Women are commonly advised to drink extra water to prevent recurrent urinary tract infections, or U.T.I.s, but until now there has been little evidence that it works. Now a randomized trial has found that women who drink more water do indeed get fewer infections.
Researchers studied 140 women with recurrent U.T.I.s who habitually drank less than one and a half quarts of water a day, and averaged 3.3 episodes of cystitis the previous year.
The scientists randomly assigned them to either continue their usual water and other liquid consumption or to drink an additional one and half quarts daily. The study is in JAMA Internal Medicine.
The women in the control group averaged 3.2 urinary infections over one year, while those who drank extra water averaged 1.7. There were no serious adverse events.
“We don’t know what proportion of recurrent infections are in people who are low-volume drinkers,” said the lead author, Dr. Thomas M. Hooton, a professor of clinical medicine at the University of Miami. “But we can now say there are data that show that if you want to reduce your U.T.I. risk, drink more fluids.”
The study was funded by Danone Research, which sells the Evian water that was used in the study. But, Dr. Hooton said, “There’s no reason to think that plain old tap water wouldn’t be just as effective.”