Fish Intake, Dietary Polyunsaturated Fatty Acids, and Lung Cancer: Systematic Review and Dose–Response Meta-Analysis of 1.7 Million Men and Women

To determine the association between fish intake and dietary polyunsaturated fatty acids (PUFA) and incidence of lung cancer. We systematically reviewed and meta-analyzed all available studies to quantify the associations of fish and PUFA consumption with risk of lung cancer. Relative risk (RR) with 95% confidence interval (CI) was calculated. 13 population-based prospective cohort studies involving 1,785,000 participants and two randomized control trials were included. Our study demonstrated that dietary PUFA significant reduced risk of lung cancer for men (RR 0.99, 95%CI 0.98 to 1.00) and the U.S. population (RR 0.99, 95%CI 0.98 to 1.00). Dose-response analysis indicated that a 5 g/day increment of dietary PUFA was associated with 5% lower risk of lung cancer (RR 0.95, 95%CI 0.91 to 0.99). In addition, PUFA supplementation is significant improved overall survival in patients with lung cancer (RR 1.98, 95%CI 1.09 to 3.59). Our study showed an inverse association between dietary PUFA and risk of lung cancer in males and among the U.S. population. Although smoking cessation is the single biggest factor associated with lung cancer risk reduction, this study adds to a growing body of evidence that diet may have a role in modestly reducing lung cancer risk.