Drinking decaffeinated coffee significantly increases an older woman’s risk of developing rheumatoid arthritis, while drinking tea appears to have the opposite effect, according to a recent study by researchers at the University of Alabama at Birmingham (UAB).

Posted on November 12, 2001 at 12:50 p.m.

BIRMINGHAM, AL — Drinking decaffeinated coffee significantly increases an older woman’s risk of developing rheumatoid arthritis, while drinking tea appears to have the opposite effect, according to a recent study by researchers at the University of Alabama at Birmingham (UAB). Dr. Ted Mikuls, lead investigator of the study, will present details of the findings during the American College of Rheumatology’s Annual Scientific Meeting, November 11-15, in San Francisco, California.

“We found that older women who drink four or more cups of decaffeinated coffee a day are more than twice as likely to develop rheumatoid arthritis as women who do not drink decaffeinated coffee,” says Mikuls, assistant professor of medicine with the Division of Clinical Immunology and Rheumatology at UAB. “In contrast, we found that women who drink more than three cups of tea a day are much less likely to develop the disease than those who don’t drink tea.”

Findings do not support an association between caffeine consumption and a reduced risk of rheumatoid arthritis. “Although we don’t know why decaffeinated coffee drinkers appear to be at increased risk, we speculate that it might be attributable to the preparation and processing of decaffeinated coffee,” says Mikuls. “Although also speculative, the reduced risk associated with drinking tea may be the result of tea’s anti-inflammatory and antioxidant properties.”

The study, conducted from 1986 to 1997, followed 31,336 women, ages 55 to 69, enrolled in the Iowa Women’s Health Study. Findings are based on data collected from four questionnaires completed by participants over the course of the study.

Rheumatoid arthritis, which affects 2.1 million Americans, primarily women, is an autoimmune disease in which the body’s immune system attacks healthy joint tissue causing inflammation and damage.

Musculoskeletal diseases, including rheumatoid arthritis, account for nearly $65 billion a year in medical care and other expenses, according to the Arthritis Foundation.

Given the economic health-related impact of rheumatoid arthritis and the global popularity of coffee and tea, results of the study may have important public health implications. “Further investigation is needed, but based on this study, drinking decaffeinated coffee and tea should be considered possible determinants of disease,” says Mikuls.”