Drinking cranberry juice for kidney stones can be either beneficial or harmful, depending on the type of kidney stone from which one suffers. Cranberry juice can help prevent stones in individuals suffering from struvite or brushite stones. Yet, cranberry juice may also encourage the growth of the most prevalent type of stone, the calcium stone.
Kidney stones are small, hard, mineral deposits generated in the kidneys that affect the urinary tract. Usually kidney stones are left to pass naturally through the urinary tract, though the process may be very painful. If the stone is large enough that it may cause blockages, surgery must be done to remove the stone. There are a number of different types of stones that may develop, all having different causes. Individuals who experience kidney stones are likely to have a recurrence, so it is good to have the stone tested to see what type it is so appropriate precautions can be taken against future stones.
Some believe that drinking cranberry juice for kidney stones is beneficial because the antioxidants in cranberry juice clean out the kidneys and will even work to dissolve existing stones. There is little scientific evidence that drinking cranberry juice will actively reduce the size of existing stones, yet cranberry juice does promote bladder and urinary tract health, which may be a factor in preventing kidney stones.
In some cases, drinking cranberry juice for kidney stones has been shown to be an effective preventative measure. Struvite stones are the result of an infection, most often a urinary tract infection. Cranberry juice has been proven to help the body resist and recover from urinary tract infections. This is because cranberry juice gives the urine an acidic Ph, which helps kill infection-causing bacteria. Therefore, cranberry juice indirectly protects the body from struvite kidney stones because it protects the body from urinary tract infections.
Drinking cranberry juice for kidney stones is also effective in the case of individuals suffering from brushite stones. Brushite stones are rare and are made of calcium phosphate. Drinking cranberry juice reduces the amount of calcium phosphate in the urine, lowering the risk of developing this type of kidney stone.
For individuals suffering from calcium stones, drinking cranberry juice can be a bad idea. Calcium stones are caused by high amounts of calcium and oxalate levels in the urine. Studies have shown that cranberry juice causes increased urinary levels of both these compounds, therefore increasing the chances of developing a kidney stone instead of lowering it.
Even if one suffers from calcium stones that may be aggravated by cranberry juice, the act of drinking large quantities of the juice may still be beneficial. One of the leading causes of kidney stones is dehydration. When minerals become concentrated in the urine, kidney stones are more likely to form. Drinking large quantities of any liquid, including cranberry juice, can be a major factor in the prevention of kidney stones.