A November 2017 study by the University of George concludes that,
“We shouldn't just assume that everyone will benefit from low-dose aspirin, and in fact the data show that the potential benefits are similar to the potential harms for most people who have not had a cardiovascular event and are taking it to try to prevent a first heart attack or stroke,"
"If you look back in the 1970s and '80s when a lot of these original studies were done, patients were not taking statin drugs to control cholesterol, their blood pressure was not as well controlled, and they weren't getting screenings for colorectal cancer."