For every life the drug may potentially save, it also increases the risk of internal bleeding and stroke, researchers from Warwick Medical School have concluded, after reviewing 2,572 papers.
In short, it's a fine line between benefit and risk, they say, although the figures they uncovered may not bear out that conclusion.
Overall, they reckon that regular aspirin use has saved between 33 and 46 deaths from heart disease and up to 34 deaths from colorectal cancer in 100,000 people over a 10-year period. However, over the same period, the drugs have caused up to 46 major bleeds and 117 gastrointestinal bleeds in 100,000 people.
(Source: Health Technology Assessment, 2013; 17: doi: 10.3310/hta17430)