A daily dose of aspirin can help prevent heart attacks in middle age people, say experts.
Heart attacks occur when a clot blocks a blood vessel, but aspirin makes it harder for blood clots to form.
An analysis led by researchers from Nottingham and Sheffield universities suggests that men from the age of 48, and women from 57 are likely to benefit from the drug.
The study involving almost 12,000 patients between 30 and 75 years of age showed that by the age of 47 in men and 58 in women, the 10-year coronary heart disease risk is ten per cent, which is worth treating.
At that point, unless someone is at risk of dangerous side effects because they have a condition such as a stomach ulcer, the benefits outweighed the disadvantages, they concluded.
However, according to researchers their findings did not apply to people with diabetes or those at high risk of bleeding,
They said that though diabetics were likely to benefit from aspirin treatment because of their high heart disease risk, the evidence was not yet quite clear.
They also suggested that, for anyone over the age of 75 years, the decision whether or not to take aspirin be made on an individual basis, as they were more likely to suffer bleeding complications.
Dr Iskandar Idris, lead researcher and honorary senior lecturer at Sheffield University, said that routinely prescribing aspirin in these age groups was a feasible option.
"The final decision about use of aspirin must eventually be made after discussion with a healthcare provider," the BBC quoted Idris as saying.
Dr Mike Knapton, director of prevention and care at the British Heart Foundation, said that robust research was needed before aspirin should be considered as a blanket primary prevention measure.
"We would encourage everyone to examine their own individual risk and take steps to reduce it by adjusting their lifestyle," he said.