Cranberry Supplements and UTIs

Q. Can cranberry supplements prevent urinary tract infections?

A: About 8 million people in the United States get a urinary tract infection (UTI) each year, and about half of all women will have a UTI at least once in her lifetime.

UTIs, which cause urinary urgency and pain, are typically treated with antibiotics. Some people turn to the cranberry in the form of either cranberry juice or cranberry-containing products to ward off UTIs.

Cranberries contain components called proanthocyanidins, which may work against the bacteria invading the urinary tract. But can this flavorful little berry in supplement form really prevent infection? The results of several studies that aimed to determine whether cranberry supplements are effective against UTIs have been mixed.

A recent study at Weill Cornell Medical College in New York involved incubating samples of seven different cranberry supplements with the bacteria most commonly responsible for causing UTIs to measure the cranberry activity in response to the bacteria. The researchers found that only one supplement had enough proanthocyanidins to potentially ward off UTIs.

The U.S. Food and Drug Administration doesn’t oversee the quality and dosage of dietary supplements, which can vary even among one product from batch to batch, which explains the discrepancies. Still, many women insist that taking supplements or drinking cranberry juice keeps UTIs at bay despite the mixed study results.

But avoid the cranberry products if you’ve had kidney stones or are taking blood-thinning drugs such as warfarin or aspirin.

You can also take other measures to prevent UTIs, including drinking plenty of fluids, emptying your bladder completely each time you void, wiping from front to back after a bowel movement, not using douches or feminine hygiene sprays, and urinating after sexual activity.

Our advice. If you have a tendency toward developing UTIs, cranberry supplements might work, but you may need to try a few different brands. If you decide to try cranberry supplements, get your doctor’s OK first.

Learn more about Urinary Tract Infections and Foods That Worsen Overactive Bladder.