Bladder infections are a common problem for women, accounting for more than 6 million office visits each year. Men, because of the greater distance between their bladder and urethral opening, only rarely develop bladder infections.

The primary symptoms of a bladder infection are burning during urination, frequency of urination, and urgency to urinate, possibly accompanied by pain in the lower abdomen and cloudy or bloody urine. Occasionally, the infection spreads upward into the kidneys, producing symptoms such as intense back pain, high fever, chills, nausea, and diarrhea.

Conventional treatment for bladder infections consists of appropriate antibiotic treatment guided by urine culture. Women with frequent bladder infections may keep on hand a prescription for antibiotics to be used when symptoms arise. Some women may choose to take antibiotics continuously to prevent infection. Certain hygiene habits, such as showering before or urinating after oral sex or intercourse, are commonly said to be helpful, although this has not been proven.

Women who do not want to use antibiotics may be able to find some help through the use of herbs. However, if symptoms do not improve or signs of a kidney infection develop, medical attention is essential to prevent serious complications.

Cranberry
Prevention

Cranberry juice is commonly used to prevent bladder infections as well as to overcome low-level chronic infections. The cranberry plant is a close relative of the common blueberry. Native Americans used it both as food and as a treatment for bladder and kidney diseases. The Pilgrims learned about cranberry from local tribes and quickly adopted it for their own use. Subsequent physicians used it for bladder infections, for "bladder gravel," and to remove "blood toxins."

In the 1920s, researchers observed that drinking cranberry juice makes the urine more acidic. Because common urine infection bacteria, such as E. coli, dislike acidic surroundings, physicians concluded that they had discovered a scientific explanation for the traditional uses of cranberry. This discovery led to widespread medical use of cranberry juice for bladder infections. Cranberry fell out of favor after World War II, only to return in the 1960s as a self-treatment for bladder infections.

More recent research has revised the conclusions reached by scientists in the 1920s. It appears that cranberry's acidification of the urine is not likely to play an important role in the treatment of bladder infections; current research has instead focused on cranberry's apparent ability to interfere with the bacteria establishing a foothold on the bladder wall.1-7,30If the bacteria can't hold on, they will be washed out with the stream of urine. Studies suggest that in women who frequently develop bladder infections, bacteria have an especially easy time holding on to the bladder wall.8 Thus, when taken regularly, cranberry juice might fix this problem and break the cycle of repeated infection.

The best evidence for the use of cranberry juice for preventing bladder infections comes from a 1-year, double-blind, placebo-controlledstudy of 150 sexually active women that compared placebo against both cranberry juice (8 ounces 3 times daily) and cranberry tablets.9 The results showed that both forms of cranberry significantly reduced the number of episodes of bladder infections.

A double-blind study of 376 hospitalized seniors attempted to determine whether a low dose of cranberry juice cocktail would help prevent acute infections.31 It failed to find benefit, most likely due to the minimal dosage of cranberry: only 10 ounces daily of cranberry juice cocktail. Furthermore, because of the low rate of infections, it would necessarily have been more difficult for this study to producestatistically significant results.

In addition, a year-long open trialof 150 women found that regular use of a cranberry juice/lingonberry combination reduced the rate of urinary tract infection as compared to a probiotic drink or no treatment.12 However, because this study was not double-blind, the results are unreliable. (For more information on why double-blind studies are so important, see Why Does This Database Rely on Double-blind Studies?)

A review of 10 studies investigated the benefits of cranberry juice or tablets compared to a placebo control in patients susceptible to urinary tract infections. Among 1,049 participants, the researchers found the cranberry products reduced the incidence of urinary tract infections by 35%, a statistically significant amount, over a 12-month period. The effect was most notable in those with recurrent infections. However, many subjects dropped out of the studies early, suggesting that continuous consumption of cranberries is not well tolerated.38

In another review, researchers analyzed 13 randomized trials involving 1,616 people prone to urinary tract infections (eg, elderly people, people with bladder problems, pregnant women).41In 9 out of the 13 trials, the subjects who consumed cranberry-containing products experienced a decrease in the incidents of urinary tract infections. Another review of 16 randomized or quasi-randomized trials with 3,109 people prone to urinary tract infection showed cranberry juice, tablets, or capsules did not significantly reduce the risk of symptomatic urinary tract infection compared to control (placebo, water, or no treatment), antibiotics, or methenamine hippurate.43

On the negative side, three double-blind, placebo-controlled studies failed to find cranberry extract helpful for preventing bladder infection in people with bladder paralysis (neurogenic bladder).11,32-33However, a subsequent study of 47 patients with neurogenic bladder from spinal cord injuries found that the use of cranberry extract tablets over 6 months significantly reduced the risk of urinary tract infection.39

Treatment

A double-blind study evaluated cranberry juice cocktail for treatment of chronic bladder infections.10 This trial followed 153 women with an average age of 78.5 years for a period of 6 months. Many women of this age group have what are called chronic asymptomatic bladder infections: signs of bacteria in the urine without any symptoms. Half of the participants were given 10 ounces per day of a standard commercial cranberry cocktail drink, the other a placebo drink prepared to look and taste the same. Both treatments contained the same amount of vitamin C to eliminate the possible effect of that supplement. Despite the weak preparation of cranberry used, the results showed that the treatment significantly reduced bacteria and white blood cells in the urine.

Uva Ursi

Uva ursi has a long history of use for urinary conditions in both America and Europe. Until the development of sulfa antibiotics, its principal active component, arbutin, was frequently prescribed by physicians as a treatment for bladder and kidney infections. It appears that the arbutin contained in uva ursi leaves is broken down in the intestine to another chemical, hydroquinone. This is altered a bit by the liver and then sent to the kidneys for excretion.13 Hydroquinone then acts as an antiseptic in the bladder. (It is, however, potentially quite toxic.)

The European Scientific Cooperative on Phytotherapy (ESCOP) is a scientific organization assigned the task of harmonizing herb policy among European countries. ESCOP recommends uva ursi for "uncomplicated infections of the urinary tract such as cystitis when antibiotic treatment is not considered essential."14

Despite this recommendation, surprisingly little research has been done on uva ursi.15

Two studies evaluated the antibacterial power of the urine of people who were taking uva ursi and found activity against most major bacteria that infect the urinary tract.16,17 While this is interesting, what is really needed is a double-blind trial to discover whether use of uva ursi actually helps people with urinary tract infections, and none have been done.

One study did evaluate uva ursi for prevention of bladder infections. This double-blind trial followed 57 women for 1 year.18 Half were given a standardized dose of uva ursi (in combination with dandelion leaf, intended to promote urine flow), while the others received placebo. Over the course of the study, none of the women on uva ursi developed a bladder infection, whereas five of the untreated women did. However, this study is a bit of an aberration, because most experts do not believe that continuous treatment with uva ursi is a good idea.

As noted above, hydroquinone is toxic, and for this reason most experts recommend that uva ursi should not be used for more than a couple of weeks.

For more information, including dosage and safety issues, see the full Uva Ursi article.