People over the age of 50 should take aspirin every day to reduce their risk of getting a heart attack or a stroke, according to new research.Dr Peter Elwood and colleagues in the Welsh Aspirin Group at Cardiff University in Wales say that about 80% of men and 50% of women in the UK aged 50 and older are already deemed to be at an increased risk of having a vascular event such as heart attack or stroke in the next five years.