Dietary patterns, nutrient intake and gastric cancer in a high-risk area of Italy

Objectives: To better understand the role of overall dietary patterns and m ajor energy-providing components in gastric cancer etiology. Methods: In a population-based case-control study conducted in a high-risk area in central Italy, 382 gastric cancer cases and 561 controls were avail able for analysis. Multivariate models based on energy-adjusted residuals a nd completely partitioned logistic models were used; dietary patterns were evaluated by factor analysis and multiple correspondence analysis. Results: Gastric cancer risk was inversely related to high energy-adjusted intakes of vegetable fat, sugar, beta-carotene, vitamin C, alpha-tocopherol , and nitrates. In contrast, significant positive associations emerged with high intake of protein, nitrite, and sodium. According to energy decomposi tion models, gastric cancer risk increased with increasing intake of protei n and decreased with increasing intake of sugar and total fat. The pattern analysis identified four dietary profiles, overall explaining 75% of total dietary variability. Two patterns, named "traditional" and "vitamin-rich", were strongly associated with gastric cancer risk and overall accounted for 44% of estimated gastric cancer attributable risk. The other two patterns, "refined" and "fat-rich", were not consistently associated with gastric ca ncer. Conclusion: Innovative methodological approaches may contribute to better e valuation of the complex relationship between diet and cancer risk and to p lanning dietary interventions.