Low-dose aspirin is used to prevent stroke and heart disease. However according to a new report, the study shows low-dose aspirin is linked with an increased risk of bleeding in the skull in those without a history of those conditions stated.

Researchers analyzed data from 13 previous studies in which around 130,000 people between ages of 42 to 74, who did not have a history of stroke or heart disease, were given either low-dose aspirin or placebo for the prevention of the stated conditions.

An aspirin is defined as a low dose if it is between 75 and 100 milligrams but most over the counter pills are around 81 milligrams. Those who took the placebo had a 0.4% risk of having a head bleed during the combined trial periods. For those who took low-dose aspirin, the risk was 0.63%, which is the equivalent of an additional 2 out of every 1,000 people developing a bleed, according to the study that was published on Monday in the journal JAMA Neurology.

People from Asian backgrounds and those who have a body mass index under 25 had the highest risk. Taking low-dose aspirin daily was formerly recommended for older adults because of the medicine's known ability to prevent platelets from forming a clot. In those who have fatty deposits in their arteries, known as atherosclerotic plaques, it can break off and trigger clotting, preventing the blood flow to the heart or brain.

Although aspirin would stop the process, previous studies had offered evidence that conflicted the evidence on whether taking it could increase the risk of bleeding in the skull. The three recent studies concluded that taking a low-dose aspirin every day is a waste of money for older adults. It may raise their risk of internal bleeding and early death as well.

Because of this study, aspirin is no longer recommended as a preventive measure for older adults who do not have a risk of or existing heart disease, according to guidelines announced by the American College of Cardiology and American Heart Association.

"Clinicians should be very selective in prescribing aspirin for people without known cardiovascular disease," Johns Hopkins cardiologist Dr. Roger Blumenthal, who co-chaired the March guidelines, said in a statement. "It's much more important to optimize lifestyle habits and control blood pressure and cholesterol as opposed to recommending aspirin."

"Aspirin should be limited to people at the highest risk of cardiovascular disease and a very low risk of bleeding," he said.