Aspirin, when taken every other day for at least 10 years, decreased colon cancer in women by 20%. Women who took 100 mg of aspirin every other day were found to have this benefit. The study was specifically performed in women, so a male benefit is unknown.
This was published in Annals of Internal Medicine and is a follow up to an earlier study which didn’t find a cancer difference. This shows that this benefit does not “kick in” until about 10 years after the start of regular use. Of note, there are known side effects of taking aspirin. Aspirin can cause serious, even occasionally fatal, stomach bleeding, even at low doses.
The American Cancer Society does not recommend that people use aspirin specifically to prevent cancer.
Interesting finding. . .