Dairy Consumption and Liver Cancer Risk: A Systematic Review and Dose-Response Meta-Analysis of Observational Studies.

The relationship of dairy consumption and liver cancer risk is still controversial. We conducted a meta-analysis of published cohort and case-control studies to summarize the epidemiologic evidence on the relationship between dairy products consumption and the risk of liver cancer. The literatures were screened from PubMed, EMBASE, and Cochrane Library before May 2020. A total of seven cohort studies and eight case-control studies (5,121 cases) were included. The summary relative risks (RRs) were 1.17 (95% CI: 0.87‒1.57) and 1.08 (95% CI: 0.78‒1.51) for milk and total dairy, respectively. 0.50 (95% CI: 0.27-0.91) and 1.16 (95% CI: 0.83-1.52) were yogurt, cheese, and curd. Subgroup analysis revealed that study duration, alcohol, and design were associated the RRs. Dose-response analysis showed that the liver cancer risk was decreased by 5.4% ( for linear trend = 0.002) with a 40 g/day increment of yogurt intake. These results suggested that total dairy, milk, cheese, and curd were positive associations with the liver cancer risk although they were not statistically significant, however higher yogurt intake would reduce the risk. Further studies are necessary to verify the relationship of dairy foods with cancer.