Regular low-dose aspirin has a protective effect against bowel cancer that is apparent after just one year and is effective in the general population, researchers from Western General Hospital, Edinburgh, found.
Previous work has established that NSAIDs protect against bowel cancer, but the lowest effective dose is unclear.
The team assessed 2279 people with bowel cancer, who were matched against 2907 controls.
Participants completed dietary and lifestyle questionnaires, and gave information on NSAID use.
NSAID intake was categorised as taking more than four tablets a month of low dose aspirin (75mg), other NSAIDs, or a mix.
Researchers then tracked participants for five years to assess impact of NSAID use on risk of developing bowel cancer and likelihood of survival.
They found low-dose aspirin use was associated with 22% reduced relative risk of lower colorectal cancer risk. The effects were evidence after just one year, and increased with duration of use.
Authors concluded that high aspirin or other NSAID use was not required for protection against bowel cancer. Furthermore, results were applicable to the general population and not just high-risk groups.