Researchers from the U.S. and Australia are joining efforts to increase the length of disability-free life of older adults, in the biggest international trial ever, called the Aspirin in Reducing Events in the Elderly (ASPREE) which is sponsored by the US National Institute on Aging (NIA).

It has been known for some time that aspirin helps prevent heart attacks and strokes in people with heart disease. While the benefits do outweigh risks connected with aspirin - for example, bleeding - the function of aspirin in people without cardiovascular diseases is not clear.

The aim of the ASPRE study is to assess whether aspirin can not only increase life span, but boost a life free of physical disability and dementia among healthy older people.

Dr Anne Murray, investigator for ASPREE who is also an epidemiologist and geriatrician, and associate professor of medicine and geriatrics at the University of Minnesota believes that aspirin has the potential ability to prolong life free of disabilities and memory problems as it is widely available and cheap.

Currently, the overall information about the effects of aspirin in older adult population is still limited as the previous trials only focused on middle-aged people. The potential benefits of low dose aspirin and whether they outweigh the risks particularly for people aged 70 and older, will be for the first time, assessed in the ASPREE study.

Professor John McNeil, Head of the Monash School of Public Health and Preventative Medicine in Australia, who is also ASPREE's principal investigator said over the years, doubts had been raised about the evidence of the benefits of aspirin in healthy people and further studies have been called for.

Because of its proven effectiveness in preventing second events, many doctors have also prescribed aspirin to prevent heart attacks and strokes in otherwise healthy people.

However, in the last couple of years, serious doubts have been raised about the evidence supporting this practice, and as a result, editorials in major medical journals have call for this question to be settled, said Prof McNeil.

The study will be participated by 6,500 healthy individuals age 70 and over in the US, and 12,500 in Australia. The subjects will be randomly assigned to take either low-dose aspirin or placebo daily for five years.