Fish Intake Tied to Liver Cancer Risk
The role of nutrition in liver cancer risk has been underrepresented in research, particularly compared to risk factors such as chronic infection with hepatitis B virus (HBV) or hepatitis C virus (HCV). Yet, some studies have indicated that n-3 polyunsaturated fatty acid (n-3 PUFA) may inhibit the promotion and progression stages of carcinogenesis. Fish is a source rich in n-3 PUFA, making it an ideal factor for analysis.
A new study in PLOS ONE reviewed published studies on the role of total fish intake and risk of primary liver cancer in case-control and cohort studies. Ten studies were analyzed, with all but one study hospital-based. A statistically significant inverse association between total fish intake and risk of liver cancer was observed; in comparing high vs. low intake, response models indicated that this risk was reduced by 18% and 6% per one serving/week increase, respectively. Although the exact mechanism of action is unknown, it is proposed that n-3 PUFA may inhibit cancer development via molecular biosynthesis, gene transcription and expression, and signal transduction or through its anti-inflammatory effect.
Even with these findings, residual or unknown confounding factors cannot be completely ruled out and not all studies controlled for risk factors such as HBV/HCV status. While this study supports a possible relationship between fish intake and liver cancer prevention, future well-designed studies are needed.