Macronutrients, fatty acids, cholesterol and prostate cancer risk.

BACKGROUND The role of selected macronutrients, fatty acids and cholesterol in the etiology of prostate cancer was analyzed using data from a case-control study carried out in five Italian areas between 1991 and 2002. PATIENTS AND METHODS Cases were 1294 men with incident, histologically confirmed prostate cancer, and admitted to the major teaching and general hospitals of study areas. Controls were 1451 men admitted for acute, non-neoplastic conditions to the same hospital network. Information on dietary habits was elicited using a validated food frequency questionnaire including 78 food groups and recipes. Odds ratios (OR) and 95% confidence intervals (CI) were estimated for increasing levels of nutrient intake. RESULTS A direct association with prostate cancer was found for starch intake (OR = 1.4 in the highest versus the lowest quintile of intake; 95% CI: 1.1-1.8), whereas an inverse association emerged for polyunsaturated fatty acids (OR = 0.8; 95% CI: 0.6-1.0). Among polyunsaturated fatty acids, linolenic acid (OR = 0.7; 95% CI: 0.6-0.9) and linoleic acid (OR = 0.8; 95% CI: 0.6-1.0) were inversely related to prostate cancer. When the six major macronutrients were included in the same model, the adverse effect of high intake of starch and monounsaturated fatty acids was statistically significant together with the protective effect of polyunsaturated fatty acids. Results were consistent in separate strata of age, body mass index and family history of prostate cancer. CONCLUSIONS Starch and monounsaturated fatty acids were directly associated with prostate cancer risk and polyunsaturated fatty acids were inversely associated.