By Alison McCook
NEW YORK (Reuters Health) - Drinking multiple cups of coffee every day does not appear to increase your risk of developing rheumatoid arthritis (RA), new research suggests.
These findings appear on the heels of numerous other reports suggesting that the opposite was, in fact, the case.
After reviewing information collected from more than 80,000 women over an almost 20 year period, U.S. researchers found that the risk of RA appeared unrelated to the amount of decaffeinated coffee, coffee, tea and total caffeine women consumed.
However, a previous Finnish study found that people who drank at least 4 daily cups of coffee were more than twice as likely to develop RA, while another report showed that drinking multiple cups of tea each day could reduce that risk.
The author of the current report, Dr. Elizabeth W. Karlson, said that her study followed more people for more time than previous reports, and there is "very little biologic reason" why coffee or tea might influence the risk of RA.
"These findings should help settle the debate," she told Reuters Health.
RA is a chronic inflammatory condition in which the body's own immune system attacks the tissue lining the joints. The cause of RA is not well understood, but research suggests that age, smoking, obesity and genetic factors may play a role in the development of the disease.
During the current study, reported in the journal Arthritis & Rheumatism, Karlson and her team reviewed dietary information collected every 4 years between 1980 and 1998 from 83,124 women. Over the course of the study, 480 women developed RA.
Although women's choice of beverage appeared to have no influence on their risk of RA, their smoking habits did. Specifically, the researchers found that heavy smokers were more likely to develop RA than non-smokers, a finding that other researchers have discovered, as well.
Karlson, who is based at Brigham and Women's Hospital in Boston, said that coffee drinkers may be more likely to be long-term smokers than non-coffee drinkers, and this tendency may help explain why previous reports linked drinking coffee with RA.
SOURCE: Arthritis & Rheumatism, November 2003.