The heart health benefits of aspirin are unique to the drug, and is often recommended to help prevent heart attacks.
Aspirin may have multiple effects, but it is likely that its impact in cutting the stickiness of blood platelets is its major role in preventing heart attacks.
Acetaminophen had no effect on the stickiness of blood platelets and ibuprofen had only a transient effect.
A heart attack occurs when sticky platelets close an artery. Aspirin has its effect by blocking an enzyme by binding to it and blocks the compounds that make the platelets sticky in an irreversible way.
The same compounds, called prostaglandins, are also involved in the pain response. Tylenol and other brands of acetaminophen block pain in an entirely different way.
After exposure to aspirin, platelets can’t produce the enzymes for the rest of their lives, about ten days.
Most cells have a nucleus, which acts as a “brain” to direct cell functions, but platelets are just little packets of cellular protein with no nucleus to tell the cells to make more protein.
About 10 percent of platelets turn over each day, and it takes a few days for platelet function to get back to normal, so an aspirin every other day works just as well for the heart.
As for who should take aspirin, some questions remain.
It is known to benefit those who have had heart disease or a stroke, and there is suggestive evidence that a segment of the healthy population will benefit as well.
Studies have found that even healthy men will benefit, and most of the benefit is in men older than fifty.
Studies are under way to explore the risks, benefits and side effects of aspirin for others.
One study includes forty thousand women, who are taking 100 milligrams, about a third of a standard 325-milligram aspirin, every other day.