Key points from article :
Elderly people in good health should not take an aspirin a day.
Large trial found no benefit for healthy people over the age of 70.
But the pills increased the risk of potentially fatal internal bleeding.
There are proven benefits for people after a heart attack or stroke.
Most research on aspirin is performed on people in middle age.
Study of nearly 20,000 over 70s with no history of heart problems.
The studies were published in The New England Journal of Medicine.