A new study by UAB Fellow Jon Gleason, in the Division of Women's Pelvic Medicine and Reconstructive Surgery, showed that women who drink more than 329 milligrams of caffeine a day (which equals out to about three cups of coffee) are 70 percent more likely to suffer from urinary incontinence than those who don't. Gleason's findings were presented at the American Urogynecologic Society's annual meeting in Long Beach, Calif., Sept. 30, 2010.
Gleason said prior research had reported conflicting results about caffeine's effects on urinary incontinence because the studies were so small. He evaluated more than 1350 women ages 20 to 85 who participated in the 2005-2006 National Health and Nutrition Examination Survey. The women kept food diaries and answered questions about bladder function.
Gleason found no link between body mass index, vaginal childbirth or high water intake. Only higher levels of caffeine were associated with urinary incontinence.
Why is caffeine so hard on the bladder? Gleason said there is evidence that shows caffeine is a diuretic, increasing the amount of urine a person makes, and that it also stimulates the muscles that make a person void.