People may assume that if they drink lightly during the week or month, heavy drinking on the occasional Friday or Saturday may not cause their liver harm. But new research suggests otherwise. Researchers from Keck Medicine of USC discovered that people with metabolic dysfunction–associated steatotic liver disease (MASLD), the most common liver condition in the United States, affecting one-in-three adults, face a significantly higher risk of liver fibrosis, or harmful scarring of the liver, if they engage in episodic heavy drinking.

Episodic heavy drinking is defined as four or more drinks in one day for women and five or more drinks in one day for men, at least once a month.

Those who consume large amounts of alcohol in a single day at least once per month are three times more likely to develop advanced liver fibrosis than individuals who spread out the same total alcohol intake over time, according to the findings.

Younger adults and men were more likely to report episodic heavy drinking, and the more drinks consumed at one time, the more liver fibrosis people tended to have.

“This study is a huge wake-up call because traditionally, physicians have tended to look at the total amount of alcohol consumed, not how it is consumed, when determining the risk to the liver,” said principal investigator Brian P. Lee, MD. “Our research suggests that the public needs to be much more aware of the danger of occasional heavy drinking and should avoid it even if they drink moderately the rest of the time.” 

The findings are the result of analyses of data from more than 8,000 adults participating in the US National Health and Nutrition Examination Survey. More than one-half of the adults included in the study reported episodic heavy drinking and almost 16% of patients with MASLD were episodic heavy drinkers.

Comparing episodic drinkers to people with MASLD who were not episodic drinkers enabled the researchers to reach the conclusion that episodic heavy drinkers with MASLD had nearly three times higher odds of experiencing advanced liver fibrosis.

Lee speculates that episodic heavy drinking can harm the liver both directly and indirectly. Drinking large amounts of alcohol at once can overwhelm the liver and increase inflammation, which leads to scarring and damage.

People with MASLD may be particularly at risk, as Lee’s previous research has shown, because obesity, high blood pressure and other conditions associated with MASLD can more than double liver disease risk.

To read the abstract for the study, published in Clinical Gastroenterology and Hepatology, click here