You know excessive drinking can cause fatty liver disease and even liver failure. But you might not know that alcohol abuse (more than three or four drinks on an occasion) is the culprit of nearly 88,000 deaths in the U.S. each year, according to stats from the Centers for Disease Control and Prevention.
While we'd never condone heavy drinking, there is a certain form of exercise that might be able to protect your liver against this alcohol-related inflammation and injury if you do ever go overboard. (Note: That's not to say it's tit for tat—no amount of sweat can undo the effects of an alcohol problem. If you think you have one, talk to your doctor or someone you trust.)
A new University of Missouri School of Medicine study found aerobic exercise can bulletproof your body in more ways than one. Though the research was conducted on rats, researchers say cardio promotes a healthier mitochondria (the structure that shells out energy for our cells) and a higher-working metabolism, which work together to bolster your liver.
"We know from previous research that chronic and binge drinking causes modifications to protein structures within the liver, resulting in irreversible damage,” the lead study authors said in a press release. “In our current study we wanted to see whether increased levels of aerobic fitness could prevent alcohol-related liver damage."
The team put rats on treadmills, separating the ones with an intrinsically higher capacity to run for long distances, and breeding them with one another to create "runner rats." These rats were used to see if increased metabolism would have a measurable influence and protect the liver against fatty deposits and inflammation.
In the study, one group of "runner rats" was exposed to chronic alcohol use for six weeks, and a second (control) group of "runner rats" was not. Their diets were managed to ensure all consumed the same number of calories. As the researchers expected, the chronic alcohol group of rats had far more fatty deposits in their livers (a tell-tale sign of alcohol-related liver damage) at the study's conclusion.
But the chronic alcohol ingestion didn't cause any dangerous inflammation in their livers thanks to the rats' high metabolisms and mitochondrion. Aerobic exercise seemed to protect against the metabolic dysfunction that snowballs into irreversible liver damage, the researchers explain. The alcohol abuse didn't cause any noticeable increases in free fatty acids and triglycerides (indicators of heightened risk of heart disease, stroke, obesity and metabolic syndromes), or insulin or glucose (indicator of diabetes) in the rats' blood either.
"This is significant because chronic alcohol ingestion may reduce insulin effectiveness over time, leading to elevated blood insulin and sugar levels," study author Jamal Ibdah, M.D. said in the release. "With chronic use, we would expect to see these levels much higher than the control group, yet surprisingly, they were about the same."
Obviously more research needs to be done to get a better idea of how increased aerobic fitness provides protection against chronic alcohol use. But, Ibdah does speculate these results could be similar in humans. "We've done other studies and found using short bouts of high-intensity interval training and moderate exercise in humans both result in reduced and reversed liver damage—though not related to alcohol," he says. Rats are obviously an easier model to test alcohol-related liver damage on, afterall.
But the understanding that a higher metabolism from aerobic activity could prevent liver inflammation may lead to eventual treatments for chronic alcohol-related liver damage. Although, again, we have to point out that limiting your alcohol consumption in the first place is the best bet against dodging liver damage.
In short: exercise more, booze less.