Everything you need to know about cranberry supplements


Cranberry has long been named in the Super Food Hall of Fame, and for good reason. It serves up a powerful punch of adored antioxidants, contains a fair dose of vitamins C, E and K, and, as a berry, is a healthy provider of dietary fiber (keep in mind that when we’re talking cranberries we mean that tart, hard fruit, and not its processed twins Cranberry Cocktail and dried cranberry).

For me, cranberries made a few annual appearances in my mom’s classic cranberry salad, but stayed low on my radar until a round of UTIs desperately drove me on a hunt for pure cranberry juice. I learned to drink it straight and later prescribed myself a periodic regimen of supplementation with cranberry pills. I was hooked. But since I’ve begun sharing my nutritional wisdom with strangers (my patients) who inquire about all sorts of nutrition myths, I’m less concerned about anecdotal success and more interested in what the science actually says.

Cranberries, usually as juice or pills, have a reputation for preventing and/or mitigating symptoms of UTIs. This makes sense for a few reasons. First, cranberries contain a substance that may inhibit bacteria from sticking to the walls of the bladder, limiting the chances of acquiring an infection. Second, consumption of cranberry may create an anti- inflammatory response that reduces symptoms and lowers the severity of a UTI episode.

How does this hold up in the real world? A 2012 review of 24 studies found a small trend of decreased UTIs in a population drinking cranberry juice compared to those taking a placebo, but the findings were not significant. Other reviews, however, did find significant reduction in new UTIs with either juice or pills, though many of these studies had small sample sizes, which limits their credibility. The most notable findings I tracked down were in a 24-week study published this year with a sample size of over 300 participants. The participants, who all had a history of recent and recurrent UTIs, drank 8 ounces of cranberry or placebo over the course of a day. Researchers found a significant reduction in new UTIs in the cranberry group.

What does this mean for us? I feel like this is yet another instance where research can support or discredit just about anything. Here the findings are not so much conflicting as they are just not overwhelmingly positive.

The thing to keep in mind, I think, is that even if cranberry supplementation is not a sure bet in UTI prevention, a daily dose of pills or juice does not seem lead to any undesirable side effects. If you’re a frequent UTI victim, it might be worth giving cranberry a try.