Harard researchers used data from the Physicians' Health Study. a trial testing aspirin and effect on 22000 male physicians between the ages of 40 and 84. Half the physician are talking one aspirin (325 milligrams) every other day, while the other half take a placebo (inactive blank look - alike). After five year, the doctors talking the pain relieve report having twenty percent fewer migraines than the doctors talking the placebo