Coffee good for the liver, even if decaffeinated, study
Drinking coffee, caffeinated or not, may benefit liver health, according to new research from the National Cancer Institute in Bethesda, Maryland.
The study, published in Hepatology, a journal of the American Association for the Study of Liver Diseases, showed that higher coffee consumption, regardless of caffeine content, was linked to lower levels of abnormal liver enzymes. The researchers said this suggested that chemical compounds in coffee other than caffeine may help protect the liver.
Coffee consumption is highly prevalent with more than half of all Americans over 18 drinking on average three cups each day according to a 2010 report from the National Coffee Association. Moreover, the International Coffee Association reports that coffee consumption has increased one percent each year since the 1980s, increasing to two percent in recent years.
Australian Food News reported in May 2014 that market research organisation Roy Morgan Research had found that although coffee consumption by Australian adults had declined slowly in the last decade from 10.5 cups to 9.2 cups per week, cafe visitation and ownership of coffee-making machines was on the rise.
Coffee consumption associated with other health benefits
Previous studies found that coffee consumption may help lower the risk of developing diabetes, cardiovascular disease, non-alcoholic fatty liver disease, cirrhosis, and liver cancer.
“Prior research found that drinking coffee may have a possible protective effect on the liver,” said Dr Qian Xiao from the National Cancer Institute. “However, the evidence is not clear if that benefit may extend to decaffeinated coffee,” she said.
For the present study researchers used data from the US National Health and Nutrition Examination Survey (NHANES, 1999-2010). The study population included 27,793 participants, 20 years of age or older, who provided coffee intake in a 24-hour period.
The research team measured blood levels of several markers of liver function, including aminotransferase (ALT), aminotransferase (AST), alkaline phosphatase (ALP) and gamma glutamyl transaminase (GGT) to determine liver health.
Participants who reported drinking three or more cups of coffee per day had lower levels of ALT, AST, ALP and GGT compared to those not consuming any coffee. Researchers also found low levels of these liver enzymes in participants drinking only decaffeinated coffee.
“Our findings link total and decaffeinated coffee intake to lower liver enzyme levels,” said Dr Xiao. “These data suggest that ingredients in coffee, other than caffeine, promote liver health. Further studies are needed to identify these components,” she said.