An aspirin a day may not keep the doctor away, new research suggests.
A low daily dose of the blood-thinning medicine has limited health benefits for older people hoping to prolong good health, a study involving more than 19,000 participants found.
Aspirin did not significantly reduce the risk of a heart attack, stroke, or extend life free of disability or dementia among healthy adults over the age of 70, a comprehensive study found.
However the medicine was linked with an increased risk of serious bleeding, in line with previous findings.
Lead researcher Professor John McNeil, of Monash University, Australia, said the findings show many older people may be taking the medicine “unnecessarily”.
He warned that the results do not apply to people with existing conditions such as a previous heart attack, angina or stroke, where aspirin is recommended to prevent further illness.
The results of the Aspirin in Reducing Events in the Elderly (ASPREE) trial have been published in three papers in the New England Journal of Medicine.
A total of 19,114 people, mostly over the age of 70, were enrolled in the study.
Around half were told to take a 100mg low dose of aspirin every day and the other group given a placebo, and followed up after around five years.
Treatment with aspirin did not affect survival free of dementia or disability, the study found, and rates of cardiovascular events, such as coronary heart disease, non-fatal heart attacks and strokes, were also similar to the placebo group.
Of the aspirin-takers, 3.8% experienced serious bleeding compared to 2.8% in the placebo group.
The aspirin group were also at a slightly increased risk of death.
Of those taking the medicine, 5.9% died during the study compared to 5.2% of the placebo group.
However the authors said the small increase in deaths, primarily from cancer, requires further investigation and may be coincidental.
Prof McNeil said: “Despite the fact that aspirin has been around for more than 100 years, we have not known whether healthy older people should take it as a preventive measure to keep them healthy for longer.
“Aspirin is the most widely used of all preventive drugs and an answer to this question is long overdue. ASPREE has provided this answer.”
He added: “It means millions of healthy older people around the world who are taking low dose aspirin without a medical reason, may be doing so unnecessarily, because the study showed no overall benefit to offset the risk of bleeding.”
The research was led by Monash University in Australia and the Berman Centre for Outcomes and Clinical Research in the US.