Overview
- The systematic review pooled ten randomized trials with about 125,000 average-risk participants from Europe and North America, including seven low-dose (75–100 mg/day) and three higher-dose aspirin studies.
- Across 5 to 15 years of follow-up, the analysis found no reduction in new colorectal cancer cases, with any possible protection after 15 years remaining uncertain.
- Regular aspirin use increased bleeding risks, including intracranial hemorrhage, and raised stroke risk, with older adults and people with pre-existing conditions particularly vulnerable.
- Study authors Zhaolun Cai and Dan Cao advise against broad population use for prevention and recommend weighing risks and benefits with medical guidance.
- Independent experts note aspirin’s delayed effects and emphasize proven steps such as screening from age 50 and healthier lifestyles, as German data show declining incidence and a 17% drop in deaths over 20 years.