Taking medications containing caffeine was tied to a doubled or even tripled risk of having a stroke in a new Korean study that might seem to contradict recent evidence suggesting coffee and tea exert protective effects.
But the results may be in fact be in line with that research, according to the study authors, who point out that people who drank the least coffee were most at risk when taking caffeinated drugs.
The products included mostly over the counter pain relievers, cold medicines and alertness aids containing small amounts of caffeine.
"Caffeine is a vasoconstrictor, causing blood vessels to tighten and increasing the pressure of the blood flow," Nam-Kyong Choi of Seoul National University College of Medicine, who co-led the study, said in an email
That effect on blood pressure could explain the possible link to strokes, but the study didn't investigate the mechanism, Choi said.
The researchers selected 940 adult patients who had suffered a hemmorhagic stroke, wherein a blood vessel in the brain bursts and bleeds heavily.
They then compared those patients to a group of similar people who had not suffered a stroke but had been hospitalized, and to a third group who had neither suffered a stroke nor been hospitalized.
The team interviewed all the participants about all medications they had taken in the preceding two weeks.
They found that overall, those who had taken a medication containing caffeine were about two and a half times more likely to suffer a stroke, according to the results published in the journal Stroke.
Five percent of people who had had strokes had taken a caffeine medication, compared to 2.3 percent of the no-stroke groups.
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Common meds containing caffeine may be linked to stroke