Despite warnings, millions of seniors continue to use aspirin daily. A recent study revealed that 18.5 million older adults were still taking aspirin in 2021, with 3.3 million doing so without medical advice.

Many older adults take daily low-dose aspirin to help prevent cardiovascular disease, warding off heart attacks and strokes. While this was thought to be a good common practice for those who are at risk for heart disease, new studies show that this recommendation could come with some unwanted side effects.

The American Heart Association and the United States Preventive Service Taskforce have changed their guidelines around daily low-dose aspirin in recent years. Now, these companies are recommending that aspirin isn’t right for all patients and carries some serious risks for some.

In 2018, health authorities revised their guidance on aspirin use for those over 60.

“This practice was supported by evidence prior to 2018. It naturally takes some time for new data to percolate and reach physicians and patients and for these to translate into changes in management,” Mohak Gupta, MD, a Cardiology Fellow at Houston Methodist Hospital and First Author of the letter, told Healthline.

Aspirin has long been used to prevent heart attacks and strokes. Its blood-thinning properties help reduce clot formation, lowering the chances of cardiovascular events.

Aspirin impairs blood clotting, which can lead to severe and life-threatening internal bleeding.

Researchers analyzed data from 180,000 patients aged 40 and older between 2012 and 2021. This study, published in the Annals of Internal Medicine, shed light on aspirin use and its associated risks.

Gupta’s research used self-reported health data from 2012 to 2021, collected from a sample of 186,425 American adults, to represent the 150 million people who could be affected by this change.

For those who have already faced a heart attack or stroke, aspirin is a crucial ally. It can slash the risk of another cardiovascular event by about 25%.

Aspirin is a blood-thinner, which means that it has anticoagulant or antiplatelet properties that make it difficult for blood to clot.

However, adults 70 years and older, are still using aspirin daily. This is important to note because the risks of bleeding become more prominent with age.

“The kind of bleeding that led to the change in guidelines was all kinds of bleeding. So it is falling and hitting your head, but it’s a lot of spontaneous bleeding in the stomach,” Eleanor Levin, MD, a Clinical Professor of Cardiovascular Medicine at Stanford Medicine, told Healthline.

The authors of the study write their findings have real-world implications. The result could change regulations surrounding aspirin, and fill the knowledge gap about these changes among patients, particularly older ones.

“Doctors should engage in risk-benefit discussions with patients using aspirin for primary prevention, especially for adults 60 years of age and older, and discontinue aspirin where appropriate—such as in older patients, those at high bleeding risk,” said Gupta.

Aspirin is an affordable and accessible medication. Its low cost and easy availability contribute to its widespread use among seniors.

Compared to 10 years ago, fewer adults are using aspirin as the primary prevention of CVD, but the number of people using aspirin is still high.

3.3 million older adults were reportedly taking aspirin without any medical recommendation in 2021.

Health experts now recommend that individuals over 60 without prior cardiovascular events should avoid aspirin due to the risk of internal bleeding.

“When we’re talking about primary prevention patients, there’s a little bit more risk-benefit consideration. Are we more likely to prevent that first heart attack or stroke, or are we more likely to actually cause a major bleeding episode using aspirin?” Donald Lloyd-Jones, MD, past President of the American Heart Association and Professor of Preventive Medicine at Northwestern University’s Feinberg School of Medicine, told Healthline.

Doctors may still suggest aspirin for individuals with significant arterial plaque or those who have experienced a heart attack or stroke.

About 7% of adults over 60 have experienced a stroke, which means 5 million people. Meanwhile, 14% of those aged 65 to 74 have had a heart attack, affecting 4.6 million individuals.

While aspirin can cause other health issues, the study shouldn’t discourage you from taking it when needed.

Ultimately, the decision to use aspirin should be made in consultation with a healthcare provider. Considering the individual’s specific health history and risks is crucial.