Dietary fatty acids and risk of hepatocellular carcinoma in the Singapore Chinese health study

Background & Aim: Lipidomic signature of lipid metabolism suggests that omega-6 polyunsaturated fatty acids (PUFA) may play a role in oncogenesis of hepatocellular carcinoma (HCC). Hence, we examined the association between dietary fatty acids and risk of HCC. Methods: We used data from the Singapore Chinese Health Study, a population-based prospective cohort of 63 257 Chinese men and women aged 45-74 years enrolled between 1993 and 1998. Information on current diet assessed via a validated semi-quantitative food frequency questionnaire, medical history and lifestyle factors were obtained through in-person interview, and incidence of HCC recorded through 31 Dec 2010. We also examined the association between dietary fatty acids and HCC risk using a case-control set of 92 cases and 274 controls with available serological biomarkers of chronic infections with hepatitis B virus (HBV) and hepatitis C virus (HCV) nested within this cohort. Results: Among the dietary fat components examined, which included saturated, monounsaturated, omega-3 and omega-6 PUFA, only omega-6 PUFA intake displayed a dose-dependent, positive association with HCC risk (p for trend = 0.02). Compared to the lowest quartile, the hazard ratio for the highest quartile intake was 1.49 [(95% confidence interval (CI): 1.08-2.07)]. In the nested case-control study, only among individuals negative for serology markers of chronic infection with HBV or HCV, those who consumed above median levels of dietary omega-6 PUFA had increased HCC risk (odds ratio = 4.36, 95% CI = 1.59-11.94) compared to those with lower intake. Conclusion: Dietary omega-6 PUFA may be implicated in the risk of non-viral hepatitis related HCC.