As we get older, we must take care of ourselves. An injury that might have been minor in our younger days can be serious later in life. Preemptively taking steps to protect our health can make us feel contented. It’s great to feel the satisfaction of knowing you’re taking care of yourself. It can really give you a bounce in your step. However, one piece of long-accepted proactive health advice may be wrong: instead of helping your heart, aspirin may be detrimental to your body.

A study from Harvard Univ. and Beth Israel Deaconess Medical Center showed that prophylactic aspirin might do more harm than good. Their study found that, in 2017, approximately 29 million people over the age of 40 who didn’t have heart disease took an aspirin a day to prevent heart attacks. Of those people, 6.6 million were never told to take preventative aspirin by a doctor. Almost 10 million people over 70 who were taking preventative aspirin to stave off a heart attack didn’t have heart disease.

These 29 million people are taking aspirin, despite not having heart disease, in the face of extensive studies that have shown that an aspirin a day may only have a very small — if nonexistent — benefit. Meanwhile, low-dose aspirin can heighten the risk of intracranial bleed, or bleeding inside the skull, for people who don’t have the disease.

In light of this study, the American Heart Association and American College of Cardiology has, in fact, changed their guidelines.

“Clinicians should be very selective in prescribing aspirin for people without known cardiovascular disease,” said Roger Blumenthal, co-chair of the 2019 ACC/AHA Guideline on the Primary Prevention of Cardiovascular Disease. “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.”

Unfortunately, this aspect of self-care has been proven to be detrimental. “Many patients are confused about this,” said Colin O’Brien, a senior internal medicine resident at Beth Israel who led the study. “We hope that more primary care doctors will talk to their patients about aspirin use, and more patients will raise this with their doctors.”

Speak to your doctor before making any changes to your daily routine, your doctor knows your medical history and can give you better, personalized advice than basic guidelines from the ACC/AHA. Maybe you can cut the aspirin out of your morning routine!