Aspirin-related compounds have been used for the treatment of pain since the 16th century BC, when it was reported that people chewed on the bark of willow and papyrus.
He said low-dose aspirin can be recommended to people who have a history of heart attack or stroke.
This protective capacity of aspirin was extrapolated to people who were otherwise healthy to prevent a first heart attack or stroke, despite the evidence supporting this to be sparse.
The test subjects, majority from Australia, were older than 70, except for blacks and Hispanics in the United States, who were recruited at age 65 or older because people in those groups have a higher risk of heart disease and cardiovascular problems than whites.
Regardless, the findings raise serious questions as to whether otherwise healthy older people should routinely take low-dose aspirin.
However he added the findings didn't apply to people who have previously had a heart attack or stroke or had an existing condition such as angina.
Professor John McNeil, head of Monash University's Department of Epidemiology and Preventative Medicine, said the research sought to answer a question which has been "unresolved for a number of years".
Scientists looked at almost 20,000 healthy Australians and Americans aged over 70, and found taking low doses of aspirin for five years had no benefits - and it actually caused some harm.
"These initial findings will help to clarify the role of aspirin in disease prevention for older adults, but much more needs to be learned", Hadley said. The participants did not have cardiovascular disease, dementia or a physical disability. "So, this is a welcomed study, but everybody who is now taking aspirin should obviously see their GP before making changes to their regime", he told Sky News. Bleeding is a well-known side effect of aspirin, and is more common in older people. They were followed for an average of close to five years.
Significant bleeding-a known risk of regular aspirin use-was also measured. They were followed for a median of 4.7 years.
"Continuing follow-up of the ASPREE participants is crucial, particularly since longer term effects on risks for outcomes such as cancer and dementia may differ from those during the study to date", said Evan Hadley, M.D., director of NIA's Division of Geriatrics and Clinical Gerontology.
But the rate of major bleeding with daily aspirin use was 3.8 percent, versus 2.8 percent with placebo.
This study serves as a contradiction to previous belief that aspirin can decrease risk of death and risk of developing cardiovascular conditions.
Surprisingly, those who took daily aspirin also appeared to be more likely to die overall, apparently from an increased risk of succumbing to cancer. Numerous extra deaths were due to cancer, but Leslie Ford from the National Cancer Institute in Maryland said that until the team had analysed more data, the cancer findings "should be interpreted with caution".
Many healthyAmericans take a baby aspirin every day to reduce their risk of having a heart attack, getting cancer and even possibly dementia.
The study found the higher death rate in the aspirin-treated group was due primarily to a higher rate of cancer deaths.