Aspirin May Not Help If You Haven’t Had a Heart Attack

aspirin pills

After starting its life as a painkiller, aspirin has quickly become a go-to drug for those with symptomatic heart disease. It works by blocking the activity of certain proteins that are key to starting the inflammatory process, which is how it blocks pain after a variety of insults to the body. Within that family of proteins is one used by platelets, the clotting cells of your blood. When aspirin enters the bloodstream, it makes it harder for platelets to stick together and clot, thereby “thinning” the blood.

Because of this ability, aspirin has become an essential part of preventing clot risk in those with a history of a heart attack or other clotting event like a stroke. With aspirin being so easily available with apparently few side effects, some doctors have started recommending that patients at risk for these conditions take low-dose aspirin. But as a new study this week points out, there’s much less evidence that this is an effective way to prevent disease than you might think.

The researchers noticed the small but growing trend toward using aspirin in patients with no history of symptomatic heart disease and wanted to see if taking aspirin would decrease how likely a person would be to have a heart attack or stroke from a clot. To do this, the researchers enlisted 14,464 patients between 60 and 85 years old from across Japan. Half of the patients were given a daily low-dose aspirin and the others were not. The researchers then looked to see how many suffered from a heart attack or stroke over the next several years.

While the study was meant to run for up to six and a half years, the researchers analyzed all data gathered at both one and three years to get a sense of what might be happening. The researchers didn’t see any difference between those taking aspirin and those who weren’t and decided to stop the study after only five years.

The researchers acknowledged that letting the study go on for the full six and half years might have eventually shown a benefit to taking aspirin. But they point out that most patients without a heart attack history who had started using aspirin assumed they’d see a quick and dramatic effect similar to that seen in heart attack patients. This was not the case. If there’s any benefit from giving aspirin to people who haven’t had a stroke or heart attack, it’s very small.

All decisions about whether or not to take a medication should be made in partnership with a physician, and this study doesn’t mean you should or shouldn’t be taking aspirin. This study is important because it reins in some of the enthusiasm about aspirin that can lead to overprescribing it. While aspirin is generally safe, it can lead to bleeding in the stomach and has been shown in at least one major study to increase a person’s risk for a major bleeding in the brain, stomach or intestines. In this study, about 70 more patients ended up with bleeding in their stomach as a result from aspirin. These events aren’t common, but can be deadly. As such, studies like these help physicians understand the benefits of a drug like aspirin so they can weigh it against the risks of taking it.