April 9, 2019

An article appearing on Dec. 7, 2018, in the journal Nutrients reports an association between long-term zinc supplementation and better liver function as well as a lower risk of liver cancer in men and women with liver diseases.

The current study included 267 patients with chronic liver diseases, including hepatitis B, hepatitis C, alcohol-associated cirrhosis, nonalcoholic steatohepatitis and autoimmune hepatitis plus primary biliary cholangitis. In the study, 196 participants received zinc, and 71 participants received no zinc supplementation. Liver function and events that included death or the development of liver cancer or liver failure were assessed at least every six months during the study. Subjects were followed for an average of 40 months.

Not surprisingly, plasma zinc levels increased more among participants who received higher doses of zinc while remaining low in the group that did not receive the supplement. While participants who did not receive zinc experienced deterioration in indicators of liver function after three years, no significant changes occurred in the zinc-supplemented group. Additionally, subjects who received zinc had a lower risk of developing hepatocellular carcinoma, the most common type of primary liver cancer in adult patients.

Among participants whose serum zinc concentrations were at least 70 micrograms per deciliter (mcg/dL) at six months, the cumulative incidence rates of events including death, development of liver cancer and appearance of liver failure at three years were significantly lower in comparison with subjects who had lower serum zinc levels. Those whose zinc levels were 90 mcg/dL or higher had an event incidence rate of 0% at three years.

“Zinc plays a pivotal role in various zinc enzymes, which are crucial in the maintenance of liver function,” observe Atsushi Hosui of Osaka-Rosai Hospital in Japan and colleagues. Inadequate dietary intake, impaired absorption and increased urinary excretion of the mineral are among potential mechanisms that decrease zinc levels in those with chronic liver diseases.

“This is the first report to clarify that zinc administration improves liver function and decreases the cumulative incidence of events and the incidence of hepatocellular carcinoma in patients with chronic liver diseases, over the course of long-term follow-up,” the authors announce. “The effectiveness does not depend on the etiology of the chronic liver disease; thus, zinc administration is equally useful for patients with a hepatitis C virus infection, hepatitis B virus infection, nonalcoholic steatohepatitis, or alcohol-related liver diseases. It is necessary to highlight the importance of zinc and to start administering zinc preparations in the clinical setting.”