Does caffeine contribute to a leaky bladder? Researchers have long debated the issue, with studies turning up conflicting evidence; however, more recent research shows there might be a link between high caffeine consumption and urinary incontinence.
The study involved more than 65,000 U.S. women ages 37 to 39 who were part of the Nurses’ Health Study. They measured daily caffeine intake and found that women with a high caffeine intake (defined as 4 or more cups of coffee or 10 or more cans of soda) were more likely to develop urinary incontinence during the 4-year period than their less-caffeinated counterparts. In fact, the women with the highest caffeine intake were 19 percent more likely than the least caffeinated to develop bladder problems at least once a week or more often.
The researchers are quick to note that the link is not proof of causation. They only saw an increase in urinary incontinence in women who consumed 450 mg or more of caffeine per day, which indicates that high amounts of caffeine might be the culprit—since there was no increased risk among women who consumed less caffeine.
The urinary incontinence in the women with high caffeine consumption was referred to as urge incontinence (or urgency), which is a type of incontinence where leakage happens after a sudden, strong urge to urinate.
Urinary incontinence is about twice as common in women as men. Obesity and vaginal childbirth increase the risk for urinary incontinence. Researchers continue to evaluate the link between caffeine and incontinence; one theory is that caffeine can speed muscle contractions in the bladder.
So far, the data from this and other studies is not enough to provide a basis for advice regarding caffeine intake; however, it can never hurt to cut back. If you think you’re at risk of developing urinary incontinence, avoiding high doses of caffeine can’t hurt and might help.
 Jura Y, Townsend M, Curhan G, et al. Caffeine intake and risk of stress, urgency, and mixed urinary incontinence. The Journal of Urology. 2011; 185(4) supplement e405.