The student was led by researched at Monash University and was publishes in the New England Journal of Medicine.
While a daily dose of the blood-thinning medicine can protect older people who have previously experienced heart attacks, strokes and angina, researchers found the drug did not extend the lifespan of healthy people over the age of 70.
The researchers did not state whether healthy older people who have been taking aspirin should stop. However, studies in younger people showed that the risks outweighed the benefits and the new research confirms that the same is true for the elderly.
The higher pace of cancer deaths became apparent three and a half years after the study began, particularly death from stomach and intestinal tumors.
Taking aspirin every day may cause pensioners more harm the good, a major new study has concluded. Most were aged 70 or older, but the ages of some of black and Hispanic participants living in the United States were as low as 65. All participants had to be free of dementia or a physical disability.
"If [a person has] been prescribed aspirin by their doctor they should assume there's a good reason". That compares with 90.5 percent of those taking a placebo.
Major hemorrhages were found to be more common in the aspirin group (8.6 versus 6.2 per 1,000 person-years, HR 1.38, 95% CI 1.18-1.62).
But the trial found no benefit for healthy people over the age of 70, and the pills increased the risk of potentially fatal internal bleeding. Hemorrhagic stroke, bleeding in the brain, gastrointestinal hemorrhages or hemorrhages at other sites that required transfusion or hospitalization occurred in 361 people on aspirin and in 265 taking the placebo.
"After a median of 4.7 years of follow-up, the rate of cardiovascular disease was 10.7 events per 1000 person years in the aspirin group and 11.3 events per 1000 person years in the placebo group".
However the authors said the small increase in deaths, primarily from cancer, requires further investigation and may be coincidental.
"ASPREE is a study that was probably long overdue", he said. "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 remains a relatively safe medication, but more research was needed to investigate the longer-term benefits and risks of its daily use", he said, adding that researchers were following the health of participants to determine if benefits, including cancer prevention, emerge from taking the drug over a period of time.
'Analysis of all the cancer-related data from the trial is under way and until we have additional data, these findings should be interpreted with caution'.
"These findings will help inform prescribing doctors who have always been uncertain about whether to recommend aspirin to healthy patients who do not have a clear medical reason for doing so", John McNeil, head of the Department of Epidemiology and Preventive Medicine at Monash University in Australia, said in a statement.