A daily low dose of aspirin can safeguard against the chances of suffering or dying from bowel cancer, research has shown.
Scientists who analysed data on more than 14,000 patients found that taking the painkiller over several years reduced the chances of developing Britain's third most common cancer by a quarter.
It also cut the number of deaths from the disease by more than a third.
The effective doses of the drug were relatively low, ranging from 75 to 300 milligrams.
Previous research had suggested regular high doses of more than 500 milligrams of aspirin can reduce bowel cancer rates. But over-exposure to aspirin can lead to potentially dangerous side effects, such as internal bleeding and stomach ulcers.
Researchers gathered data from four randomised aspirin trials conducted to investigate the prevention of artery disease.
On average, patients were men and women in their sixties who took the pill for six years.
Over a period of around 20 years, 391 of the trial participants, or 2.8%, developed bowel cancer. Aspirin was shown to reduce the risk of the disease by 24% and cut death rates by 35%.
The results were published in The Lancet medical journal.
Lead researcher Professor Peter Rothwell, from Oxford University and the John Radcliffe Hospital, said: "Our findings suggest that long-term low-dose aspirin treatment and sigmoidoscopy screening would combine to substantially reduce cancer incidence in all parts of the colon and rectum."