The amount of caffeine that's typically found in two cups of coffee may contribute to a man's incontinence, according to a new study.
"It's something to consider... People who are having problems with urinary incontinence should modify their caffeine intake and I think that's part of clinical practice," said Dr. Alayne Markland, the study's senior author, from the University of Alabama at Birmingham.
Though the report doesn't prove that caffeine causes bladder leakage, the men in the study who consumed the most caffeine were more likely to have the problem than those who took in the least.
Plenty of research has linked caffeine to incontinence among women. But little is known about whether there is a similar connection for men.
"We wanted to see if caffeine had an impact on them as well," said Markland.
It's estimated that 85 percent of Americans consume caffeine regularly, both in beverages like coffee, tea and soft drinks, and in foods like candy, pastries and ice cream containing chocolate.
Estimates of urinary incontinence among U.S. adult men range from 5 percent to 21 percent.
For the new study, published in The Journal of Urology, Markland's team used responses from about 4,000 men to a national health survey between 2005 and 2008. The researchers looked at how many had urinary incontinence and how much caffeine they ate or drank, as well as how much water they took in from both foods and beverages.
Overall, the men consumed an average of 169 milligrams of caffeine every day. That's a little more than the typical 125 milligrams found in a cup of coffee.
About 13 percent of the men reported leaky bladder, but only 4.5 percent had a problem considered moderate or severe - which is more than a few drops of urine leakage during the course of a month.
After adjusting for the men's age and other risk factors, the researchers found that those who ate or drank 234 or more milligrams of caffeine every day were 72 percent more likely to have moderate to severe urinary incontinence than those who consumed the least caffeine.
Men who downed more than 392 milligrams of caffeine daily were more than twice as likely to be incontinent.
Total water intake, in contrast, was not linked to a man's risk of moderate to severe incontinence.
It's not just a matter of how much fluid a person takes in. Markland told Reuters Health that some research in women suggests caffeine irritates the bladder, and she believes that may also underlie the association in men.
"Although we didn't prove that in the study, that condition has been documented in women and we may need further evaluation in men," she said.
Dr. Bryan Voelzke, from the Department of Urology at the University of Washington Medical Center in Seattle, said the medications men take, such as diuretics, could also affect their bladder control.
"I think the findings are interesting," said Voelzke, who was not involved in the new research. But the next step, he added, is to design a study that follows men going forward to better understand all the factors that may contribute to the problem.
This study on its own is not enough to say caffeine is the source of urinary incontinence, according to Voelzke.
"I think - if anything - it's a suggestion. I don't think it's a call for action to stop drinking coffee," he said.