Aspirin has been prescribed for years to prevent heart attacks.
Heart attacks are caused by blood clots that block arteries narrowed by plaque build up.
Meanwhile Aspirin reduces your blood’s ability to clot.
Theoretically, scientists thought that this should reduce your chances of getting a heart attack, which is why doctors have prescribed aspirin for decades as a preventative measure.
However, the question of whether this actually saved lives was not fully studied, until now.