Coffee, caffeine not tied to psoriasis

Boston - A new study suggests that coffee and caffeine are not associated with psoriasis incidence after adjustment for smoking.

Wenqing Li, Ph.D., of Brigham and Women’s Hospital and Harvard Medical School, and colleagues report in a research letter that they investigated the long-term association between coffee and caffeine intake and psoriasis in 82,539 women who were free from psoriasis in 1991. Participants completed questionnaires in 2005 to identify the incidence of psoriasis and were asked about food and beverage intake in 1991, 1995, 1999 and 2003.

HealthDay News reports that during 1,140,758 person-years of follow-up, the researchers identified 986 incident cases of psoriasis, and that in an age-adjusted model, the risk of psoriasis increased moderately as coffee consumption increased. The association was no longer significant after adjustment for smoking.

The association between decaffeinated coffee and the risk of psoriasis was not significant.

“We did not observe a material change of psoriasis incidence associated with coffee or caffeine intake, after adjusting for known confounders,” the authors wrote. “Smoking appears to be the major confounder underlying the observed significant association between coffee and caffeine intake and risk of psoriasis in age-adjusted models.”

The research letter appears in the March issue of the Archives of Dermatology.

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