Caffeine & Coffee / Decaf Coffee Increases Rheumatoid Arthritis Risk

Decaffeinated coffee consumption is an important yet modifiable risk factor in the development of rheumatoid arthritis. Given the global popularity of coffee, the findings have potential public health implications.

The researchers followed more than 31,000 women aged 55 to 69 included in the Iowa Women's Health Study from 1986 through 1997. They tracked the 158 women who developed rheumatoid arthritis during that time period and compared them with women who did not develop the disease.

In rheumatoid arthritis, the immune system attacks the lining of the joints, causing pain, stiffness and inflammation.

Women drinking four or more cups a day of decaffeinated coffee were at more than twice the risk of developing rheumatoid arthritis.

However, women drinking regular coffee were not at increased risk, while those drinking more than three cups of tea had a 60% reduced risk of developing the disease.

They found no association with daily caffeine intake or caffeinated coffee use and the risk of developing rheumatoid arthritis. The researchers took into account other possible contributing factors, such as age, smoking history, marital status and the use of hormone replacement therapy. The association persisted even after accounting for other factors that may be associated with rheumatoid arthritis.

In a similar study, researchers evaluated risk factors for developing rheumatoid arthritis among 64,000 black women followed since 1995 as part of the Black Women's Health Study.

The researchers reported that drinking more than one cup a day of decaffeinated coffee seemed to quadruple the risk of developing rheumatoid arthritis.

As far as the researchers knew, these were the first observations of decaffeinated coffee having an association with any metabolic disorder. They speculated that the use of industrial solvents in the decaffeination process may play a role. There is accumulating evidence that environmental factors play an important role in the development of rheumatoid arthritis.

American College of Rheumatology's annual meeting San Francisco November 13, 2001