Are you one of the many Americans who are fueled by caffeine? Coffee, tea, soft drinks and energy drinks are consumed to enhance mood, alertness and cognitive performance. While these are positive benefits, can caffeine also be causing kidney stones? Learn more about the research findings on kidney stones and the risks and benefits of consuming caffeine.*

What Are Kidney Stones?

Kidney stones are a common condition caused by chemical crystals (calcium oxalate, calcium phosphate, etc.) forming in the kidney. Certain factors like poor hydration, a high-salt diet, and obesity contribute to stone formation. Caffeine consumption has been suspected of contributing to stones, but research yields conflicting findings. 

What Are the Researched Benefits of Caffeine?

Multiple studies actually show positive effects of caffeine on preventing kidney stones. For instance:

• Three separate studies found that certain types of caffeinated beverages lower the risk of kidney stones. Caffeinated coffee, decaffeinated coffee, and tea are associated with an 8-31% lower risk of kidney stone incidence. Caffeinated and decaffeinated sodas, however, were not found to lower that risk. 
• Studies show a decrease in urinary oxalate excretion and an increase in urinary excretion of citrate in caffeine consumers. Both these factors help to inhibit the formation of kidney stones. 
• An in-vitro (performed in a test tube) study showed caffeine reduces the crystal adhesion of a kidney stone at the cellular level. This study strengthens caffeine’s role as an inhibitor, rather than a promoter, of a calcium oxalate kidney stone. 

Has Any Research Raised Concerns about Caffeine?

Caffeine is a diuretic, which can hasten dehydration, and some studies have suggested that caffeine may be related to a higher kidney stone risk due to its elevation of urinary calcium excretion. One 2004 study collected data from 39 kidney stone patients who consumed caffeine after a 14-hour fast. 

The data showed that caffeine slightly increased urinary excretion of the minerals calcium, citrate, magnesium, and sodium, but not oxalate. Coffee and many teas are high in oxalate, and doctors have long recommended limiting consumption in individuals at risk of developing calcium oxalate kidney stones. 

Should I Consume Caffeine?

Based on the available research, there have been more positive results than negative findings overall from caffeine consumption, particularly coffee and tea consumption, in preventing kidney stones. Keep in mind, however, that kidney stones can be a multi-factor condition for some people. Consult with your doctor concerning your risk factors and how much caffeine you should consume if you are at high risk. 

*Peerapen, P., & Thongboonkerd, V. (2018). Caffeine in Kidney Stone Disease: Risk or Benefit? Advances in Nutrition, 9(4), 419–424. https://doi.org/10.1093/advances/nmy016