Statement Highlights:
- It is estimated that about one in four adults worldwide has an abnormal build-up of fat in the liver, called non-alcoholic fatty liver disease (NAFLD).
- NAFLD can lead to permanent liver damage, and heart disease is the leading cause of death in people with fatty liver disease.
- Because NAFLD is often missed in routine medical screening, the new American Heart Association scientific statement raises awareness and understanding about its link to heart disease and to outline how to prevent and diagnose the condition.

It is estimated that about one in four adults worldwide has a liver condition that is a risk factor for heart disease, according to a new American Heart Association scientific statement published today in the Association’s peer-reviewed journal Arteriosclerosis, Thrombosis, and Vascular Biology. The condition, called nonalcoholic fatty liver disease (NAFLD), occurs when abnormally elevated amounts of fat are deposited in the liver, sometimes resulting in inflammation and scarring. The prevalence of NAFLD is an estimate, given the challenges in diagnosing the condition, which are detailed in the statement.
An American Heart Association scientific statement is an expert analysis of current research and may inform future guidelines. Professional organizations specializing in gastroenterology have previously published statements on the condition, however, they focus on liver toxicity (including scarring, cirrhosis and liver cancer) rather than heart disease risk. This is the Association’s first statement about NAFLD.
“Nonalcoholic fatty liver disease (NAFLD) is a common condition that is often hidden or missed in routine medical care. It is important to know about the condition and treat it early because it is a risk factor for chronic liver damage and cardiovascular disease,” said P. Barton Duell, M.D., FAHA, chair of the statement writing committee and professor of medicine in the Knight Cardiovascular Institute and Division of Endocrinology, Diabetes and Clinical Nutrition at Oregon Health & Science University in Portland, Oregon.
There are two types of NAFLD: one when only fat is present in the liver (called non-alcoholic fatty liver), and the other when inflammation and scarring are also present (called non-alcoholic steatohepatitis, or NASH). Excess alcohol intake can cause similar fat deposits and liver dysfunction, so the term NAFLD is used to differentiate between disease caused by excess alcohol intake vs. disease without alcohol as the underlying cause.