Objectives: To better understand the role of overall dietary patterns and major 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 available for analysis. Multivariate models based on energy-adjusted residuals and 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 decomposition models, gastric cancer risk increased with increasing intake of protein 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 cancer.
Conclusion: Innovative methodological approaches may contribute to better evaluation of the complex relationship between diet and cancer risk and to planning dietary interventions.