"The Food and Drug Administration (FDA) is warning people that a daily aspirin regimen may not help prevent a heart attack or stroke, and may cause dangerous bleeding into the BRAIN or stomach.

Although a daily low dose of aspirin has been shown to be effective in preventing a reoccurrence of a heart attack or stroke, the FDA is now warning people who have not had a first heart attack or stroke that taking an aspirin every day may not have a benefit. In fact, doing so may actually cause serious side effects.

However, following examination of scientific data from major studies, the FDA has concluded that the data do not support the use of aspirin as a preventive medication by people who have not had a heart attack, stroke, or cardiovascular problems, a use that is known as primary prevention. In these people, the benefit has not been established, and risks, such as dangerous bleeding into the BRAIN or stomach, are still present." 
                FDA, 2014