Harvard Health Blog
All too many women recognize the signals of urinary tract infections, or UTIs: pain and burning when urinating, coupled with a frequent urge to do so. A simple change in behavior could help prevent a common UTI known as recurrent cystitis in women, according to a randomized controlled study published in JAMA Internal Medicine in October 2018. The study showed that drinking more water daily led to fewer episodes of recurrent cystitis and less need for antibiotics.
What is cystitis and what causes UTIs?
Cystitis refers to an infection in the bladder, which most women know as a urinary tract infection. Cystitis is extremely common among women, partly because female anatomy increases the risk of infection due to the proximity of the urethra to the anus. Additional risk factors for cystitis include sexual intercourse, diaphragm use, spermicides and spermicide-coated condoms, and a prior history of cystitis. Women with diabetes and those who have abnormalities of the urinary tract are also at increased risk for cystitis.
The vast majority of infections (up to 95 percent) are caused by one bacteria, E. coli. Signs and symptoms of an infection include pain with urination, increased frequency of urination, and an increased urge to urinate.
What is the treatment?
Cystitis is treated with antibiotics for three to five days, depending on the antibiotic used.
Can UTIs be prevented?
If you’ve ever had cystitis, you may have heard suggestions that are mostly based on anecdotal evidence. To decrease risk for cystitis, women are advised to urinate after intercourse, drink cranberry juice, drink more fluids in general, and keep the perineal area that lies between the urethra and the anus clean. Evidence is mixed on whether these steps may help prevent cystitis. This study sought to provide direct evidence of the benefits of drinking extra fluids.
What did the study tell us?
The study participants were 140 premenopausal women who experienced three or more episodes of cystitis in one year and reported that they drank less than 1.5 liters of fluids daily, which is about 6 1/3 cups. The average amount participants drank daily was a bit over a liter (1.1 liters, or about 4 1/2 cups).
The women were randomized to one of two groups. Every day, one group drank their usual amount of fluids plus an additional 1.5 liters of water. The control group drank just their usual amount of fluids. The women kept journals recording the type and amount of fluids they drank in a day. Their urine was periodically measured for volume and tested for hydration status. The study discovered that women who drank an additional 1.5 liters of water had 50 percent fewer episodes of recurrent cystitis, and required fewer antibiotics than women who did not drink additional fluid.
Is it safe to drink this much fluid?
While the amount of extra fluids tested in the study may seem like a lot, the Institute of Medicine recommends that women have 2.2 liters daily, which is about 9 cups. Not all of this needs to come just from water — or even fluids. Fruits and vegetables, which are part of a healthy diet, contain a lot of water.
This study used a rigorous scientific method to evaluate the benefits and risks of an inexpensive and safe anecdotal treatment. While it has been suggested that substances in cranberry juice can decrease the risk of urinary tract infection, no studies have conclusively demonstrated its benefits. Water may be the best means to increase hydration because it is inexpensive and has no calories. Although this study focused on women who had recurrent cystitis, its results could be extrapolated for a lower-risk population as well.
If you’re a woman with symptoms of cystitis, such as pain or burning with urination, increased urgency and frequency, try to drink more fluids, but also call your health care team for evaluation. A simple urine test in conjunction with the symptoms you describe may provide enough information for your health care provider to confirm an infection and start you on a brief course of antibiotics.
Better still, going forward, you may be able to decrease the chance that you will develop an infection by drinking more water daily. It’s a simple solution readily available for prevention — and now supported by evidence!
(Huma Farid, M.D., is a contributor to Harvard Health Publishing.)