Millions take aspirin to prevent colon cancer. A major review says dont count on it

Daily aspirin does not reliably prevent bowel cancer in people at average risk, according to a major new review. Any potential protective effect may take more than a decade to appear - if it appears at all - and the evidence for that benefit is weak. In contrast, the risk of serious bleeding begins right away, even with low-dose aspirin. Experts warn that prevention decisions should be individualized, not automatic.