Of the 54 women in the extra-water group who completed the 12-month study without any major deviations from the protocol, 93 percent experienced two or fewer confirmed UTIs. In contrast, 88 percent of the 59 final control participants had three or more UTIs during the study period.
Despite the inherent limitations of the trial, Dr Grady believes the results should be sufficient to encourage women with recurrent UTIs to drink more water, particularly since the quantity in question would have no ill effects other than making one need to pee quite often.
“We realize that this trial was not blinded, the primary outcome was self-reported, and it was sponsored by Danone Research, which sells the bottled water used in this study," she said. "However, the research question is important and the intervention was safe, easy, and effective (and it would be impossible to blind a trial in which drinking water is the intervention).”
But to reduce costs and wasteful plastic use, Grady recommends tap water over bottled.