Dietary factors and the risk of psoriasis. Results of an Italian case-control study

Summary We have conducted a case‐control study to explore the relation between the consumption of selected foods and psoriasis. The out‐patient services of nine teaching hospitals and five general hospitals in northern and southern Italy took part. Cases were newly diagnosed psoriatics with a history of skin problems of no more than 2 years. As controls. we selected subjects with newly diagnosed skin conditions, other than psoriasis, who were seen in the same out‐patient clinics. Inclusion of cases and controls was limited to the age group 16–65 years. A total of 316 psoriatics and 366 controls were recruited. Anthropomentric measures, including height and weight, were obtained. Diet was assessed by a semiquantitative food frequency questionnaire. Psoriasis appeared to be positively associated with body mass index (X21 trend 4.3, P < 0.05). Significant inverse relations with psoriasis were also observed for the intake of carrots (X21 trend 4.8, P < 0.05), tomatoes (X21 trend 26.3, P < 0.01), fresh fruit (X21 trend 11.7, P < 0.01) and index of beta‐carotene intake (X21 trend 9.1, P < 0.01). Although largely explorative, these results provide some evidence for a potential role of diet in psoriasis.