Coffee not linked to psoriasis

First it was beer, then it was cigarettes. Finally, researchers have found a vice that's not tied to psoriasis: coffee.

In fact, when Dr. Abrar Qureshi and his team at Brigham and Women's Hospital in Boston first set out to study whether there was a link between the skin disease and java, they thought the anti-inflammatory properties of caffeine might actually protect against psoriasis.

That had been reported by a group of Irani researchers, who applied caffeine directly to the skin of volunteers with psoriasis and found an apparent benefit.

Scientists believe psoriasis is caused by an abnormal immune system attack on the body's own cells, which causes them to form red, scaly patches all over the body that usually itch.

Typical treatments for psoriasis include topical creams, ultraviolet light exposure and systemic drugs that target the immune system.

To see whether consumed caffeine had any influence on whether a person developed psoriasis, Qureshi and his colleagues looked at more than 82,000 participants in the Nurses' Health Study.

All of the participants had filled out questionnaires about their daily food and beverage intake in 1991 and were free of psoriasis at that point.

Coffee may improve psoriasis treatment response Patients with psoriasis who drink coffee frequently respond better to treatment with methotrexate and sulfasalazine, Dr. Yolanda Helfrich reported at the annual meeting of the Society for Investigative Dermatology.

That should be good news for patients who like to drink coffee, said Dr. Helfrich of the department of dermatology, University of Michigan, Ann Arbor.

The impact of coffee and other caffeine-containing beverages on inflammatory conditions such as psoriasis has been the subject of controversy for some time. Many people consider caffeine to be proinflammatory and have suggested that patients with inflammatory diseases cut their consumption.

On face value, one would expect coffee to thwart the efficacy of drugs such as methotrexate (MTX) and sulfasalazine (SSZ). "Both of these drugs are anti-inflammatory, and they work by inhibiting an enzyme called 5-amidoimidazole-4-carboxamide ribonucleotide (AICAR) transformylase, resulting in AICAR accumulation. This leads to increased adenosine which has anti-inflammatory properties," explained Dr. Helfrich. "Caffeine acts as an adenosine receptor antagonist, so you'd expect it to inhibit MTX and SSZ."

Over the next 14 years, nearly 1,000 people in the study developed psoriasis, the team reports in the Archives of Dermatology.

Initially, the risk did seem a bit higher among those who got a lot of caffeine in their diet, whether from coffee, tea, soft drinks or chocolate.

Warning Alcohol, coffee, certain sauces (especially spicy ones), tomato juice and canola or vegetable oil can trigger episodes of psoriasis in certain people, so it is important to pay attention after consuming these foods to see the effect they cause to the body. Spices can also be damaging to the body, especially the hot ones or the ones based on nuts or citrus. Examples include pepper, hot sauce, gravies, vinegar, cumin, mustard and curry.