A population-based case-control study of diet and melanoma risk in northern Italy

Objective: We aimed at examining the association between dietary constituents and risk of cutaneous melanoma. Design: In an area of northern Italy we recruited 59 newly diagnosed melanoma patients and 59 age- and sex-matched population controls, to whom we administered a validated semi-quantitative food-frequency questionnaire. Results: We found an excess risk of melanoma in subjects with a higher energy-adjusted intake of total polyunsaturated fatty acids and, in particular, of linoleic acid (relative risk=2.16 for intake in the highest tertile compared with the lowest tertile, P for linear trend=0.061). Conversely, disease risk was inversely associated with the consumption of soluble carbohydrates (relative risk=0.34 for intake in the upper vs. the lowest tertile adjusting for total energy intake, P for linear trend=0.046). No other dietary factors, including alcohol, vitamins and trace elements, correlated with melanoma risk. The association of melanoma risk with linoleic acid and soluble carbohydrates intakes was further strengthened in multivariate analysis, and when analysis was limited to females. Conclusions: Overall, these results indicate that an excess energy-adjusted intake of linoleic acid and a lower consumption of soluble carbohydrates may increase melanoma risk.