TUESDAY, Aug. 17 (HealthDay News) -- Women who drink regular beer may be increasing their risk of developing psoriasis, an autoimmune disorder affecting the skin, new findings suggest.
Other options, such as light beer and wine, were not linked to such a risk.
Researchers from Brigham and Women's Hospital, Harvard Medical School, and Boston University tracked 82,869 women who had not initially been diagnosed with psoriasis for about 15 years, from 1991 through 2005. The participants, from the Nurses' Health Study II, reported their own alcohol consumption and also, over the course of the study, reported whether a doctor had diagnosed psoriasis.
The researchers found that even relatively moderate amounts of beer seemed to increase the risk of psoriasis, with 2.3 drinks a week driving up the risk almost 80 percent.
And five beers a week more than doubled the risk of being diagnosed with this skin condition, as compared with teetotalers.
"We can say that if a woman would like to consume alcohol and if she has a family history of psoriasis or known psoriasis in the past or some other reason she might be predisposed to psoriasis, the alcohol of choice probably should not be nonlight beer," said Dr. Abrar A. Qureshi, lead author of the article appearing in the December issue of Archives of Dermatology.
But Bruce Bebo, director of research and medical programs at the National Psoriasis Foundation, feels the findings "need more investigation to determine whether there's a real connection or not."
And on the question of drinking in general, he added, "from the point of view of the health-care provider, trying to limit alcohol consumption for lots of reasons is important. If this encourages people to limit alcohol consumption, I think that's a positive outcome, but I don't think the National Psoriasis Foundation or any physician group would make a recommendation."
Previous studies have found an association between alcohol and psoriasis, although the reasons for this link were not clear.
"There is evidence that alcohol consumption can affect immune responses and psoriasis is an autoimmune disease," Bebo said. "There's also some evidence that it can affect the biology of [the skin cells known as] keratinocytes. But ... then why would it be nonlight beer, why not wine or other alcohol? Maybe there's something in wine that ... might reverse the effect."
"When we looked up the components of different alcoholic beverages, one thing that stood out for nonlight beer was the amount of protein, gluten in particular," said Qureshi, who is an assistant professor of dermatology at Brigham and Women's Hospital and Harvard Medical School in Boston. "When we stumbled on this, we realized that there have been reports in the past that ingested gluten was associated not just with psoriasis worsening but other autoimmune diseases, such as celiac disease."
Another study in the same issue of journal found that psoriasis carries a heavy mental health burden, with people who have the disease suffering higher rates of depression, anxiety and even suicidality.
The link was more pronounced in men, according to the researchers from the University of Pennsylvania in Philadelphia.
A third study in the journal reported that treating psoriasis with narrow-band UV-B light rays may increase vitamin D levels in patients and help reduce the burden of the disease.
But the Irish authors, who reported various financial ties with pharmaceutical companies, don't believe that the higher vitamin D levels actually were responsible for the psoriasis clearing.
The National Psoriasis Foundation has more on this condition.