Preventative Medicine for Kidney Stones

Kidney stones are small, hard deposits in the kidney formed by the crystallization of mineral and acids salts.  Approximately 80% of kidney stones are made of calcium oxalate.  As a result, the majority of research on kidneys stones is related to the prevention of calcium oxalate stones.  Other stones consist primarily of calcium phosphate, a mix of calcium oxalate and calcium phosphate, magnesium ammonium phosphate (struvite stones), and uric acid. 

Kidney stone formation thrives in an environment where the components of your urine are out of balance.  Although the formation of kidney stones is complex, it is frequently related to either a deficiency in the factors necessary for their prevention, such as glycosaminoglycans, magnesium, or citrate, or the result of supersaturation of the urine with calcium and/or oxalate.   Research has shown that hyperoxaluria (too much oxalate in your urine) appears to play a more crucial role in kidney stone formation than hypercalciuria (too much calcium in your urine).  When urine becomes too concentrated due to increased amounts of mineral and acid salts, dehydration resulting in decreased fluid available to dilute the urine, or lack of substances to inhibit their formation, the minerals crystallize and stick together, forming stones. 

Excessive amounts of oxalate in your urine may be caused by either your body creating too much of it, or by your intestines absorbing a greater amount of it.   It is important to note that hyperuricosuria (too much uric acid in urine) is not only a risk factor in the formation of uric acid stones, but is also responsible for the creation of calcium oxalate stones.  This link may be due to uric acid functioning as a medium for the crystallization of calcium oxalate stones.  Therefore, it is important to address uric acid levels, in addition to levels of calcium and oxalates in the prevention of calcium oxalate stones.

Risk Factors:
The following have all been reported as risk factors for the development of kidney stones: Being male (increased risk over being female), being an adult (especially over the age of 40), having a personal or family history, certain diets, obesity, dehydration, digestive diseases and surgery, hyperparathyroidism, certain urinary tract infections, renal tubular acidosis, and cystinuria.

Treatment Perspectives:
Conventional treatment for kidney stones may include the following: consumption of 2 L or more per day of water in order to dilute substances in the urine such as calcium and oxalate, some dietary adjustments, administration of potassium citrate to increase urinary excretion of citrate, other prescription medications, sound wave therapy, and surgery.

From a naturopathic medical perspective, your doctor may utilize interventions designed to decrease the amount of stone--forming substances in the urine, as well as provide you with  compounds that inhibit the formation of kidney stones, such as magnesium, citrate, and glycosaminoglycans, and help your kidneys to function better.  Such interventions include the use of dietary intervention, nutritional supplementation, botanical medicine and homeopathy. 

Dietary Intervention:

• Reduction of Oxalate-Rich Foods:  Although only a small amount of the oxalate found in urine comes from the diet (the rest occurs as the result of endogenous metabolism), people suffering from excessive oxalate excretion can benefit from reducing their intake of oxalate-rich foods.  These foods include chocolate, cocoa, coffee, tea, beans, spinach, parsley, chard, kale, celery, rhubarb, carrots, beet tops, peppers, cucumbers, sweet potatoes, strawberries, blackberries, raspberries, plums, currants, and oranges.  Furthermore, foods such as peanuts and almonds may contain small amounts of oxalates, but what they do contain has a high bioavailability.  As a result, consumption of these foods also increase urinary oxalate levels.
•  Reduction of Uric Acid Production in the Body: You can reduce the amount of uric acid in your urine by reducing the amount produced in your body.  Decreasing consumption of purine-containing foods, fructose, sucrose, and alcohol may reduce uric acid production.
•  Reduction of Refined Sugars: This is especially important with regards to those suffering from calcium oxalate stones, as consumption of glucose or sucrose has been found to increase levels of urine calcium.
•  Avoidance of Soft Drinks: Studies have shown a significant association between the consumption of sugared soft drinks and the prevalence of kidney stones. Therefore, it would be wise to avoid the consumption of sugared soft drinks if you are at risk for developing kidney stones. 
• Reduction of Salt: Studies have shown a positive relationship between high sodium intake and the formation of kidney stones.  
• Caution with Protein Consumption: Research has demonstrated that a higher than typically recommended intake of protein (such as with an Atkins diet, body builders, etc.) increases urinary calcium levels.  Therefore, caution should be taken when increasing protein intake above the normal recommended amounts.
•  Increased Consumption of Lemons/Lemon Juice: Since citrate is an inhibitory factor in the formation of kidney stones, increasing the amount of citrate in the diet has been shown to increase the amount of citrate in the urine, thereby helping to prevent the formation of kidney stones.
• Saturated Fat: People with ileal disease or a history of surgeries to certain areas of the digestive tract (such as jejunoileal bypass or ileal resection) have an increased risk for developing calcium oxalate kidney stones due to an increased absorption of dietary oxalate.  Reducing intake of saturated fat helps to decrease intestinal absorption of oxalate, which is a crucial component of preventative treatment for this population. 

