Finnish study links coffee to rheumatoid arthritis
New research carried out in Finland has linked drinking coffee to rheumatoid arthritis.
The study reports in the journal Annals of the Rheumatic Diseases, that people who drink more than four cups of coffee a day could be putting themselves at increased risk of developing the condition.
The researchers at the claim to have shown a link between the number of cups of coffee drunk each day, and the chances of developing rheumatoid factor - a hallmark antibody of rheumatoid arthritis which shows up before any symptoms develop, and is a predictor of rheumatoid arthritis.
But the Arthritis Research Campaign said that although the work was interesting, it was too simplistic and should not stop people drinking coffee.
"Drinking a lot of coffee does not mean you are going to develop rheumatoid arthritis - there are many other factors to take into account," said a spokeswoman. "When you consider that rheumatoid arthritis is a complex disease with a large genetic element, and that environmental and genetic factors interact to play a part in its development, to link the disease with coffee consumption is rather simplistic."
Two large studies were carried out in Finns over the age of 30 by the National Public Health Institute in Helsinki. One was a cross-sectional survey of almost 7,000 people, and the other involved almost 19,000 people who were monitored for 15 years.
Both showed that those who drank more coffee were likely to develop rheumatoid factor than those who didn't. The researchers said that there was known to be a link between smoking and obesity and rheumatoid arthritis, but even after they weighted their findings to remove those factors - the association between coffee drinking and RA remained.
"It cannot be concluded whether the associations between coffee consumption and rheumatoid factor were due to coffee exposure, or to some lifestyle of dietary factors closely linked with it," they added.
"That our main results, from two independent studies with different designs and outcomes, points to the same inference, clearly suggests that the phenomenon is real, even if its mechanism remains unknown."
Research at the ARC Epidemiology Unit at the University of Manchester, has shown that there may be associations between smoking, blood transfusions and obesity with rheumatoid arthritis.
