If you're one of the millions of US adults taking aspirin daily as a preventative measure, two new studies have bubble-bursting news: Doing so may not do any good—and could actually cause harm. Researchers in both studies found that even low-dose aspirin carries a risk of internal gastric bleeding, and the newer study also found that older patients who were not at high risk of cardiovascular disease saw no health benefits from taking aspirin daily. "We knew there would an increased risk of bleeding," a study co-author tells NBC News (aspirin is a blood thinner). "But not only did it not decrease risk of disability or death, it did not decrease the risk of heart attack and stroke, and there was an increase in the rate of death." Aspirin has been widely used in healthy older adults to protect against cardiovascular disease and cancer.
But the new international study followed 19,114 seniors for an average of 4.7 years. It found similar survival rates as well as rates of disability, dementia, coronary heart disease, heart attacks, and strokes for the half taking 100mg of aspirin daily and the half taking a placebo. But internal bleeding (hemorrhagic stroke, bleeding in the brain, gastrointestinal bleeding, and other bleeding) was found in 3.8% of patients taking aspirin versus 2.7% of those taking a placebo. There was also a small increase in the number of cancer deaths in the aspirin-treated group, the New York Times reports. One cardiologist not involved with the study notes that in the time since the original research on aspirin was done, patients can now take other medications to lower cholesterol and blood pressure, and suggests it's time to "phase out" the broad use of preventative daily aspirin. (Read more aspirin stories.)