Many women have grown up believing that drinking cranberry juice can protect against pesky urinary tract infections (UTIs). But science has been slow to show that’s actually true.
Research published Monday (July 9) in the Archives of Internal Medicine takes another stab at it, analyzing the findings from 13 earlier studies, including one published in January 2011 that found cranberries did not prevent UTIs.
The studies together included a total of 1,616 subjects. Because the studies selected for inclusion in this meta-analysis were all conducted so differently from one another, it was hard to draw strong conclusions. In particular, some tested the effects of consuming cranberry juice (though the amounts used were not consistent), while others tested cranberry capsules.
The researchers found that the 2011 study’s findings were so out of sync with the others, concluding that drinking cranberry juice failed to protect college-age women against recurrent UTIs, that they considered it an “outlier.” When they removed that study from the pool, they found that, yes, cranberry consumption does appear to offer some protection against UTIs, particularly among women who have suffered repeat bouts.
Cranberry juice appeared to work better than cranberry capsules, the study found.
The study notes that up to 50 percent of adult women will experience a UTI at some point and that of those, as many as 30 percent will experience repeat infections.
Nobody’s sure why cranberries should be expected to prevent bacterial infections such as UTIs; it could be one of the hundreds of compounds the berries contain or some combination of compounds. The early, popular theory that cranberry juice acidified the urinary tract, making it inhospitable to bacteria, has been disproved, according to the study.
Still, if you’re subject to frequent UTIs, it seems sipping cranberry juice might be of some benefit. Just be sure to accommodate the calories in your daily total: An eight-ounce serving of cranberry juice cocktail delivers 120 calories (though reduced-calorie versions are available, too).
Do you get a lot of UTIs? Do you think cranberry juice helps ward off those infections?