Many people think that drinking a little during the week is safe. They assume having several drinks on a Friday or Saturday won’t damage their liver. But new research shows these assumptions may not be true. A study from Keck Medicine of USC warns that even moderate drinkers can damage their liver if they drink heavily on certain days. The research appears in the journal Clinical Gastroenterology and Hepatology. The study focused on people with metabolic dysfunction-associated steatotic liver disease (MASLD).
MASLD is the most common liver disease in the U.S., affecting about one in three adults. It is linked to conditions like obesity, diabetes, high blood pressure, and high cholesterol. Researchers found that people with MASLD who drink heavily on a single day each month face a much higher risk of liver fibrosis, which is harmful scarring of the liver. For women, heavy drinking is four or more drinks in one day. For men, it’s five or more drinks in one day. The study revealed that those who drink a lot at once are three times more likely to develop serious liver damage than people who drink the same total amount spread out over time. Younger adults and men were more likely to drink heavily in this way.
The more drinks consumed in one session, the greater the liver damage. “This study is a major warning,” said Dr. Brian P. Lee, a liver specialist at Keck Medicine and the lead researcher. “Doctors usually focus on the total alcohol someone drinks over time. But our findings show that how people drink matters just as much. Occasional heavy drinking is dangerous, even for moderate drinkers.”
How the Study Was Done
Dr. Lee and his team analyzed data from over 8,000 adults who took part in the National Health and Nutrition Examination Survey between 2017 and 2023. This survey collects information about health across the United States.
The researchers studied the link between episodic heavy drinking and advanced liver fibrosis. They compared people with MASLD who drank heavily once a month to those who did not. They matched participants by age, sex, and average weekly alcohol consumption. Even among people who drank the same total amount, those who had occasional heavy drinking were far more likely to develop liver scarring. About 16% of MASLD patients reported episodic heavy drinking, and more than half of all adults in the study said they drank heavily at least once a month.
Why Occasional Heavy Drinking Is Harmful
Dr. Lee explained that drinking a large amount of alcohol at once can overwhelm the liver. This can cause inflammation and scarring. People with MASLD are even more at risk. Conditions such as obesity, high blood pressure, and diabetes already increase liver disease risk. Adding heavy drinking worsens it. Alcohol-related liver disease has more than doubled in the past 20 years, according to Dr. Lee. He believes the increase is partly because more people drank during the pandemic and because more adults have risk factors for MASLD.
What This Means for the Public
Even moderate drinkers should be careful about binge drinking. Drinking heavily even once a month can be dangerous, especially for those with MASLD. “These results may apply to more people than just those with MASLD,” Dr. Lee said. “More than half of U.S. adults report heavy drinking at least occasionally. We need more research and public awareness to prevent liver disease.” In short, spreading drinks evenly over time is safer than drinking a lot in one day. People should avoid binge drinking, even if they normally drink moderately. Your drinking habits, not just the quantity, also impact your liver health. Occasional heavy drinking is a risk many people might not realize, but now the evidence is clear.
