citric acid helps prevent formation of stones. An easy way to add citric acid to your daily fluids is include lemon juice in water or tea or switch to sugar-free lemonade.
2. Consume 3-4 dairy servings a day. Calcium from the dairy combines with oxalate from food, and the body will not absorb an excess calcium or oxalate. A good source of calcium is through milk or yogurt. Cheese, while full of calcium, is also full of sodium.
3. Lower sodium intake. A recommended amount is less than 3,000 mg per day. An excess of sodium produces too much calcium into urine. Lowering sodium can be achieved by avoiding high sodium foods and limiting added salt to food.
4. Consume two 3-ounce servings of meat, fish, seafood or poultry a day. Too much of these foods can increase calcium and uric acid.
5. Limit vitamin-C supplements. The number to stay under in vitamin-C consumption is 500 mg. Foods naturally rich in vitamin-C do not need to be limited, though.
6. Lower foods high in oxalate. Nuts, beets, tea, dark chocolate, cocoa, spinach, rhubarb, tofu and soy foods are high in oxalates. When consuming these foods, be sure to eat with a calcium rich food.
7. Maintaining a healthy body weight can reduce risk of recurring kidney stones.