Health experts are divided over whether all people over 50 should be given daily doses of aspirin to protect their heart's health.
The drug can cut the risk of heart attacks or strokes, but there are concerns it can increase some people's risk of experiencing bleeding in the brain or stomach.
Experts outline their opposing viewpoints in the latest issue of the British Medical Journal.
FOR - DR PETER ELWOOD AND COLLEAGUES, CARDIFF UNIVERSITY
Aspirin is more likely to do good than cause harm, Dr Peter Elwood and colleagues say in the BMJ.
"At a low dose, undesirable effects are unusual and seldom serious, and probably 90 to 95% of the population could take low dose aspirin without problems."
They add: "Each person, not a doctor should evaluate risks and benefits.
"A heart attack or stroke has serious physical and medical effects on the family, work colleagues and friends.
"Most older people know this from experience and many will dread a vascular event [a stroke or heart attack].
"They are likely to accept a small increased risk of a bleed or other side-effect in exchange for a reduced risk of a heart attack or stroke."
They add that there is growing evidence to suggest regular aspirin may reduce cancer and dementia as well.
"Within the UK, population screening to identify and treat those at high risk does not seem to be successful in controlling vascular disease.
"Many people at high risk remain undetected.
"Health promotion initiatives seem to achieve little behavioural change in the general community and, without additional social support, health education seems effective only in higher social classes.
"The possibility that a simple, daily, inexpensive low-dose pill would achieve a reduction in vascular disease events, and may achieve reductions in cancer and dementia, without the need for screening, deserves serious consideration."
AGAINST - DR COLIN BAIGNET, OXFORD RADCLIFFE INFIRMARY
The benefits of taking aspirin certainly do outweigh the risks for people already known to be at a high risk of heart disease or stroke, according to Dr Colin Baignet.
But in the BMJ, he adds: "Unfortunately, predicting the benefits and hazards of aspirin in someone without known disease is far less straightforward."
And he said studies had suggested that for people aged 50 to 60, the risk of a cardiovascular problem was lower than that of a bleed in the stomach.
"Given the lack of a clear benefit at 60 , we might consider raising the age limit to 65 or 70.
"But, whereas the benefits of aspirin on myocardial infarction (heart attack) are reasonably well defined in middle age, little is known of its effects in older people.
"Given that the observational studies strongly suggest that the risks of bleeding might increase substantially in older people, as does fatality from a bleed, we need decisive evidence of benefit in this age group before exposing large numbers of healthy people to potential harm.
"We should not contemplate an age threshold approach to primary prevention with aspirin until we have much better evidence of its benefits in older people."