Dietary Polyunsaturated Fat Intake in Relation to Head and Neck, Esophageal, and Gastric Cancer Incidence in the National Institutes of Health-AARP Diet and Health Study.

Recent epidemiologic studies have examined the association of fish consumption with upper gastrointestinal cancer risk, but the associations with n-3 and n-6 polyunsaturated fatty acid (PUFA) subtypes remain unclear. Using the National Institutes of Health-AARP Diet and Health Study (United States, 1995-2011), we prospectively investigated the associations of PUFA subtypes, ratios, and fish with the incidence of head and neck cancer (HNC; n = 2,453), esophageal adenocarcinoma (EA; n = 855), esophageal squamous cell carcinoma (n = 267), and gastric cancer (cardia: n = 603; noncardia: n = 631) among 468,952 participants (median follow-up, 15.5 years). A food frequency questionnaire assessed diet. Multivariable-adjusted hazard ratios were estimated using Cox proportional hazards regression. A Benjamini-Hochberg (BH) procedure was used for false-discovery control. Long-chain n-3 PUFAs were associated with a 20% decreased HNC and EA risk (for HNC, quintile5 vs. 1 hazard ratio = 0.81, 95% confidence interval: 0.71, 0.92, and BH-adjusted Ptrend = 0.001; and for EA, quintile5 vs. 1 hazard ratio = 0.79, 95% confidence interval: 0.64, 0.98, and BH-adjusted Ptrend = 0.1). Similar associations were observed for nonfried fish but only for high intake. Further, the ratio of long-chain n-3:n-6 was associated with a decreased HNC and EA risk. No consistent associations were observed for gastric cancer. Our results indicate that dietary long-chain n-3 PUFA and nonfried fish intake are associated with lower HNC and EA risk.