Taking aspirin every day ‘raises risk of internal bleeding by 30pc’

The findings add to evidence that, for healthy people, the dangers associated with aspirin can outweigh the benefits.

Aspirin, which thins the blood and prevents clotting, is a standard treatment for patients recovering from heart attacks or strokes.

Many doctors also prescribed regular aspirin on a precautionary basis to healthy people who may be at increased risk due to their medical and family history.

But long-term use of aspirin can lead to stomach ulcers and internal bleeding.

The new study, based on an analysis of data from nine clinical trials involving more than 100,000 participants, showed regular aspirin may cut cardiovascular disease events risk by 10 per cent.

However, this was largely due to a reduction in non-fatal heart attacks. The benefit was offset by a 30 per cent increase in the risk of life-threatening or debilitating internal bleeding events.

For every 120 people treated with aspirin for around six years, one cardiovascular event was averted. But over the same period, one in 73 people suffered from potentially significant bleeding.

Lead researcher Dr Rao Seshasai, from St George’s, University of London, said: “The beneficial effect of aspirin on preventing future cardiovascular disease events in people with established heart attacks or strokes is indisputable.

“We urge people with these conditions not to discontinue their medication unless advised to do so by their physicians.

“However, the benefits of aspirin in those individuals not known to have these conditions are far more modest than previously believed and, in fact, aspirin treatment may potentially result in considerable harm due to major bleeding.” The study also found “no evidence” that aspirin could prevent cancer deaths, despite the drug’s known anti-cancer properties.

Experts warned in 2009 that, for healthy people, daily doses of aspirin might potentially do more harm than good.

The advice was given by the Drugs and Therapeutics Bulletin (DTB) which concluded that routine use of aspirin could not be justified in “apparently healthy individuals” including those with raised blood pressure of diabetes.

The new research was published yesterday in the journal Archives of Internal Medicine.

Natasha Stewart, senior cardiac nurse at the British Heart Foundation, added: “People who don’t have symptomatic or diagnosed heart disease shouldn’t take aspirin.”