The authors write:
Psoriasis is a common immune-mediated skin disease. The association between alcohol consumption and increased risk of psoriasis onset and psoriasis worsening has long been suspected. For example, individuals with psoriasis drink more alcohol than individuals without psoriasis, and alcohol intake may exacerbate psoriasis severity.
Alcohol consumption has been shown in previous studies to be linked to certain disease risk - e.g. the risk of gout is higher with beer consumption that wine or spirit consumption.
Abrar A. Qureshi, M.D., M.P.H., of Brigham and Women's Hospital and Harvard Medical School, Boston, examined data from 82,869 women between the ages of 27 and 44 years in 1991 to evaluate the link between different types of alcohol and psoriasis risk. The women, participants in the Nurses' Health Study II, reported the amount and type of alcohol they consumed on biennial questionnaires. The questionnaires also asked whether they had received a diagnosis of psoriasis.
By the end of 2005, 1,150 cases of psoriasis had developed - 1,069 of them were used for analysis.
The researchers found that women who consumed an average of at least 2.3 drinks per week had a 72% higher risk of developing psoriasis compared to women who did not consume alcohol.
When assessing the type of drink, there was a link between non-light beer and psoriasis. Women who consumed at least five beers per week were 1.8 times as likely to develop psoriasis compared to women who never consumed alcohol.
There was no increased risks of developing psoriasis among the regular light beer, red and white wine, and liquor (spirits) drinkers.
When only confirmed psoriasis cases - those in which women provided more details about their condition on a seven-item self-assessment - were considered, the risk for psoriasis was 2.3 times higher for women who drank five or more beers per week than women who did not drink beer.
The authors wrote:
Non-light beer was the only alcoholic beverage that increased the risk for psoriasis, suggesting that certain non-alcoholic components of beer, which are not found in wine or liquor, may play an important role in new-onset psoriasis. One of these components may be the starch source used in making beer. Beer is one of the few non-distilled alcoholic beverages that use a starch source for fermentation, which is commonly barley.
The authors noted that barley and other starches contain gluten, to which some psoriasis patients are sensitive. Light beer uses much less grain than normal or strong beers in its production, possibly explaining why there was no light-beer link to psoriasis risk.
The authors concluded:
"Women with a high risk of psoriasis may consider avoiding higher intake of non-light beer," the authors conclude. "We suggest conducting further investigations into the potential mechanisms of non-light beer inducing new-onset psoriasis.
Published online August 16, 2010. doi:10.1001/archdermatol.2010.204.
Written by Christian Nordqvist