Decaf coffee associated with Rheumatoid Arthritis

Decaf coffee associated with increased risk of rheumatoid arthritis

Last Updated: 2002-02-08 13:55:37 EST (Reuters Health)

NEW YORK (Reuters Health) - Drinking more than three cups of decaffeinated coffee per day appears to increase the risk of developing rheumatoid arthritis, based on results of a prospective study of a cohort of older women. In contrast, tea drinking may reduce the risk, while consumption of caffeinated coffee seems to have no effect.

As part of the Iowa Women's Health Study, more than 30,000 women ages 53 to 69 were questioned in 1986 regarding average intake of the beverages over the previous year. Between 1986 and 1997, there were 8 validated incident cases of rheumatoid arthritis within the cohort.

Dr. Kenneth G. Saag, of the University of Alabama at Birmingham, and colleagues estimated relative risks for rheumatoid arthritis after adjusting for age, marital status, smoking history, alcohol use, age at menopause, and use of hormone replacement therapy. Their findings appear in the January issue of Arthritis and Rheumatism

The relative risk associated with regular coffee intake of at least four cups per day was 0.98 compared with those drinking none, while for the highest category of caffeine intake, > 376.5 mg/day, the relative risk was 0.94.

For the same amount of decaffeinated coffee consumption, the relative risk was 2.44 (p = 0.003). However, there did not appear to be a dose response, because the relative risk associated with less coffee was no more than 1.11.

For more than three cups of tea per day, the relative risk was 0.35. However, this finding was not statistically significant (p = 0.33) because only five women reported this amount of tea consumption. Dr. Saag's team suggests that the link with decaffeinated coffee may be related to the direct application of industrial solvents to coffee beans, the method used to extract caffeine prior to the mid-1970s. Tea's apparent protective effect could be due to its antiinflammatory and antioxidant properties, they add.

Arthritis Rheum 2002;46:83-91.