Researchers from the National Cancer Institute in Bethesda, Maryland, used data from previous health surveys to determine if decaffeinated coffee shares the liver benefits of its regular counterpart. Lead researcher Dr. Quian Xiao of the NCI said in a statement that “Prior research [had] found that drinking coffee may have a possible protective effect on the liver,” but that it had not previously been clear if that effect extended to decaf.
About 65% of Americans drink coffee with their breakfast. A new report from the National Coffee Association shows that daily coffee intake has remained steady at about 61% in 2014, though the types of coffee consumed have shifted; espresso and single-serving gourmet coffees have seen a rise in popularity since last year (increases of 5% and 9%, respectively), while non-gourmet and drip coffee have dropped (decreases of 4% and 5%).
People who choose decaf generally do so in order to avoid the jitters some experience when they consume caffeine, or because of pregnancy or heartburn.
Digging Into Decaf
The new research was based on the National Health and Nutrition Examination Survey, which is overseen by the Centers for Disease Control and Prevention. This survey produces more reliable data than some others because participants are physically examined and undergo blood tests in addition to being interviewed.
The research team examined results from 27,800 people aged 20 or older. Each participant reported their coffee consumption levels for the past 24 hours; the team then compared these answers to markers of liver health discernible in the blood. The results showed that people who reported drinking three or more cups of coffee each day had lower levels of four enzymes (alanine aminotransferase, ALT; aspartate aminotransferase, AST; alkaline phosphatase, ALP; and gamma-glutamyl transaminase, GGT) than participants who did not drink coffee. Elevated levels of these enzymes can indicate damage or inflammation in the liver.
The encouraging results regarding liver health held true whether the participants preferred regular or decaf coffee.
“Our findings link total and decaffeinated coffee intake to lower liver enzyme levels,” Xiao said, adding that further research will be needed to determine what chemical in coffee assists liver function.
Previous studies have linked coffee consumption to lower rates of diabetes, cardiovascular disease, liver disease cirrhosis and liver cancer.
The full results of the new research will be published in the scientific journal Hepatology.