Studies Show Amount and Choice of Beverages Can Affect Risk for Kidney Stones

New York, NY (February 16, 1999)

Increasing your fluid intake may help prevent kidney stones, and now new studies show that what you drink is as important as how much you drink. According to one recent study, people who drank over 2.5 liters (about 2 1/2 quarts) of fluid daily had a 38 percent lower risk of developing a stone than people drinking less than 1.4 liters (about 1 1/2 quarts) daily.

The researchers also examined the relationship between 17 different beverages and the risk for symptomatic kidney stones. Surprisingly, the risk was lowered among coffee (regular or decaffeinated), tea and wine drinkers, while grapefruit juice seemed to increase the risk. In fact, each additional 3 ounces of grapefruit juice a day increased the risk by 44 percent. Beverages like coffee, tea and wine may reduce stone risk by increasing the flow of a more dilute urine, but the reasons for the higher risk with grapefruit juice are not clear. Other beverages like milk, soda and other juices did not seem to affect the risk of stones in this study.

In another recent study, cola drinks were implicated as a possible culprit in kidney stone formation. When a group of men who were heavy cola drinkers (at least 5 1/3 ounces a day) and had suffered a previous bout of kidney stones cut their consumption of colas to less than half their customary levels, they were almost one third less likely to experience a recurrence of stones.

Kidney stones affect millions of Americans each year. The main symptoms of kidney stones are:

  • severe pain,
  • nausea and vomiting,
  • frequent need to urinate,
  • burning urination,
  • blood in the urine, and
  • blocked flow of urine.

If infection is present, you may have fever and chills and cloudy or foul-smelling urine. If you have any of these symptoms, see your doctor. For more information about kidney stones and treatment, contact the National Kidney Foundation.