LONDON, Aug. 6 (Xinhua) -- Taking aspirin can significantly reduce the risk of developing and dying from major cancers of the digestive tract including bowel, stomach and esophageal cancer, according to a large-scale British study published Wednesday.
It added that its benefits outweighed any harmful effects.
Aspirin is a common, cheap medicine taken by many to prevent heart attacks and strokes. Previous studies suggested that it could help reduce the risk of some cancers.
However, some experts were concerned that it caused side effects such as ulcers. Aspirin is not recommended for healthy people as cancer prevention medicine.
In the new research, published in the leading cancer journal Annals of Oncology, Queen Mary University of London (QMUL) scientists reviewed available evidence from about 200 studies and clinical trials, assessing both the benefits and harms of the preventive use of aspirin.
They found taking aspirin for 10 years could cut bowel cancer cases by around 35 percent and deaths by 40 percent. Rates of esophageal and stomach cancers were cut by 30 percent and deaths from these cancers by 35 to 50 percent.
Evidence showed that people need to start taking a daily dose of 75-100 mg for at least five years and probably 10 years between the ages of 50 and 65. No benefit was seen whilst taking aspirin for the first three years, and death rates were only reduced after five years.
The research also warned taking aspirin long-term increases the risk of bleeding from the digestive tract. Among 60-year-old individuals who take daily aspirin for 10 years, the risk of digestive tract bleeds increases from 2.2 percent to 3.6 percent.
"Whilst there are some serious side effects that can't be ignored, taking aspirin daily looks to be the most important thing we can do to reduce cancer after stopping smoking and reducing obesity," Professor Jack Cuzick from QMUL commented.
He added further research is needed to define more clearly who will most benefit from taking aspirin and who is most at risk of side effects.