10 Foods That Cause Kidney Stones
Kidney stones, or urolithiasis, occur when a solid piece of material forms in the kidneys (or urinary tract). When the stone is small (less than 0.5 cm), it may pass through the urinary system by itself with little to no symptoms. If the stone is more than 0.5 cm, the stone can cause blockage of the urinary system resulting in symptoms such as groin or loin pain, blood in the urine, and vomiting.
Approximately 50 percent of those with kidney stones may develop another stone within 10 years. Most stones develop due to multiple genetic and environmental factors. Examples include use of calcium supplements, obesity, high urine calcium levels, hyperparathyroidism, inadequate fluids, and gout. The diagnosis of kidney stones can be made based on symptoms, medical imaging, blood tests, and urine tests. Treatment includes pain control such as nonsteroidal anti-inflammatory drugs (NSAIDs) or opioids, tamsulosin, or procedures like percutaneous nephrolithotomy, extracorporeal shockwave lithotripsy, and ureteroscopy.
It is estimated that about 1 to 15 percent of the global population are affected by kidney stones at one point in their lives. In 2015, about 22.1 million cases occurred resulting in 16,100 deaths. Men are more commonly affected compared to women. Surgery to remove kidney stones has been documented as early as 600 BCE. For those at risk of kidney stones, there are also several foods that should be avoided. This article looks at 10 foods that can cause kidney stones.
Kidney Stones Causing Food #1: Organ Meats
Organ meats, or offal, refer to the entrails or internal organs of a butchered animal. It includes the kidneys, liver, heart, tongue, brain, and tripe. While some cultures may consider offal to be inedible, there are others who consider it a delicacy or use it in everyday dishes.
Some examples of offal dishes include sweetbread, pate, and foie gras. Organ meats can cause kidney stones as they increase uric acid levels. When the uric acid level is high, it builds up in the urine and settles to form a stone.
Kidney Stones Causing Food #2: Animal Protein
The consumption of animal protein such as red meat, eggs, poultry, and shellfish can increase the levels of uric acid in the body. It can rob the body of citrate, an important substance that helps prevent the formation of kidney stones. Like the consumption of organ meats, consuming animal proteins increases the uric acid levels, and concentration of uric acid in the urine can lead to the formation of kidney stones.
For those at risk of kidney stones, decrease consumption of animal protein and substitute it for plant-based proteins such as soy milk, beans, lentils, peas, tofu, peanuts, cashews, walnuts, and almonds.
Kidney Stones Causing Food #3: Alcohol
While alcohol has not been found to directly cause kidney stones, it can contribute to the increased formation of kidney stones. Alcohol such as beer that is grain based has an especially high content of purine. Purines are chemicals that can cause kidney stones.
While uric acid is usually excreted from the body through the urine, excessive purine can lead to uric acid accumulation, resulting in the formation of a kidney stone. Since obesity also contributes to the formation of kidney stones, the consumption of alcohol can lead to obesity, leading to kidney stones. Long-term alcohol use can also lead to kidney damage.
Kidney Stones Causing Food #4: Sugar
Sugar is sweet tasting substance derived from various sources such as sugarcane and sugar beet. Sugar is often added to food and beverages to make it taste sweet. Sugar consumption has increased over the years leading to health consequences such as obesity, tooth decay, and diabetes. Other possible consequences include dementia.
Studies have found that the consumption of added sugars has also been associated with a rise in urine calcium and a decrease in urine volume. This further concentrates the calcium in the urine leading to the formation of kidney stones. Upon further review, these studies also found that sugar depletes the bones of calcium.
Kidney Stones Causing Food #5: Chocolate
Chocolate is an edible substance made from roasted cacao seeds. It can be used in both foods and beverages. The earliest evidence of chocolate use dates back as far as 1900 BCE. The cacao seeds are bitter and must be fermented before the flavor develops.
Chocolate is a highly popular food and can be found in various desserts, cakes, candies, and cookies. Chocolate should be avoided among those at risk of kidney stones as it has a high content of oxalate and can contribute to the formation of kidney stones.
Kidney Stones Causing Food #6: Processed Foods
Processed foods or convenience foods refer to food that has been commercially prepared to ease the process of consumption. They are usually easily portable or have a long shelf life. Examples of processed foods include snack foods, shelf-stable foods, and TV dinners.
Processed foods have been linked to health issues such as obesity and high blood pressure. Processed foods may also cause kidney stones as they contain phosphorus, a common preservative and additive. Those at risk for kidney stones should limit their consumption of processed foods such as frozen foods, bottled colas, fast foods, and luncheon meats. Try to scan labels for ingredients that start with “phos” and avoid them.
Kidney Stones Causing Food #7: Rhubarb
Rhubarb is an herbaceous perennial that is edible. Although it is a vegetable, it is often used like a fruit. Rhubarb is often used in desserts such as pies. The plant contains high levels of oxalic acid. Individuals at risk of kidney stones should avoid eating rhubarb as it can cause kidney stones.
Oxalic acid is a colorless crystal that can be found in various plants. While there are many good foods that contain oxalic acid, the crystal can bind with other minerals such as calcium in the intestines to form kidney stones. The leaves and raw roots should be avoided at all costs as the concentration of oxalic acid is highest in these parts of the plant.
Kidney Stones Causing Food #8: Artificial Sweeteners
Artificial sweeteners or sugar substitutes are a food additive that leads to a sweet taste. Artificial sweeteners have zero calories and are derived through chemical synthesis or from plant extracts. It is important for the general public to be aware that artificial sweeteners are not always good for health.
Artificial sweeteners have been found to decrease the kidney functionality, resulting in the development of kidney stones. This can be attributed to the use of synthetic chemicals in the production of some artificial sweeteners. It is estimated that about two cans of diet drinks have been found to cause kidney function decline.
Kidney Stones Causing Food #9: Cured Food
Cured food is made through curing, a method used to preserve and flavor foods such as vegetables, meat, and fish. Curing is a process where salt is added to the food to draw out moisture through osmosis. Since curing decreases the water potential, the cured food decreases microbe growth, which contributes to food spoilage. Other curing methods may also involve smoking, cooking, or spicing.
Cured foods can cause the formation of kidney stones. This is attributed to their high salt content, which leads to the kidneys being unable to keep up and having to work harder to filter the salt from the body. High sodium, in turn, causes high calcium in the urine, resulting in the formation of kidney stones.
Kidney Stones Causing Food #10: Vitamin C
Vitamin C, or ascorbic acid, can be easily found as a dietary supplement. It is an essential vitamin for enzymatic production of some neurotransmitters, repair of tissue, and for the function of the immune system. While many people think that vitamin C supplements are beneficial, studies have failed to prove the claims that extra vitamin C is beneficial for various conditions such as cancer, cardiovascular health, and prevention of colds.
Vitamin C may also cause kidney stones as it may break down into oxalate, which contributes to the formation of kidney stones. Those at risk of kidney stones should discuss with their doctor before taking vitamin C supplements.
