Daily aspirin can be risky

LONDON - An aspirin a day - regarded for at least 20 years as one of the simplest and most effective ways of preventing heart attacks and strokes - may do more harm than good.

Scientists have discovered that the common painkiller, taken by millions worldwide to thin the blood and ease strain on the heart, increases the risk of bleeding, which in some patients outweighs the benefits.

Researchers at the Wolfson Institute of Preventive Medicine in London studied for seven years 5000 men aged 45 to 69 who were at higher risk of heart disease, but who had not had a heart attack. The men were divided into four groups to accurately establish the effects of aspirin.

The results, published in the British Medical Journal, showed that aspirin reduced the risk of a heart attack in men with low blood pressure by about 45 per cent but not in those with high blood pressure (above 145mm of mercury).

However, aspirin is a stomach irritant and is known to increase the risk of bleeding, mainly in the gastrointestinal tract, which outweighed the benefit in men with higher blood pressure. Even in men with low blood pressure, the benefit did not clearly outweigh the risk.

In one study they cited, a low daily dose of aspirin more than doubled the risk of bleeding from stomach ulcers.

Professor Tom Meade, director of the Medical Research Council Epidemiology and Medical Care Unit at the Wolfson Institute, said the findings only applied to people taking aspirin to prevent heart trouble but who had never had a heart attack or stroke.

"It is very important that people who have already had a heart attack or stroke who are on aspirin should continue taking it, because for them the risk of another heart attack or stroke is very high.

"Taking a daily aspirin will lower their risk by a great deal more than it will increase the risk of bleeding."

However, there were "at least tens of thousands" of people in Britain taking aspirin as a preventive measure - although they had never had heart trouble - because they had a history of heart disease in their families or high cholesterol. Those with high blood pressure were at greatest risk because both high blood pressure and aspirin increased the risk of bleeding into the brain.

Professor Meade said: "Bleeding can be a serious matter with about 10 per cent of cases, mainly among the elderly, being fatal."

The study is the first to show clearly that the harm caused by aspirin in otherwise healthy men may outweigh the benefit. An American study 12 years ago had a similar finding, but the results were not significant.

Professor Meade said the results needed confirmation by other studies.

He said that the protective effect of aspirin was so well established in people who had already had a heart attack that no one had thought to examine whether the same applied to people who had not had a heart attack.

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