Dietary carotenoids and vitamin A are associated with lower gastric cancer risk and favorable inflammatory and oxidative stress biomarkers: an incident case- control study.

BACKGROUND: Dietary carotenoids and vitamin A may contribute to gastric cancer (GC) prevention through anti-inflammatory and antioxidant mechanisms; however, epidemiological evidence remains limited. We investigated the associations of total and individual carotenoid and vitamin A intakes with GC and their relationships with inflammatory/oxidative stress biomarkers. METHODS: The case-control study included 177 adults (82 GC incidence cases/95 controls). A validated 168-item food frequency questionnaire assessed dietary intakes of individual carotenoids and preformed vitamin A. Metabolic biomarkers, lipid profile, inflammatory/oxidative stress markers [e.g., high-sensitivity C-reactive protein (hs-CRP), tumor necrosis factor-alpha (TNF-α), interleukins (6/1β/10/4), total antioxidant capacity (TAC), and malondialdehyde (MDA)] were measured. Multivariable logistic regression models estimated odds ratios (ORs) for GC risk; linear regression models examined associations between carotenoid intakes and biomarkers. RESULTS: Total carotenoid (mg/d; OR: 0.86, 95%CI: 0.81-0.98), β-carotene (mg/d; OR: 0.77, 95%CI: 0.65-0.90) and vitamin A (mg RAE/d; OR: 0.29, 95%CI: 0.09-0.95) intakes, as continuous variables, and also as binary variables (based on the median cut-offs), in all models (also adjusted for age, sex, smoking, education, marital status, physical activity, cancer history, H. pylori, NSAIDs intake, body mass index, total energy intake), were inversely associated with GC odds. In fully adjusted models, higher total carotenoid intake (mg/d) was associated with lower LDL-c (β: -1.60, 95%CI: -2.91, -0.25) and IL-6 (β: -7.92, 95%CI: -14.00, -2.00); lycopene (mg/d) with higher LDL-c (β: 2.030, 95%CI: 0.27, 4.31) and vitamin A intake (mg RAE/d) with lower TNF-α (β: -12.12, 95%CI: -24.71, -0.47) and higher TAC (β: 0.64, 95%CI: 0.001, 1.27). CONCLUSION: Higher intakes of total carotenoids and vitamin A were associated with lower odds of GC and more favorable profiles of inflammatory/oxidative stress biomarkers. These findings support an inverse association between carotenoid-rich dietary patterns and gastric carcinogenesis.