Decaffeinated coffee may be worse for drinkers' health than the caffeine-laden kind, scientists reported yesterday.

In the first randomised study of the two coffees, researchers found that the decaffeinated variety raises the level of fats and "bad" cholesterol in the blood more than caffeinated blends.

The finding was presented to a meeting of the American Heart Association after a study of 187 people by the Fuqua Heart Centre in Atlanta, Georgia.

Researchers found an 18 per cent rise in blood fat and an 8 per cent rise in a protein linked with LDL cholesterol among decaffeinated coffee drinkers compared with the those who drank caffeinated coffee or none at all.

Dr Robert Superko, who led the study, said decaffeinated coffee was less healthy because it is made from high-flavour beans that contain more oils. "The decaffeination process can extract flavenoids, so manufacturers tend to choose a bean that has a more robust flavour," he said.