Women with urinary incontinence who also enjoy their regular cup of coffee or tea don't have to worry about the extra caffeine making their condition worse, suggests a new study.

The new research published in Obstetrics & Gynecology, May 2012 stands in contrast to the common recommendation that women with continence issues stay away from caffeinated foods and beverages.

"If a woman feels she wants to abstain from caffeine that's completely fine, but based on our results, women with moderate incontinence shouldn't be concerned," said Mary Townsend, the study's lead author from Brigham and Women's Hospital and Harvard Medical School in Boston.

Still, the findings cannot say whether caffeine might have a shorter-term impact by making women need to urinate soon after eating or drinking something caffeinated.

According to Townsend, there are some biological reasons that may prompt women with incontinence to stay away from caffeine,  i.e. that it increases the production of urine and may give some the urge to go. But it's been unclear whether a daily caffeine habit is tied to worsening incontinence over the long run.

To try to answer that question, the researchers looked at data on about 21,500 women enrolled in two large studies, each of which tracked the long-term health of U.S. nurses through surveys starting in the 1970s or 1980s.

Townsend and her colleagues selected women with light incontinence, defined as leaking urine one to three times per month , from participants who were asked about incontinence and caffeine consumption in 2002 or 2003.

The women were questioned about how much caffeine they ate or drank in the form of coffee, tea, soda or chocolate over the previous few years.

Two years later, when they were again surveyed about incontinence, about 20% of women said their symptoms had deteriorated and they now leaked urine at least once per week. This was consistent regardless of how much caffeine they'd reported eating and drinking.

The researchers also didn't find a link between women who increased their caffeine consumption between the survey years and worsening urinary symptoms, either for general incontinence or for overactive bladder in particular.

Townsend said most women in the study did not even tell their doctors about their incontinence.

She also said the new findings, need to be confirmed with more research because there's a possibility that caffeine could make urinary symptoms worse over longer than a few years.

The study was also limited because incontinence symptoms were reported by the women themselves and not measured by a doctor, and the researchers didn't take treatment for incontinence into consideration.