Older women who drink four or more cups of decaffeinated coffee a day are more than twice as likely to develop rheumatoid arthritis (RA) than regular coffee drinkers, according to research presented recently at an American College of Rheumatology meeting.

Dr Ted Mikuls, assistant professor at the University of Alabama-Birmingham, led the 11-year study into the link between 'decaff' and RA, following the consumption habits and health of 32,000 woman aged between 55 and 69 in the Iowa area.

He concluded: "Women who drank regular coffee did not have the increased risk of RA - so it seems as if there is something about the decaffeinated coffee that is increasing the risks."

Mikuls believes that the increased risk could be caused by the preparation and processing of decaffeinated coffee, which has involved strong chemical solvents. The majority of coffee makers today do employ other safer methods to decaffeinate coffee however, he stressed.

This is the first study of its kind to link the painful auto-immune disorder and decaffeinated coffee, but Mikuls stresses that there is no cause for alarm, and that as yet the link is only an "association". "There is a long way to go before it becomes a positive link," he added.