Over time, excessive drinking can lead to several chronic conditions, such as fatty liver disease and cirrhosis. But there’s new evidence that aerobic exercise may protect the liver.
“Excessive alcohol consumption is one of the most common causes of chronic liver failure,” says Jamal Ibdah, professor of medicine and chair in cancer research at the University of Missouri School of Medicine.
“We know from previous research that chronic and binge drinking causes modifications to protein structures within the liver, resulting in irreversible damage. In our current study we wanted to see whether increased levels of aerobic fitness could prevent alcohol-related liver damage.”
For the study, published in the journal Biomolecules, researchers used rats bred for high activity, or “runner rats,” to test if increased metabolism protected the liver against fatty deposits and inflammation.
One group of rats was exposed to chronic alcohol use for six weeks and compared to a second group that was not exposed to alcohol during the same time period.
“As expected, we found that fatty deposits were greater in the livers of the chronic alcohol group,” Ibdah says. “However, chronic alcohol ingestion did not cause significant inflammation in the liver. Higher physical activity levels seemed to protect against the metabolic dysfunction that eventually leads to irreversible liver damage.”
The research also shows that chronic drinking caused no discernible increase in free fatty acids, triglycerides, insulin, or glucose in the blood of the group exposed to alcohol as compared to the control group.
“This is significant because chronic alcohol ingestion may reduce insulin effectiveness over time, leading to elevated blood insulin and sugar levels,” Ibdah says. “With chronic use, we would expect to see these levels much higher than the control group, yet surprisingly, they were about the same.”
More research is needed to better understand how increased aerobic fitness provides oxidative protection against chronic alcohol use. However, understanding this mechanism may lead to eventual treatments for chronic alcohol-related liver damage.
Other researchers from the University of Missouri and from the University of Michigan are coauthors of the study. The National Institutes of Health, the NIH Office of Research Infrastructure Programs, and the US Department of Veterans Affairs funded the work.