People with nonalcoholic fatty liver disease (NALFD) who consume alcohol in modest amounts, no more than one or two servings per day, are half as likely to develop hepatitis as non-drinkers with the same condition, a new study has claimed.
NALFD is the most common liver disease in the United States, affecting up to one third of American adults.
It is characterized by abnormal fat accumulation in the liver. The specific cause or causes is not known, though obesity and diabetes are risk factors. Most patients with NAFLD have few or no symptoms, but in its most progressive form, known as nonalcoholic steatohepatitis or NASH, there is a significantly heightened risk of cirrhosis, liver cancer and liver-related death.
NALFD is also a known risk factor for cardiovascular disease (CVD). Patients with NAFLD are approximately two times more likely to die from coronary heart disease than from liver disease.
The national team of scientists led by researchers at the University of California, San Diego School of Medicine wanted to know if the well-documented heart-healthy benefits of modest alcohol consumption outweighed alcohol's negative effects.
"We know a 50-year-old patient with NAFLD has a higher risk of CVD," Jeffrey Schwimmer, senior author of the study, said.
"Data would suggest modest alcohol consumption would be beneficial (in reducing the patient's CVD risk) if you don't take liver disease into account. When you do take liver disease into account, however, the usual medical recommendation is no alcohol whatsoever," he said.
Schwimmer and colleagues discovered that the benefits of modest alcohol consumption were compelling, at least in terms of reducing the odds of patients with NAFLD from developing more severe forms of the disease.
Patients with NASH are 10 times more likely to progress to cirrhosis, the final phase of chronic liver disease. Cirrhosis is the 12th leading cause of death in the U.S., killing an estimated 27,000 Americans annually.
"Our study showed that those people with modest alcohol intake - two drinks or less daily - had half the odds of developing NASH than people who drank no alcohol.
"The reasons aren't entirely clear. It's known that alcohol can have beneficial effects on lipid levels, that it increases 'good' cholesterol, which tends to be low in NAFLD patients. Alcohol may improve insulin sensitivity, which has a role in NAFLD. And depending upon the type of alcohol, it may have anti-inflammatory effects," he said.
The study has been published online in The Journal of Hepatology.