A California doctor named Lawrence Craven first noted this effect sixty years ago. He observed unusual bleeding in children who chewed on an aspirin product to ease the pain after a common operation.
Doctor Craven believed the bleeding took place because aspirin prevented blood from thickening. He thought">thought this effect might help prevent heart attacks caused by blood clots.
He examined the medical records of eight thousand aspirin users and found no heart attacks in this group. He invited other scientists to test his ideas. But it was years before large studies took place.
BARBARA KLEIN: Charles Hennekens of Harvard Medical School led one of the studies. In nineteen eighty-three, he began to study more than twenty-two thousand healthy male doctors over forty years of age. Half took an aspirin every other day. The others took what they
thought
was aspirin. But it was only a placebo, a harmless substance.
Five years later, Doctor Hennekens reported that people who took aspirin reduced their risk of a heart attack. But they had a higher risk of bleeding in the brain than the other doctors.
MARIO RITTER: In two thousand nine, a group of experts examined studies of aspirin at the request of federal health officials in the United States. The experts said people with an increased risk of a heart attack should take a low-strength aspirin every day.
Aspirin may help someone who is having a heart attack caused by a blockage in a blood vessel. Aspirin thins the blood, so it may be able to flow past the blockage. But heart experts say people should seek emergency help immediately. And they say an aspirin is no substitute treatment, only a temporary help.
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2013-11-25
2013-11-25
2013-11-25
2013-11-25
2013-11-25
2013-11-25