Researchers in Japan studied 14,646 volunteers between the ages of 60 and 85 years. The participants were randomly assigned to take a low-dose aspirin every day or not. According to the Journal of the American Medical Association, the trial ended after fiver years when it was clear that there were no significant differences between the two groups. Overall, 2.77% of those taking aspirin had a heart attack or stroke, compared to 2.96% among those not taking the drug. Via Time. Posted November 24, 2014.