Women with frequent urinary tract infections (UTIs) may be able to reduce the number of subsequent infections they have by simply turning on the kitchen tap or office water cooler and drinking more water throughout the day, according to new research published Monday in JAMA Internal Medicine.
The study found that women with a history of UTIs (also known as cystitis) who drink at least four 12-ounce glasses of water a day tend to have fewer infections over a 12-month period than those who drink less than that amount.
Scientists believe water may help protect against UTIs by diluting and then flushing out bacteria from the urinary tract before an infection can take hold.
“Our data confirm the benefit of increased water intake in reducing the risk of recurrent cystitis in women with a history of frequent recurrent cystitis who are low-volume fluid drinkers,” the authors of the current study conclude.
A major factor in antibiotic use
As background information in the study points out, UTIs are common in women. A woman’s lifetime risk of developing a UTI is greater than 50 percent, and recurrent infections are also quite likely. One in four women has at least one recurrence within six months of her first infection, and up to 70 percent have a recurrence within 12 months.
Symptoms include an urgent need to urinate, a burning sensation while urinating, cloudy or discolored urine, strong-smelling urine and pelvic pain.
UTIs are usually treated with antibiotics. Because these infections are so common, it’s been estimated that 15 percent of antibiotics used in humans are for the treatment of UTIs — a factor that likely contributes to the urgent and growing global problem of antibiotic-resistance, the study’s authors point out.
Women have long been advised to stay hydrated to decrease their risk of UTIs, but the few studies that have investigated that advice haven’t been definitive.
A team of international researchers decided to conduct what they say is the first randomized controlled trial to test the idea that drinking more water offers protection against UTIs. They recruited 140 healthy Bulgarian women (mean age: 35.7 years) who had experienced within the previous year at least three UTI episodes that had resulted in a visit to a physician.
All of the women were also “low-volume drinkers.” They consumed less than 1.5 liters — or about six cups — of fluid daily, as determined by a three-day fluid intake diary and a 24-hour collection of urine.
The women were randomly divided into two groups. One group (the “control”) was not given any advice about their fluid intake. The other group was instructed to drink 1.5 liters of water daily in addition to their usual intake. The water was provided to them in bottled form.
The women were followed for a year. During that period, most of the women experienced another UTI. But the women in the “water” group averaged half as many infections as those in the control group: 1.7 versus 3.2.
In total, there were 111 UTIs among the women who purposely increased their water intake compared to 216 among those who didn’t.
Given those numbers, it’s not surprising that the average number of antibiotic treatments during the study period was also lower among the women in the “water” group (1.9 treatments) than in the control group (3.6 treatments).Furthermore, the interval between recurrent UTI infections was longer for the women who drank the additional water: 142.8 days, on average, compared to 84.4 days, on average, for the control group.
“It seems appropriate for clinicians who counsel healthy women with recurrent cystitis to routinely ask about daily fluid intake and to recommend increased intake of water, especially in those who drink no more than 1.5 [liters] of fluids daily,” the authors of the study conclude.
Limitations and implications
The study can’t say how much water women with a history of UTIs should drink to lower or delay their risk of developing another infection, particularly if they aren’t “low-level” drinkers, like the women in this study.
Nor can the study say if women who aren’t at high risk of UTIs would benefit from drinking more water.
And although most people can up their water consumption without any harm, experts also warn about overhydrating. Drinking too much water can lead to abnormally low levels of sodium in the body and a potentially life-threating condition known as hyponatremia.
The current study comes with some other important caveats. It involved a relatively small number of women living in a particular location in one country. The findings may not be applicable, therefore, to women living elsewhere.
In addition, the research was funded by a company that sells bottled water, including the brand used in the study. Industry-funded studies tend to have a bias in favor of the products the industry sells.
But, as Dr. Deborah Grady, an epidemiologist at the University of California, San Francisco and a deputy editor at JAMA Internal Medicine, points out in an editorial that accompanies the study, when it comes to preventing UTIs, “any safe-to-drink water will do, including your local tap water.”
Drinking tap water “will also spare the environmental impact of bottled water and improve the cost-effectiveness of the intervention,” she adds.
FMI: You’ll find an abstract of the study on the website for JAMA Internal Medicine, but the full study is behind a paywall.