Is taking a daily aspirin smart or dangerous?

A daily low-dose aspirin is a proven protection for some people and a real risk for others. Based on large studies, the American preventive health task force USPSTF has issued clear recommendations for both situations. These differ considerably by age group.

If you are between 40 and 59 years old with an elevated cardiovascular risk, specifically a 10% or greater chance of a heart attack or stroke within ten years, the evidence shows a small but real benefit. The USPSTF does stress that this is a personal decision. People who have no elevated bleeding risk and take aspirin consistently have the greatest chance of a net benefit. The effect is modest, not spectacular.

Are you 60 or older without known cardiovascular disease? Then the USPSTF message is unambiguous: do not start. The risk of serious bleeding, such as in the stomach or brain, outweighs the possible benefits. That is not a cautious assumption but an explicit conclusion based on multiple studies in humans¹.

Around non-cardiac surgery, routine aspirin use is also inadvisable. Studies in humans show that it does not reduce the chance of cardiac complications but does increase the risk of bleeding during the procedure².

There are situations in which aspirin is clearly beneficial. In pregnant women at high risk of pre-eclampsia, low-dose aspirin lowers the risk of that complication, of preterm birth, and of harm to mother and child^3,4. In the rare platelet disorder essential thrombocythemia, aspirin is recommended to prevent blood clots. European gastrointestinal specialists also state that aspirin may offer some protection against stomach cancer in people who already have a high cardiovascular risk, although that evidence is more limited and explicitly applies to a select group.