Q: I’ve heard that drinking cranberry juice can help prevent a urinary tract infection (UTI). What about red wine?—Helen, Eau Claire, Wis.
A: It’s a common bit of folk wisdom that drinking cranberry juice can help prevent a urinary tract infection (UTI). UTIs result from the growth of bacteria in the kidneys, ureters, bladder or urethra, and while they’re more common in women, anyone can get them.
First things first: Does cranberry juice actually prevent UTIs? Some laboratory studies have indicated that cranberry compounds could reduce risk of infection by preventing bacteria from adhering to the bladder wall. These studies have largely focused on a particular class of polyphenol called A-type proanthocyanidins (red wine contains many proanthocyanidins and other flavonoids, but not this type). Large clinical studies, however, have not clearly linked cranberries with a reduction in UTIs. Nonetheless, Dr. Edward Forsyth, a urologist with Keck Medicine of the University of Southern California, told Wine Spectator that he recommends cranberry supplements (not juice, which is high in sugar) to his patients with recurrent UTIs. He reasons that “there is a possible benefit, and the risk from the over-the-counter supplement is very low.”
What does this mean for red wine and urinary health? “As a urologist and wine lover, I would hope [red wine would be beneficial], but I cannot say that the evidence supports this [claim],” says Dr. Forsyth. He points to a 2008 study that linked red wine polyphenols with reduced inflammatory response to bacterial infection. “This reduction in inflammation may make the symptoms feel better, but ultimately could slow the body’s ability to fight the infection,” thereby prolonging symptoms. He also points out that alcohol is a diuretic (it signals the kidneys to produce more urine), which “could make the pain of urinating during a UTI worse or more frequent.” And while many studies have examined the health effects of wine polyphenols, there’s not much research into how polyphenols might impact the urinary system.
Ultimately, says Dr. Forsyth, “there is no data to support the use of red wine for general kidney [and] urinary health.” As always, talk to your healthcare provider about incorporating wine into a healthy lifestyle.—Kenny Martin