In a research paper published in journal ‘Hepatology’ of the American Association for the Study of Liver Diseases, the researchers said their findings show that higher coffee consumption, regardless of caffeine content, was linked to lower levels of abnormal liver enzymes, which means chemical compounds in coffee other than caffeine actually help protect the health of the liver.
Compared to existing research on positive relationship between coffee and liver, the new evidence brings in the decaffeinated coffee into focus. “Prior research found that drinking coffee may have a possible protective effect on the liver. However, the evidence is not clear if that benefit may extend to decaffeinated coffee,” said lead researcher Dr. Qian Xiao of NCI in Bethesda, Maryland.
The study was based on 27,793 participants, aged 20 or older, in the US National Health and Nutrition Examination Survey (1999-2010) for coffee intake in 24-hour span. Serum levels of aminotransferase (ALT), aminotransferase (AST), alkaline phosphatase (ALP) and gamma glutamyl transaminase (GGT) were measured.
“We examined the relationship between coffee intake and enzymatic levels using weighted multiple variable logistic (abnormally elevated levels of enzymes) and linear regression (continuous enzymatic levels)… Higher intakes of coffee, regardless of its caffeine content, were associated with lower levels of liver enzymes,” concluded the researchers.
Results Total coffee consumption was inversely associated with abnormal levels of all four liver enzymes and continuous levels of AST, ALP and GGT. Compared to those reporting no coffee consumption, participants who consumed 3 cups per day had an odds ratio (OR) (95% confidence interval (CI)) of 0.75 (0.63, 0.89)), 0.82 (0.68, 0.98), 0.73 (0.55, 0.95) and 0.69 (0.57, 0.83) for abnormal levels of ALT, AST, ALP and GGT, respectively. Similar inverse associations were found with decaffeinated coffee intake and abnormal levels of ALT (OR ≥2 vs0 cup/d: 0.62 (0.41, 0.94)), AST (0.74 (0.49, 1.11)), and GGT (0.70, 0.49-1.00), said the researchers in their paper.
Coffee consumption is high in half of the world including the US, Asia and Europe. Half of Americans over 18 take an average of three cups each day, according to the National Coffee Association. The International Coffee Association reports that coffee consumption has increased one percent each year since the 1980s, and currently it is increasing at 2%.
Other research findings show that coffee consumption may help lower the risk of developing diabetes, cardiovascular disease, non-alcoholic fatty liver disease, cirrhosis, and liver cancer but caffeine being a major source of threat, it was advised that over consumption of coffe leads to dangerous consequences.
“Our findings link total and decaffeinated coffee intake to lower liver enzyme levels. These data suggest that ingredients in coffee, other than caffeine, may promote liver health. Further studies are needed to identify these components,” said Qian Xiao.