Mediterranean diet and hepatocellular carcinoma

Abstract

Background & aims: Hepatocellular carcinoma (HCC) has a very poor prognosis and any effort to identify additional risk factors, besides those already established, would be important for the prevention of the disease. Data on the role of diet on HCC risk are still controversial.

Methods: We have evaluated the association of adherence to the Mediterranean diet with HCC risk, as well as the interaction of this dietary pattern with chronic hepatitis infection, by combining two case-control studies undertaken in Italy and Greece, including overall 518 cases of HCC and 772 controls. Adherence to the traditional Mediterranean diet was assessed through the Mediterranean diet score (MDS), which ranges between 0 (lowest adherence) and 9 (highest adherence). Odds ratios (OR) for HCC were obtained through multiple logistic regression models, controlling for potentially confounding factors, including chronic infection with hepatitis B/C viruses.

Results: Compared to MDS of 0-3, the ORs for HCC were 0.66 (95% confidence interval (CI), 0.41-1.04) for MDS equal to 4 and 0.51 (95% CI, 0.34-0.75) for MDS ⩾ 5, with a significant trend (p<0.001). The detrimental effect of poor adherence to Mediterranean diet on HCC risk was disproportionally high among those chronically infected with hepatitis B and/or C viruses, with a suggestion of super-additive interaction, albeit statistically non-significant.

Conclusions: Closer adherence to the Mediterranean diet appears to be protective against HCC. Our results also point to potential benefits from adhering to a Mediterranean dietary pattern for patients chronically infected with hepatitis viruses.

Keywords: BMI; CI; Case-control study; Dietary habits; HBV; HBsAg; HCC; HCV; Liver cancer; MDS; Mediterranean diet; OR; RERI; Risk factors; S; anti-HCV; antibodies against hepatitis C virus; body mass index; confidence interval; excess risk due to interaction; hepatitis B surface antigen; hepatitis B virus; hepatitis C virus; hepatocellular carcinoma; mediterranean diet score; odds ratio; synergy index.