Cranberries may help to prevent urinary tract infections (UTIs), but they won’t work as well as taking antibiotics, a new study shows.

If you get recurrent UTIs (more than three infections a year), your doctor may suggest you take continuous antibiotics to reduce the number of infections you get.

Many women are unhappy with taking antibiotics continually, either because of unwanted side effects such as yeast infections, or the risk of bacteria becoming resistant to the drugs. So some women prefer the idea of taking a natural remedy like cranberries instead of antibiotics.

There is some evidence that drinking cranberry juice or taking cranberry capsules may help reduce the chances of getting a UTI. But, until now, there hasn’t been research to show whether cranberries work as well as antibiotics.

In a good-quality study (a randomized controlled trial), 221 women who had frequent UTIs took either cranberry capsules or antibiotics every day for a year. At the end of the study, the average number of infections for women taking cranberry capsules was four, compared with two for women taking antibiotics.

However, there was a downside. All the women had regular urine tests, to examine the bacteria in their urinary tract. After just a month of taking daily antibiotics, 9 in 10 women showed signs of antibiotic-resistant bacteria in their urine. That compared with just under 3 in 10 women who took cranberry capsules.

Antibiotic resistance means bacteria have evolved so that they are no longer killed by certain antibiotics. That means that, if you did get an infection, the usual antibiotics might not work.

Bottom line: If you have repeated UTIs, antibiotics are more likely to reduce the number of infections you get than cranberry capsules. However, antibiotics do have a downside, and you may prefer to try cranberries to see if they work for you.

Sources
Cranberries vs antibiotics to prevent urinary tract infections [Archives of Internal Medicine]

—Anna Sayburn, BMJ Group

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