Urinary infection? Try cranberries

Marcia had symptoms of a urinary tract infection, and it wasn’t the first time either. The 28-year-old teacher had seen me periodically over the past few years for the painful condition. Just like previous episodes, she felt burning with urination and had to keep running to the bathroom – usually without a minute to spare.

“I can’t work. I can’t function.” she said. “It’s driving me crazy.”

For quick relief, I prescribed antibiotics plus a medicine to make her bladder feel better. Then on her next visit, when Marcia was back to her usual self, we discussed her options for preventing UTI recurrences.

Marcia was adamantly opposed to taking preventive antibiotics.

“First, I’d like to give something more natural a try,” she said.

So she chose the stuff that old wives’ tales are made of – cranberry juice.

You may have known people who swear by cranberry juice for UTIs. But does it really work?

Overall, the bulk of research to date shows that cranberries hold promise for preventing urinary infections. One study of 150 young Finnish women compared the use of cranberry-lingonberry juice concentrate, a drink containing lactobacillus (the active ingredient in yogurt), or no therapy for six months.

Participants averaged 30 years old and had previously experienced an average of six UTIs. About 85 percent of the women had also taken an antibiotic for a UTI in the past year. Results showed a 20 percent reduction in the risk of infection among women receiving cranberry juice compared to no effect in the other groups.

Another study involving 150 women over a 12-month period showed similar results. Significantly more women taking cranberry juice or cranberry extract tablets remained free of UTIs during the year.

Researchers concluded that regular consumption of cranberry juice products could have a substantial impact on the more than 11 million women treated for UTIs every year in the United States.

What, exactly, do cranberries contain that helps ward off urinary infections?

In days of old, American Indians gathered and dried the fruit as a medicinal remedy for bladder and kidney ailments. Scientists have since discovered that the active ingredient in cranberries is a natural plant substance called proanthocyandin. The compound decreases the number of UTIs in a unique way. Here’s how that works:

Bacteria that commonly cause UTIs have hairlike protrusions that allow the organisms to stick to the inner walls of the urinary tract. Studies indicate that proanthocyandin in cranberries directly interferes with bacterial adherence. The substance thwarts the bacteria’s ability to gain a foothold, preventing the bacteria from colonizing and mounting a full-fledged infection. Your body can then flush out the invaders before they cause harm.

This method of boosting your bodily defenses makes cranberry juice well-suited for prevention. But unlike powerful antiobiotics, which kill bacteria outright, scientists say the fruit isn’t reliable for UTI treatment.

If you’ve had urinary infections, consult with your doctor about the best prevention methods for you. People with certain types of kidney stones, for instance, need to choose something other than cranberries.

When cranberry products are an option, researchers generally recommend one to three glasses of unsweetened juice per day. For pills, look for the words “spray-dried juice” or “juice concentrate” on the label.

Dietary supplements are not regulated for purity, safety or effectiveness, so carefully research any of these products before you buy.

Contact Dr. Elizabeth Smoots, a board-certified family physician and fellow of the American Academy of Family Physicians, at doctor@practicalprevention. com. Her columns are not intended as a substitute for medical advice or treatment. Before adhering to any recommendations in this column consult your health care provider.

2006 Elizabeth S. Smoots.