Nutritional Supplementation:

• Magnesium: In vitro studies have shown that magnesium both inhibits the formation of calcium oxalate crystals as well as making it more soluble.  Furthermore, human studies have shown that magnesium supplementation decreases the amount of oxalates in the urine while increasing urinary levels of citrate (an inhibitor of stone formation). 
• Pyridoxine (B6): Supplementation with B6 has been demonstrated to reduce urinary oxalate levels. 
• Vitamin A: Results of studies have suggested that a moderate dose of vitamin A may be beneficial for certain patients for kidney stone prevention.

Prescription Supplementation:

• Potassium Citrate: Supplementation with potassium citrate has been shown to increase levels of citrate in the urine, which is beneficial because citrate is an inhibitor of stone formation.  This compound is available by prescription.

Supplements of Note:

• Calcium:  In the past, doctors have recommended a low-calcium diet for those stone formers with high levels of calcium in their urine.  The paradox here is that although reducing calcium in the diet does reduce levels of calcium in the urine, it also increases levels of oxalates in the urine. This is thought to be due to the fact that calcium inhibits the absorption of oxalate in the intestines.  As mentioned above, hyperoxaluria (excessive urinary oxalate excretion) appears to play a more crucial role in the formation of stones than hypercalciuria (excessive urinary calcium excretion).  This means that consumption of a low-calcium diet may actually raise your risk of forming stones, rather than decrease it as previously thought. Therefore, some experts advise eating a high-calcium (or at least normal-calcium) diet, rather than a low-calcium diet as many conventional doctors still suggest.  With regards to calcium supplementation, studies have shown that taking calcium supplements between meals may increase your risk of stones, while consumption of calcium supplements with meals demonstrates varying effects.  Therefore, it may be advisable to avoid taking calcium supplements unless you take magnesium at the same time.  Due to the fact that magnesium supplementation decreases stone formation, some experts suggest that taking magnesium with calcium may negate any harmful effects that calcium supplementation may cause. 
• Vitamin C: Contrary to popular belief, evidence shows that consumption of vitamin C does not actually cause kidney stones. The research illustrated in support of vitamin C causing stone formation was based on the conversion of vitamin C to oxalate ex vivo (in laboratory studies, after it is in the collection bottle and has left the body). Human studies have demonstrated that any increase in urine oxalate that vitamin C may cause is most likely counterbalanced by the many positive effects of the vitamin.  For example, research suggests that vitamin C may actually reduce the formation of calcium oxalate crystals and increase the solubility of calcium oxalate.  Furthermore, there have been no reports of kidney stone formation among patients of practitioners utilizing large doses of vitamin C (2-10 grams or more of Vitamin C/day) on a routine basis.  Therefore, please do not avoid taking vitamin C, as it has many beneficial qualities and has not been shown to cause kidney stones in humans.  
• Vitamin D: Caution must be advised when supplementing with vitamin D, as large doses may increase urinary levels of calcium, thereby increasing the risk of kidney stones. 

Other Natural Options:

• Herbal Medicine: There are a variety of herbs used both for prevention and treatment of kidney stones.  Some examples for prevention include Zea mays, Eupatorium pupureum, Hydrangea arborescens, Uritica dioica. For treatment: Ammi visnaga, Solidago canadensis, Dioscorea villosa, Valeriana officinalis, Aesculus hippocastanum, Lobelia inflata.  Note: Please be sure to see a qualified naturopathic physician or herbalist before attempting to utilize herbal medications, as improper use may be dangerous. 
• Homeopathy: There are numerous homeopathic remedies that may be suitable for the prevention and treatment of kidney stones, ranging from constitutional remedies to compounded formulas.  As homeopathy is very specific to each person, please see a qualified naturopathic physician or homeopathic doctor before beginning homeopathic treatment.  

As always, this list is merely suggestive of some of the treatment options available for the prevention of kidney stones.  Please see a qualified naturopathic physician for assessment and instructions on how best to utilize these recommendations.  

References:

Herbal Medicine; Sharol Marie Tilgner
Nutritional Medicine; Alan Gaby

The Mayo Clinic: www.mayoclinic.com