According to a large clinical trial published online in September 2018 in The New England Journal of Medicine, taking a low-dose aspirin did not prolong life in healthy, elderly people and increased the risk of developing hemorrhages, the release of blood — either inside or outside the body — from broken blood vessels.
The ASPirin in Reducing Events in the Elderly (ASPREE) trial, which began in 2010, studied 19,114 older people (16,703 in Australia and 2,411 in the United States).
Participants had to be 70 years old or older, unless they were African-American or Hispanic and living in the US, in which case the minimum age of participation was 65 because of those groups' increased risks for dementia and cardiovascular disease.
"At study enrollment, participants could not have dementia or a physical disability and had to be free of medical conditions requiring aspirin use. They were followed for an average of 4.7 years to determine outcomes," a September 2018 press release states. The study was led by John J. McNeil, head of the Department of Epidemiology and Preventive Health at Monash University, and Anne M. Murray, director of the Berman Center for Outcomes and Clinical Research at Hennepin Healthcare in Minneapolis.
The findings revealed that 90.3 percent of participants who were treated with 100 milligrams of low-dose aspirin every day were still alive at the end of treatment without "persistent physical or dementia, compared with 90.5 percent of those taking a placebo," the press release states.
In addition, 5.9 percent of participants taking aspirin had an increased risk of death compared to 5.2 percent taking a placebo.
"This effect of aspirin has not been noted in previous studies; and caution is needed in interpreting this finding. The higher death rate in the aspirin-treated group was due primarily to a higher rate of cancer deaths. A small increase in new cancer cases was reported in the group taking aspirin, but the difference could have been due to chance," the press releases notes.
The researchers also found that incidences of major cardiovascular events such as coronary heart disease, nonfatal heart attacks and fatal and nonfatal ischemic strokes were similar among those taking aspirin and a placebo, with 448 people taking aspirin experiencing a cardiovascular event, compared with 474 people taking a placebo.
However, participants taking low-dose aspirin daily were more likely to have bleeding in the gastrointestinal tract and brain.
"Clinically significant bleeding — hemorrhagic stroke, bleeding in the brain, gastrointestinal hemorrhages or hemorrhages at other sites that required transfusion or hospitalization — occurred in 361 people (3.8 percent) on aspirin and in 265 (2.7 percent) taking the placebo," the release explains.
According to the American College of Cardiology, only high-risk patients should take low-dose aspirin to prevent a cardiovascular event at the advice of their own physicians. The study also notes that the study's findings do not apply to people "with a proven indication for aspirin such as stroke, heart attack or other cardiovascular disease." In addition, the study did not evaluate the effect of daily low-dose aspirin on people younger than 65.
"Also, since only 11 percent of participants had regularly taken low-dose aspirin prior to entering the study, the implications of ASPREE's findings need further investigation to determine whether healthy older people who have been regularly using aspirin for disease prevention should continue or discontinue use," the press release notes, quoting Evan Hadley, director of the National Institute of Aging Division of Geriatrics and Clinical Gerontology.