Kidney stones are a well-known disorder of the urinary tract, and they are comprised of a hard, stone-like material that forms on the kidney walls due to a buildup of minerals in urine. The majority of kidney stones are so tiny that they traverse the urinary system without causing pain. However, a large enough stone can cause urinary blockage. This is very painful, and requires some kind of treatment or surgery.
In the United States, about 1 million people get kidney stones annually. Stones usually affect people between the ages of 20 and 40, and men are affected more often than women. A family history of kidney stones also increases risk.
Some people have kidney stones made from calcium oxalate (OX-uh-layt). For these individuals, cutting back on high-oxalate foods and salt may help prevent the formation of kidney stones. Oxalate is found in many foods., and if you are trying to maintain a low oxalate diet, you should limit your intake to 40 to 50 mg each day. It’s also important to drink plenty of fluids – 8 to 13 cups each day. Your body may turn extra vitamin C into oxalate. Avoid high doses of vitamin C supplements (more than 2,000 mg of vitamin C per day)
The following charts may help you avoid high-oxalate foods. Food and drink serving sizes are 3.5 ounces (100 grams), unless otherwise noted.
Avoid these High-oxolate Foods and Drinks
High-oxolate foods have more than 10 mg of oxalate per serving
Dark or “robust” beer
Juice made from high oxalate fruits (see below for high oxalate fruits)
Fats, Nuts, Seeds
Cereal (bran or high fiber)
Crisp bread (rye or wheat)
Whole wheat bread
Whole wheat flour
Beans (baked, green, dried, kidney)
Peppers (chili and green)
Potatoes (baked, boiled, fried)
Black pepper (more than 1 tsp.)
Limit these Moderate-oxalate Foods and Drinks
You should have no more than two or three servings of these foods per day. Moderate-oxalate foods have 2 to10 mg of oxalate per serving
Guinness draft beer
Twining’s black currant tea
Fats, nuts, seeds
Purple and Damson plums
Ravioli (no sauce)
Spaghetti in red sauce
Cinnamon Pop tart
Potato chips (less than 3.5 oz.)
Enjoy these Low-oxalate Foods and Drinks
Eatas much of these low-oxalate foods as you like. Low-oxalate foods have less than 2 mg of oxalate per serving.
In this short video clip, Urologist Dr. Jared Berkowitz explains that individuals who are trying prevent kidney stones need to drink plenty of water – six to eight glasses a day, as well as avoiding foods high in oxalates, such as spinach, tea, chocolate and nuts.
Dr. Omar Benetiz, M.D., discusses simple ways you can prevent calcium oxalate kidney stones, hydration being one of the keys to combat this particular type of oxalate stone. The reduction of calcium itself isn’t necessarily the best idea according to the doctor, especially for women with osteoporosis that require calcium supplementation.