The Food and Drug Administration is recommending against taking an aspirin a day to prevent a heart attack.  FDA researchers say the risk of internal bleeding is the primary concern.

"Bleeding from the stomach is quite common, more rarely bleeding in the brain. So, if you have a low risk of a heart attack then the bleeding risk may overwhelm any potential benefit of aspirin," explained Cleveland Clinic Cardiologist Dr. Steve Nissen, who was not part of the study.

Bissen says aspirin thins the blood, which would make it less likely to clot.
clotting is associated with heart attacks, so the logic was taking an aspirin a day would help to prevent heart attacks. But FDA researchers say they've carefully examined major studies and conclude the data does not appear to support the use of aspirin as a preventative medication by people who have not had a heart attack, stroke, or cardiovascular problems.

Nissen says there are only a select few who may benefit from aspirin therapy.

"It's somebody that has every risk factor: high blood pressure, high cholesterol, strong family history, diabetes, if you have all of those things- smoking. If you have all of those risk factors, then some of those people we will treat with aspirin, but it's not very many," said Nissen.

Even if you only have one of the risk factors, like a strong family history, FDA researchers say the data do not show a benefit from aspirin therapy. They say their recommendation applies to doses ranging from 80 milligrams in a low-dose tablet to the 325 milligrams in a regular strength tablet.

Nissen says if you're taking aspirin to prevent a heart attack and have never had heart disease, or a heart attack before, talk to your doctor.

"If you're in doubt talk to your physician, frankly, you know, self-medication is almost never a good idea, whether it be aspirin or anything else, it's always a good idea to talk to your doctor," he said.

FDA researchers say your doctor can tell you the dose and frequency that will provide the greatest benefit with the least side-effects, for aspirin, or any medication.