Prof Peter Rothwell of Oxford University has found that taking the painkiller daily for five years can reduce the chance of developing colorectal cancer by a quarter and cut deaths from the disease by a third.
He said these results are the 'tip of the iceberg' and are likely to be an underestimate of its benefit in colorectal cancer prevention.
n addition he believes a similar effect is likely in other cancers such as breast, ovarian, womb, stomach and small bowel.
Prof Rothwell who is 46 said he and his wife both started taking low-dose aspirin themselves in order to reduce the chance of cancer several years ago and others in their 40s and 50s should consider it.
"The whole approach to aspirin is likely to change over the next few years. Currently people take it to prevent vascular events (such as heart attacks and stroke) but it is likely that in five years people will be taking it to prevent non-vascular diseases like cancer as well."
The drug, which is over 110 years old, was originally formulated as a painkiller but researchers are increasingly finding new benefits for it in diseases ranging from heart disease to dementia.
Prof Rothwell examined trials in which people took 75mg of aspirin a day for an average of five years and followed them up for 20 years.
The findings are published in The Lancet medical journal.
This is a lower dose than when used as a painkiller and costs the NHS just three pence per patient per day.
Colorectal cancer is the third most common cancer in Britain with around 39,000 people diagnosed each year and around 16,000 die annually.
Prof Rothwell, of the John Radcliffe Hospital and Oxford University, said the trials looked at the benefits of taking aspirin for five years but he suspects the effect of taking it for longer would 'undoubtably be much larger'.
He said as colorectal cancers start to appear in the people aged 55 and older and take around ten years to develop, the ideal time to start taking aspirin would be in the 40s and continue with it until around the age of 75 when the side effects of aspirin start to outweigh the benefits. The effect of taking aspirin may continue for around ten years after stopping it, he said.
The major side effect of aspirin is internal bleeding because it can disturb the lining of the stomach but this is reduced at lower doses.
The Department of Health has announced that pilots of a new colorectal screening programme will start next year in people using a scope to look for changes in the bowel that could signal cancer.
Prof Rothwell said use of aspirin would dovetail perfectly with the new programme as the drug prevents more cancers at the top of the bowel which will not be detected by the screening test.
There was a 70 per cent reduction in cancers and deaths from cancers in the upper colon among those taking aspirin for five years, the analysis found.
Aspirin blocks the effects of substance called cyclo-oxygenase and is produced by some forms of cancer which is why Prof Rothwell believes other cancers will respond to aspirin.
Other experts have now called for guidelines to be drawn up on how aspirin should be used to prevent cancer.
Dr Robert Benamouzig and Dr Bernard Uzzan, of the Avicenne Hospital, in Bobigny, France, wrote in an accompanying editorial: “This interesting study could incite clinicians to turn to primary prevention of colorectal cancer by aspirin at least in high risk-populations. Specific guidelines for aspirin chemoprevention would be the next logical step."
Mark Flannagan, Chief Executive of Beating Bowel Cancer said: “These are very positive results. This was a big study over a long period of time and reinforces the message that aspirin may be important in significantly reducing the number of cases and deaths from bowel cancer.
"The results suggest that taking aspirin in conjunction with a healthy diet and lifestyle might reduce your risk of developing bowel cancer. However, anyone considering starting a course of medication should first consult their GP.
“As Professor Rothwell suggests, a low dose of aspirin may fit well with the flexible sigmoidoscopy screening programme that will be launched by the Government next year. We will have to see how these results might be considered during the roll out of flexible sigmoidoscopy.”