Ever heard that coffee can cause kidney stones because it dehydrates you? Not to worry. 

Scientists used genes that are linked to coffee consumption to estimate coffee intake in roughly 395,000 participants in the UK Biobank study and in 176,600 participants in the FinnGen study.

A 50 percent increase in estimated coffee consumption—say, from 1 to 1½ cups a day—was linked to a 40 percent lower risk of kidney stones.

What to do

Don’t hold back on coffee to avoid kidney stones. This type of study can’t prove that coffee curbs your risk of stones. But it minimizes the chances that something else about coffee drinkers explains their lower risk. And it fits with earlier studies that reported a lower risk of kidney stones in people who drink more coffee (regular or decaf).

When it comes to preventing kidney stones, the more liquids, the better. The exception: sugary drinks may boost your risk.