Researchers dispute belief that aspirin prevents blood clots

New Zealand medical researchers are disputing the long-held belief that aspirin wards off deep vein thrombosis in long-distance air travellers.

Their research showed some of the 1000 long-distance travellers studied who took aspirin still developed blood clots.

The Medical Reseach Institute said aspirin was not treating the condition and could cause serious side-effects, such as triggering asthma attacks and aggravating digestive conditions.

About 20 per cent of asthmatics were sensitive to salicylate, the main compound in aspirin.