Does Cranberry Juice Help UTIs?

3. Taking cranberry in any form, liquid or tablet, reduced the symptoms of UTIs

Cranberry juice and cranberry compounds helped alleviate pain with urination, urinary leakage, an urgent need to pee, fever, achiness, foul-smelling urine and fatigue by more than five times. If you can’t stand the bitter taste of cranberry juice and don’t want the extra sugar (and calories) of sweetened juice, “cranberry supplements will give you those same benefits,” Moro says, recommending that people consume plenty of liquids as well.

Not a substitute for medical treatment

Does this research — which looked at individuals of any age and gender who were at risk for UTIs but excluded studies of catheterized patients — mean that cranberry juice is a treatment for UTIs? No, Moro says. “Cranberry juice can’t treat UTIs, and we’re not looking for that,” he says. “We’re looking to reduce patients’ reliance on antibiotics. There’s a real interest in pursuing, as quickly as we can, nondrug interventions or lifestyle changes that can help with prevention and treatment.”

“If you have a urinary tract infection, you need to be treated,” confirms Aaron Potretzke, M.D., associate professor of urology at the Mayo Clinic in Rochester, Minnesota. “But it’s important to treat people for as short a period of time as is safe and possible.” He says many mainstream antibiotics are becoming less effective, antibiotic resistance is more common and more organisms resistant to multiple drugs can be treated only with IV antibiotics. “It’s a pressing area of concern.”

If you have a UTI, Moro says, your doctor might give you a prescription for antibiotics and tell you to take them if the ailment gets worse. He doesn’t recommend cranberry juice as a first-line treatment. 

The condition has to be managed with a clinician, because UTIs can cause serious issues. If a UTI goes untreated, the bacteria can move into the kidneys and, though rare, can lead to complications such as urosepsis, an infection in the bloodstream that originates in the urinary system, or pyelonephritis, a kidney infection that can cause nausea, vomiting and high fevers and requires oral and/or IV antibiotics.

Why cranberries help

The study’s findings are good news for many of us: UTIs affect more than half of women (including a lot of older women) and 20 percent of men. The usual cause is Escherichia coli, better known as E. coli. Though E. coli live harmlessly in our intestines, the bacteria can wreak havoc on our urinary tracts. For E. coli to cause a UTI, the bacteria need to attach to the walls of the urinary bladder; that’s why drinking any kind of fluid helps because it washes out some of the bacteria before they grab on and start the slow, inexorable march up to the bladder.

What is the magic bullet in cranberry compounds that makes them effective? “It’s something called proanthocyanidins, or condensed tannins, which are in the skin of cranberries,” Moro says. “They interrupt the ability of bacteria to adhere to the wall of the urinary tract.” He says extra fluids flush out the bacteria, and the cranberry compounds disrupt the bacteria’s ability to grow and cause an infection.

How much cranberry juice should you drink?

In most of the studies that the Australian researchers looked at, participants drank 120 milliliters (1/2 cup) to 300 milliliters (a little more than one cup) of cranberry juice once or twice a day. The Bond University study is not the only recent major analysis to provide evidence of the efficacy of cranberry juice in fighting UTIs. A 2023 global analysis, also out of Australia and published in the Cochrane Database of Systematic Reviews, looked at 50 recent trials involving almost 9,000 participants and found that consuming cranberry products reduced the risk of repeat symptomatic UTIs by 26 percent in women, by 54 percent in children and by more than 53 percent in people who were susceptible to UTIs after medical procedures such as radiation for bladder or prostate cancer. The analysis noted that few of the participants experienced side effects from cranberry products, the most common being stomach pain. 

That study came on the heels of Canadian research that found that proanthocyanidins, the polyphenols found in abundance in cranberries, seem to inhibit the formation of a biofilm of bacteria in the urinary tract. They may also deter E. coli genes in the gut.

Even better news for UTI sufferers may be on the horizon: An oral spray vaccine called MV140 shows promise in fighting off recurrent UTIs for up to nine years. The vaccine, which is made up of four types of inactivated bacteria common to the infections, is administered by spraying under the tongue twice a day for three months. It is used in other countries but hasn’t been approved by the U.S. Food and Drug Administration.