Nov. 8, 1999 (Dallas) -- Medical experts have been touting the benefits of light alcohol consumption to prevent heart attacks and stroke for some time, but no one knew how a drink or two would affect an injured liver. Now a study from Canadian researchers shows that in rats small amounts of alcohol can actually improve the ability of damaged livers to repair themselves.
This finding may mean that humans who have liver damage that is not alcohol-related may benefit from small amounts of alcohol. Researcher Gerald Y. Minuk, MD, reported the findings here Monday at the 50th annual meeting of the American Association for the Study of Liver Diseases.
Minuk, a professor of medicine at the University of Manitoba at Winnipeg, tells WebMD that his team decided to test the effect of light alcohol consumption, meaning one or two drinks a day, on "the organ principally responsible for metabolizing ethanol" because so many people are following a regimen of one or two drinks per day as part of heart-healthy lifestyles.
"We know that alcohol has two major adverse effects on the liver: It not only can cause liver damage, but it also interferes with the ability of the liver to repair after damage." He says that it was already known that "light alcohol consumption doesn't damage the liver, but we had no idea what effect, if any, light alcohol consumption has on the liver's ability to regenerate."
Minuk and co-authors randomized 86 male rats to receive high, moderate, or light daily doses of alcohol or water for 30 days. They then removed about 70% of the rats' livers. The rats were then maintained on an alcohol-free diet for up to a week. To determine if the remaining portion of the rats' livers had initiated repair, the researchers used DNA tests to find proteins manufactured when the liver is regenerating tissue.
Minuk says that the experiment with rats mimics the effect that a daily drink or two would have on " ... an individual who was otherwise healthy but suddenly had an acute liver injury, such as would be experienced by an adverse reaction to blood pressure medication or because one was infected with a virus such as hepatitis." Both hepatitis B and hepatitis C damage the liver.
"The moderate and heavy alcohol consumption interfered with liver regeneration, whereas the light amounts stimulated regeneration," Minuk says. He says that he and his co-authors are now conducting experiments on rats infected with chronic hepatitis B or C to gauge the effect of light alcohol consumption.
Although the results of the initial animal studies are encouraging, Minuk says, "we are committed to two years of additional research in rats before we would even consider addressing the possibility of a human trial." He says, too, that, "regardless of results of additional experiments, we are absolutely convinced that light alcohol consumption has no role to play in alcohol-related liver disease or any alcohol dependency problem."