An aspirin a day keeps the doctor away? Not so fast.

By Eric Verdin, President and CEO of the Buck Institute

A daily aspirin regimen has long been touted as a safe way to keep your heart healthy and lower your risk for cardiovascular disease and cancer. But a recent series of studies published in The New England Journal of Medicine suggests that regular aspirin use may have more risks and less benefits than previously thought, particularly for healthy adults. These findings are the first published from the ASPirin in Reducing Events in the Elderly (ASPREE) trial jointly supported by the National Institutes of Health and the Australian National Health and Medical Research Council.

The study, led by John McNeil of Monash University and Anne Murray of the Berman Center for Outcomes and Clinical Research, enrolled over 19,000 adults aged 70 and older (65+ for Hispanic and African-American participants) in a randomized, placebo-controlled trial to observe the health outcomes of daily, low-dose aspirin use over an average 4.7 year span. Participants who were randomly assigned to the aspirin-treatment group took a low dose (100mg) of aspirin each day. The study found that the group taking aspirin had a slightly increased risk of death (5.9%) compared to the placebo group (5.2%), which was attributable to a slightly higher rate of cancer deaths in the aspirin group, a surprising finding which requires further research. Importantly, the aspirin-treated group also had a significantly higher rate of major bleeding including hemorrhagic stroke, bleeding in the brain, and gastrointestinal hemorrhage (3.8% compared to 2.7% in the placebo group).

As for the possible health benefits of a daily aspirin regimen, the study did not find any significant difference in cardiovascular health risks including coronary heart disease, heart attack, and ischemia. This suggests that, at least in healthy older adults, daily aspirin use does not have any clear health benefits and may in fact pose some health risks. It is important to note that the majority of the individuals in the trial did not take aspirin regularly before entering the study, so it is difficult to extrapolate this data to individuals who are already on an aspirin regimen. Importantly, the health benefits of aspirin for people who already have cardiovascular health conditions such as coronary artery disease or previous heart attack or stroke are clear and substantial. But for otherwise healthy older adults, beginning a daily aspirin routine may not be advisable without further research.

So where do we go from here in the search for age-delaying treatments? One of the largest advances in our understanding of small-molecule drugs which may improve human healthspan is the National Institute on Aging’s Interventions Testing Program (ITP). This program is an ongoing collaborative effort to test various treatments including nutrition, dietary supplements, pharmaceuticals, and other agents in mice to determine which have the potential to increase lifespan and delay or diminish age-related disease and dysfunction. Some of the treatments being tested include aspirin along with rapamycin, resveratrol, metformin, curcumin, and fish oil. We will dive into some of the most exciting results from these studies in future posts.

The fact is, it is often difficult to translate the discoveries at the bench to human treatments. We tend to lead more complex lives than laboratory animals (hopefully) and have more individual genetic variation compared to the genetically homogeneous animals used in laboratory experiments. It is challenging to develop well-controlled human trials, and if there is a possibility that one of the experimental treatments may cause harm or worsen underlying medical conditions, there are ethical issues to contend with as well. That is one of the main challenges facing our field and others that aim to improve human health and eliminate human disease.

The main point I would like to make here is that it can be enticing (and for companies, quite lucrative) to take results from mice or limited human trials and suggest that we’ve found a one-pill cure for aging. Or like in the case of aspirin, that a treatment that has a clear benefit for individuals with a specific health risk should therefore also be taken by healthy people to reduce their risk. In reality, it takes years of study and several well-designed experiments and trials before we can safely say that a given treatment is likely to have a health benefit and unlikely to cause any harm. We will continue to use this space as well as our social media pages to provide context for the most recent research out there so that you can stay informed and up to date on aging biology.