By Jonny Lupsha, Freelance News Writer

Cardiologists disavowed taking a low-dose aspirin per day to prevent heart attacks, Fortune reported, suggesting a placebo effect. Placebos affect the mind and body in many ways.

Recent guidelines for preventing cardiovascular disease were published in the Journal of the American College of Cardiology and notably omitted the decades-old recommendation. In fact, patients who do not suffer from heart disease and take one low-dose aspirin every day as a preventative face higher risks of internal hemorrhaging, the study said. Adults over age 70 who have followed the former recommendation to successfully prevent heart disease may have been benefiting from a placebo effect—but how do we define placebos, what do they do to the body and do they have valid use in modern medicine?

Defining and Understanding Placebos

Generally speaking, the placebo effect represents the brain-mind-body interactions that affect patients. “Any perceived response to a medical intervention other than a physiological response to an active treatment can be considered a placebo response,” said Dr. Steven Novella, Assistant Professor of Neurology at the Yale School of Medicine. “However, in reality, there isn’t one placebo effect; there are many placebo effects. It is anything that will cause the perception of benefit to an inactive treatment.” In other words, if the patient believes strongly enough that something will help them, then even if the item given to the patient is unrelated, they may report the benefits of its effects.

But why do they work? According to Dr. Novella, one psychological effect patients experience is called risk justification or expense justification. In this instance, the patient truly wants to get better, or they wish to please the person treating them, or they hope to justify the expense of the treatment. “They, therefore, want to justify not only their expenditures, but also the decision that they made,” Dr. Novella said.

Another reason is confirmation bias. Confirmation bias involves the theory that people will notice or remember things that confirm their own beliefs while ignoring or dismissing things that challenge them. “You may not be aware of the fact that you are systematically seeking out and remembering only that evidence that supports something which you already believe,” Dr. Novella said.

Real Benefits of Placebos

While very limited, there are some genuine benefits in using placebos. “Placebo effects can cause a genuine reduction in stress from non-specific and psychological aspects of the treatment—again, believing that you’re going to get better and the comforting attention of a therapeutic agent like a physician or other treater,” Dr. Novella said. Stress reduction can lower blood pressure, ease the strain on a patient’s heart and muscles, and diminish the perception of pain the patient feels.

Doctors used to practice sham surgery to induce a placebo effect in patients. Other times, patients are given “active placebos,” which produce an effect unrelated to the issue being treated. For example, a bitter-tasting medicine—or one that causes nausea—may convince the patient that it’s a real and effective medicine. However, in the age of “informed consent” of medical treatment, many placebos like these have been deemed unethical and are no longer practiced.

Understanding placebos helps to make sense of why the suggestion of taking a low-dose aspirin every day to avoid heart disease would affect patients. The suggestion may cause a perceived response, rather than an actual response, in patients who fear heart attacks. This response may be because patients want to justify their long-standing rituals of taking a daily aspirin. Also, it could be because patients are responding to the fact that their physicians recommended the suggestion of taking a daily low-dose aspirin, which confirms the patients’ existing biases and beliefs about taking an aspirin a day. Furthermore, when patients take what is believed to be necessary medicine, their stress levels tend to lessen, which genuinely helps to lower blood pressure and heart rate, in effect, becoming a sort of self-fulfilling prophecy for improved well-being.

Dr. Steven Novella contributed to this article. Dr. Novella is Assistant Professor of Neurology at the Yale School of Medicine. He earned his M.D. from Georgetown University and completed his residency training in neurology at Yale University. An expert in neuroscience, Dr. Novella focuses his practice on neuromuscular disorders.