Caffeine may help prevent kidney stones. Researchers tracked nearly 218,000 nurses and other health professionals for roughly eight years. Those who typically consumed around 350 milligrams of caffeine had a 20 to 205 percent lower risk of kidney stones than those who consumed no caffeine. ( A 16 oz. Grande coffee at Starbucks has 330 mg.)
The researchers couldn’t be sure if it was coffee, rather than the caffeine, that explained the lower risk. When they looked at people who drank less than one cup of caffeinated coffee per day, caffeine was linked to a lower risk of kidney stones in men but not women.
Although the research looks promising, for now, drink plenty of fluids to lower your risk of kidney stones. It’s too early to know if caffeine or coffee lowers the risk further.