In recent years, epidemiological data has demonstrated that alcohol consumption is a risk factor for sunburn, melanoma and nonmelanoma skin cancer. We hypothesized that if the concentration of the antioxidants in the skin has already decreased due to alcohol consumption, then an adequate neutralization of the free radicals induced by ultraviolet light cannot be performed. Based on this hypothesis, we determined the carotenoid concentration in the skin and the minimal erythema dose (MED) of 6 male human volunteers before and after consumption of alcohol or alcohol and orange juice combined. The results showed a significant decrease in the carotenoid concentration in the skin and the MED after alcohol consumption, but no significant decrease after a combined intake of alcohol and orange juice.

Nutritional supplementation may provide a viable treatment alternative in patients with psoriasis. Randomized, controlled trials have shown the effectiveness of topical vitamin A and D derivatives, intravenousω-3 fatty acids, oral inositol, and various combined therapies. Dual therapies of ultraviolet B phototherapy and fish oil, retinoids and thiazolidinediones, and cyclosporine and a low-calorie diet were effective in the treatment of psoriasis in randomized, controlled trials. This contribution also reviews the potential negative effect of alcohol and the potential positive effects of vitamin B(12), selenium, retinoic acid metabolism-blocking agents, and a gluten-free diet in the treatment of psoriasis.