Daily Aspirin Not Recommended for Bowel Cancer Prevention in Average-Risk Adults

A new Cochrane review released in February 2026 indicates that daily aspirin use is not a reliable or quick method for preventing bowel cancer in the general population of people at average risk.

The analysis suggests that while some may use the medication as a preventative measure, any potential protective effects are uncertain and slow to emerge. In contrast, the risk of serious bleeding begins immediately, even when low-dose aspirin is used.

Study Methodology and Scope

Researchers from West China Hospital of Sichuan University in China conducted the review, analyzing 10 randomized controlled trials. These trials included a total of 124,837 participants.

The team assessed whether aspirin or other nonsteroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen, could prevent colorectal cancer or precancerous polyps, known as adenomas, in individuals at average risk.

While the researchers investigated various NSAIDs, they found no suitable trials for non-aspirin medications. The conclusions of the review focus exclusively on the use of aspirin.

Short-Term Risks and Long-Term Uncertainty

The review found that aspirin probably does not reduce the risk of bowel cancer during the first 5 to 15 years of use. This suggests that the medication does not provide a short-term preventative benefit.

Some studies observed possible protective effects after more than 10 to 15 years of follow-up. However, the researchers noted that the certainty of this evidence is very low.

These potential long-term benefits were derived from observational follow-up phases of the trials. During these phases, participants may have started other treatments, stopped taking aspirin, or begun taking it independently, which makes the findings vulnerable to bias.

While the idea of aspirin preventing bowel cancer in the long run is intriguing, our analysis shows that this benefit is not guaranteed and comes with immediate risks.

Dr. Zhaolun Cai, lead author

Medical Context and Prevention

Bowel cancer, also referred to as colorectal cancer, is among the most common cancers globally. Standard prevention typically focuses on routine screening tests and maintaining a healthy lifestyle.

The role of NSAIDs in primary prevention has remained a subject of debate among scientists. While these drugs are commonly used to treat fever, inflammation, and pain, their effectiveness in preventing the development of colorectal cancer remains uncertain.

Because the risk of serious bleeding is immediate and the preventative benefits are weak or delayed, experts warn that decisions regarding aspirin use for cancer prevention should be individualized rather than automatic.