Coffee, Sex, Nose-Blowing Linked to Strokes Exercise can also trigger ruptured aneurysm, study finds By Matt Cantor, Newser User Posted May 6, 2011 11:40 AM CDT 15 comments Comments Coffee may increase the risk of stroke, a study finds. (Shutterstock) (Newser) – A new study suggests some strange stroke risk factors: coffee, sex, exercise, and ... nose-blowing? All could lead to a burst blood vessel in the brain. The activities increase blood pressure, which boosts the risk of a ruptured aneurysm, says the Dutch study of 250 patients over three years. Coffee triggered more than one in 10 burst aneurysms, a high percentage that researchers attribute to how common, not how risky, an activity it is; in fact, coffee drinkers' risk was only 1.7 times greater than that of non-drinkers, the BBC reports. On the other hand, being startled multiplied the risk some 23 times, but was only at fault in 2.7% of aneurysm ruptures. “Vigorous exercise" was to blame in 7.9% of cases, nose-blowing in 5.4%, and sex in 4.3%. (TMI alert: "Straining to defecate" was blamed for 3.6% of cases.) But other stroke experts expressed doubts about the findings. “It's very difficult to determine whether the triggers identified in this study are definitely related to the onset of a stroke, as they could simply be put down to coincidence,” said one.