A new study suggests drinking four or more cups of coffee a day may actually lower incidence of gout, the most prevalent inflammatory arthritis in men age 40 or older.
But the study does not reveal any causal relationship between coffee drinking and risk of gout and the possibility can not be excluded that the association may possibly be due to a work of chance.
Gout is a painful condition that occurs when uric acid, a natural waste product formed in the body, is deposited as crystals in the joints and/or soft tissues, causing inflammatory arthritis, according to the National Institute of Arthritis and Musculoskeletal and Skin Diseases.
Coffee is one of the most popular beverages in the United States with more than 50 percent of Americans drinking two cups a day on average.
Early epidemiologic studies have linked coffee drinking with reduced risk of a number of health conditions from breast cancer to heart disease. Studies also show drinking coffee for a short term lowers insulin and uric acid, indicating that coffee may have any effect on the risk of gout.
In the current prospective study aimed at examining how coffee drinking affects gout, researchers at the University of British Columbia in Canada and colleagues from other medical organizations in the United States followed 45,869 men age 40 or older with no diagnosed gout when they were enrolled in the study in 1986.
Over 12 years of follow-up, Hyon K. Choi, MD, Dr. PH, and his associates surveyed the participants for their dietary habits through a food-frequency questionnaire every four years, including use of coffee, decaffeinated coffee, tea, and other caffeine-containing comestibles, such as cola and chocolate.
They recorded 757 cases of gout diagnosed in accordance with the American College of Rheumatology criteria.
Then the researchers analyzed the data to see if there is any correlation between coffee drinking and incidence of gout. The results reported in the June 2007 issue of Arthritis & Rheumatism showed coffee drinking was linked with lower incidence of gout.
Dr. Choi and colleagues found that the risk of developing gout decreased with increasing coffee consumption. Those who drank four to five cups a day were 40 percent less likely to develop gout than those who never drank coffee. The risk reduction seemed even more significant among those who drank six or more cups a day, the risk reduced by 59 percent.
In addition, drinking decaffeinated coffee was also associated with reduced risk of gout, indicating that caffeine is not the compound that is responsible for the association. Those who drank four or more cups of decaffeinated coffee were nearly 30 percent less likely to develop gout than those who did not drink any.
The total caffeine from all sources and tea intake were not linked with the risk of gout.
The researchers concluded that "these prospective data suggest that long-term coffee consumption is associated with a lower risk of incident gout."
"Is it possible those who had some conditions, even though they were not yet diagnosed at the time they entered the study, but they did not drink much coffee because their doctors advised them not to?" asked a scientist affiliated with foodconsumer.org who did not want to be named.
It is commonly believed that patients with gout should refrain from drinking coffee. If those who had some conditions and did not drink coffee because of their conditions were grouped into non-drinkers, this association would not be a surprise, he suggested.
But the possibility that drinking coffee lowers the risk of gout may not be excluded as evidence presented by the same authors in another report shows that drinking coffee, not drinking tea, reduced the serum level of uric acid, suggesting that drinking coffee may reduce risk of gout.
In addition, both studies suggested that some compounds other than caffeine in coffee may have a protective effect against gout.
The authors suspected chlorogenic acid, a strong antioxidant found in coffee, may be responsible for the possible protection of coffee against gout as it may improve insulin sensitivity, which in turn lowers the level of uric acid in the blood, potentially reducing the risk of gout.
The results of the current studies do not mean those who have gout should drink four or more cups of coffee a day to relieve their condition, the authors said. Further studies are needed.
Sources:
Article: "Coffee Consumption and Risk of Incident Gout in Men: A Prospective Study," Hyon K. Choi, Walter Willett, and Gary Curhan, Arthritis & Rheumatism, June 2007; (DOI: 10.1002/art.22712).
Article: "Coffee, Tea, and Caffeine Consumption and Serum Uric Acid Level: The Third National Health and Nutrition Examination Survey," Hyon K. Choi, Gary Curhan, Arthritis Care & Research, June 2007; 57:5; (DOI: 10.1002/art.22762).
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