LOS ANGELES — Americans who drink heavily are more than twice as likely to develop significant liver disease compared to 20 years ago, according to a new Keck Medicine of USC study published today in Clinical Gastroenterology and Hepatology.
"Alcohol-related liver disease is the main cause of liver-related death and these results are a major wakeup call to the dangers of drinking," said Brian P. Lee, MD, MAS , a hepatologist and liver transplant specialist with Keck Medicine and lead author of the study.
The study also sheds light on the demographics of American drinkers, uncovering that four groups make up a greater share of heavy drinkers than they did 20 years ago — women, adults 45 and older, those living in poverty and people with metabolic syndrome, a cluster of conditions that together raise the risk of coronary heart disease, diabetes and stroke. Previous studies have already associated these groups with a higher risk of liver disease when exposed to alcohol.
"These findings — the first comprehensive look at the demographics of heavy drinking and their relation to liver disease since the 1990s — provide important new information about which population groups may need more intervention to curb alcohol use and may also explain the rise in liver disease over the years," said Lee.
Additionally, the study showed that the average drinking rate in America was unchanged over the last 20 years before the COVID-19 pandemic, suggesting that factors beyond alcohol quantity, such as changing health and demographic profiles, may be contributing to the rise in liver disease.
"Our results show that the makeup of the American public with heavy alcohol consumption has changed compared to 20 years ago," said Lee.
Lee and his fellow researchers analyzed data from the National Health and Nutrition Examination Survey, which assesses the health and nutritional status of adults and children in the United States, from 1999-2020, the most recent year for which complete data was available.
They tracked the total increase in significant liver disease — a stage of liver disease when the liver forms scar tissue that impairs liver function that is often caused by heavy drinking. The study examined the demographic and health profiles of adults 20 or older who drank heavily. According to the Centers for Disease Control and Prevention, heavy drinking is considered eight drinks per week for women and 15 for men.
Lee believes that the study results will provide physicians with necessary updates to better treat patients and hopes they will lead to more screenings and interventions for high-risk populations.
Jennifer Dodge, MPH , assistant professor of research medicine and population and public health sciences with the Keck School of Medicine of USC , was also a study author.
The study was supported by a grant from the National Institute on Alcohol Abuse and Alcoholism, grant number K23AA029752.
These findings build on Lee's previous work, including a February 2025 study that found heavy drinkers with diabetes, high blood pressure or increased waist size had double the risk of advanced liver disease, and a November 2024 study revealing that heavy drinking rose during the COVID-19 pandemic peak and continued for two years afterward.
