李宜昌YI-CHANG LIVO NHAT KHOA醫療產業科技管理學系越南境外碩士專班2026-10-152026-01-1220262025-11-06https://handle.ncl.edu.tw/11296/uf92j2https://scholars.csmu.edu.tw/handle/123456789/22025Background: Gastrointestinal (GI) cancers remain a major global health burden, and dietary factors play a pivotal role in their pathogenesis. The Dietary Inflammatory Index (DII) and the Dietary Oxidative Balance Score (DOBS) are composite indicators quantifying the inflammatory and oxidative properties of diet. However, their combined impact on GI cancer risk has not been fully elucidated.Methods: This cross-sectional analytical study used pooled data from 22,328 adults aged ≥18 years participating in the U.S. National Health and Nutrition Examination Survey (NHANES) 2013–2023 cycles. Dietary information from 24-hour recalls was applied to calculate DII and DOBS scores. GI cancer status was identified from self-reported physician diagnoses. Survey-weighted logistic regression models were conducted to evaluate the independent and combined associations of DII and DOBS with GI cancer risk, adjusting for demographic, lifestyle, and clinical covariates. Statistical analyses were performed using R software version 4.5.0.Results: The weighted prevalence of GI cancer was 0.66% (95% CI: 0.54–0.81). Participants with GI cancer were older and had higher rates of comorbidities, alongside lower intakes of protein, fiber, omega-3 fatty acids, and antioxidant micronutrients (all p < 0.05). Higher DII values were significantly associated with increased GI cancer risk (adjusted OR = 1.34, 95% CI: 1.12–1.60), while higher DOBS values were inversely associated (adjusted OR = 0.78, 95% CI: 0.65–0.92). The combined high-DII/low-DOBS dietary profile conferred the greatest risk, with an odds ratio exceeding 2.0 compared to the low-DII/high-DOBS reference group (p < 0.001).Conclusions: Pro-inflammatory and pro-oxidative dietary patterns are independently and synergistically associated with higher risks of gastrointestinal cancers among U.S. adults. Diets characterized by low DII and high DOBS—rich in anti-inflammatory and antioxidant nutrients—may offer substantial protective effects. These findings emphasize the importance of integrative dietary strategies targeting both inflammation and oxidative stress for GI cancer prevention..飲食發炎指數胃腸道癌症氧化平衡評分Dietary Inflammatory Index (DII)gastrointestinal cancersOxidative Balance Scorethesis